KR101372869B1 - Process and system for laser annealing and laser-annealed semiconductor film - Google Patents

Abstract

It is an object of the present invention to provide a laser annealing technique in which an amorphous semiconductor film can be highly crystallized on the whole surface, and the amorphous semiconductor film can be a lateral crystal film having almost no granular crystal parts on the entire surface and a seamless. .

To this end, laser annealing is performed under conditions in which the granular crystal portion and the amorphous portion are melted and the lateral crystal portion is not melted, and the laser light irradiation conditions in the granular crystal portion are amorphous so as to satisfy the following formula (1). The laser annealing is performed in place of the laser light irradiation conditions in the portion.

EA-EP | <| EA-EPs |. (One)

(EA: absorbed light energy per unit area of laser light in the amorphous portion. EPs: absorbed light energy per unit area of laser light in the granular crystal portion when irradiated laser light under the same laser light irradiation conditions as the amorphous portion. EP: actual absorbed light energy per unit area of laser light in the granular crystal part)

Laser annealing technology, semiconductor film, semiconductor device, electro-optical device

Description

Laser annealing technology, semiconductor film, semiconductor device, and electro-optical device {PROCESS AND SYSTEM FOR LASER ANNEALING AND LASER-ANNEALED SEMICONDUCTOR FILM}

The present invention relates to a laser annealing method and a laser annealing apparatus for performing laser annealing on a annealed semiconductor film made of an amorphous semiconductor.

The present invention also relates to a semiconductor film produced by the laser annealing method, a semiconductor device such as a thin film transistor (TFT) using the semiconductor film, and an electro-optical device using the semiconductor device.

In electro-optical devices such as electroluminescent (EL) devices and liquid crystal devices, an active matrix driving method is widely adopted. In the active matrix type, a plurality of pixel electrodes are arranged in a matrix, and these pixel electrodes are driven through a pixel switching TFT provided corresponding to each pixel electrode, for example.

In the above electro-optical device, a driving unit including a pixel portion in which a plurality of pixel electrodes and pixel switching TFTs are formed in a matrix on the same substrate, and a driving circuit configured using a plurality of driving circuit TFTs for driving the pixel portion. It may be installed.

An amorphous or polycrystalline silicon film is widely used for the active layer of the TFT. In consideration of device characteristics such as carrier mobility, the silicon film forming the active layer is preferably high in crystallinity. In particular, in the driver circuit TFT, the silicon film forming the active layer is preferably high in crystallinity.

In the production of polysilicon TFTs, for example, a laser annealing is performed first by forming an amorphous silicon (a-Si) film, and then annealing by irradiating the film with laser light. Currently, excimer laser light is widely used as the laser light (ELA method). Excimer laser light is a pulse oscillation laser light of ultraviolet region of 308 nm or less, and the polycrystal produced | generated by ELA method is a granular crystal with a small crystal grain size normally. This is not dependent on the crystalline nature of the silicon film, but the absorption rate of the excimer laser light absorbed by the silicon film is large, and energy is absorbed largely on the surface of the silicon film, so that a large temperature distribution occurs in the film thickness direction. It is thought to be because it hardly grows (paragraph 0005,0036 etc. of patent document 2).

By irradiating laser beam with respect to the amorphous silicon film using a continuous oscillation laser light of a wavelength range of 350 nm or more, lateral crystals having a large grain size extending in the relative scanning direction can be grown (Patent Document 2). Paragraph 0006 etc.).

In the laser head using the continuous oscillation laser light with the oscillation wavelength of 350 nm or more, the width of the beam spot to which annealing energy capable of lateral crystal growth is given is at most 10 mm. The substrate plane is the xy plane, the main relative scanning direction of the laser light is the x direction, and the negative relative scanning direction is the y direction. In order to anneal the large-area amorphous silicon film formed on the substrate as a whole, it is necessary to repeat the operation of performing relative scanning in the x direction after changing the y position after performing relative scanning in the predetermined y position. Usually, when performing the relative scan of the laser beam in the x direction by shifting the y position, the relative scan of the laser light is performed so that the region to which the laser light is irradiated first and the region to which the laser light is irradiated partially overlap each other.

When the relative scanning of the laser light in the x direction is performed only once without changing the y position, granular crystals with small grains are generated outside the generating region of the lateral crystals (see FIG. 1 of this specification). This is because even if the beam profile of the laser light is controlled, heat is diffused around the irradiation area of the laser light, so that the surface temperature necessary for lateral crystal growth is not reached, but an area that becomes a surface temperature at which granular crystallization is formed occurs. At the end in the area where the laser light is directly irradiated, and / or the laser light is not directly irradiated, but granular crystals (granular poly-Si) are formed in the area where heat is conducted (= immediately outside the area where the laser light is directly irradiated). Is generated.

Next, when the relative position of the laser light in the x direction is performed by shifting the y position, it is considered that the granular crystals generated earlier can be laterally crystallized by irradiating the laser light repeatedly on the granular crystal parts. However, in the wavelength range of 350 nm or more, amorphous silicon (a-Si) and granular crystals (granular poly-Si), which are polycrystalline silicon, have different absorption rates of laser light. Therefore, under the same laser light irradiation conditions, the temperature of the granular crystals is required for lateral crystallization. There is a risk of not reaching. Moreover, as a termination crystal, a lateral crystal grows in an unwanted direction, and there exists a possibility that the growth direction of a lateral crystal may become nonuniform.

Even if the granular crystal can be a lateral crystal in the desired growth direction, granular crystals having small grains are eventually generated outside the lateral crystal generation region, and thus the granular crystal cannot be eliminated. In addition, when the laser light is irradiated again on the laterally grown crystalline portion, the lateral crystal portion may be remelted to change its crystallinity.

Since the granular crystal part has many grain boundaries and poor current characteristics, it is necessary to form the TFT avoiding the granular crystal part. Therefore, in the present state, the laser light is scanned so that the beam end of the laser light does not overlap with the element formation region of the TFT based on the design information of the formation position of the TFT, or the laser light is selectively irradiated only to the element formation region of the TFT. It is necessary to devise.

Patent Literature 1 describes performing lateral crystal growth using a second harmonic (wavelength 532 nm) of an Nd: YAG laser, a second harmonic wave (532 nm) of an Nd: YVO ₄ laser, and the like. The conditions are described. As preferable lateral crystal growth conditions, laser light beam diameter: 2-10 micrometers in a scanning direction, a scanning speed: 300-100000 mm / s, the emission power density when a laser light beam diameter is 3 micrometers: 0.4-2.4 MW / cm <2> (Claims 4, 8, paragraph 0037, etc.) are described. In patent document 1, laser light is selectively irradiated only to the element formation area | region of TFT (FIG. 8 etc.).

Patent Document 2 has a wavelength of visible pulsed laser light (wavelength of 350 nm or more) such as the second harmonic (wavelength 532 nm) of the Nd: YAG laser, which is a solid laser, and a second harmonic of the Nd: YAG laser, for the amorphous silicon film. A laser annealing method for simultaneously irradiating and scanning ultraviolet pulse laser light (less than 350 nm) such as short harmonics so that their irradiation regions partially overlap is described (claims 1, 3, short circuit 0011,0045, FIG. 7, etc.). ).

In Patent Literature 2, granular crystals generated outside of the lateral crystal generation region by irradiation of a visible light pulse laser can be decrystallized by irradiation of ultraviolet pulse laser light, and are irradiated with an ultraviolet pulse laser by re-irradiation of the visible pulse laser light which is out of position. It has been described that the amorphous portion can be lateral crystallized by irradiation of light, and a silicon film with high crystallinity can be obtained as a whole (paragraph 0066, FIG. 20, etc.).

Patent Document 3 discloses that the absorption rate of amorphous silicon of the second harmonic (wavelength 524 or 527 nm) of an Nd: YLF laser is one or more orders of magnitude higher than the absorption rate of crystalline silicon, and preferential to amorphous silicon over crystalline silicon by using such laser light. It is described that laser light is absorbed, amorphous silicon can be preferentially melted and crystallized, and a silicon film with high crystallinity can be obtained (paragraph 0020, etc.).

Patent Literature 4 discloses an amorphous silicon film because the absorption of polycrystalline silicon is smaller than that of amorphous silicon when using laser light in a wavelength range of 390 nm to 640 nm, such as a second harmonic (wavelength 532 nm) of an Nd: YAG laser. It is described that even if the laser light is irradiated to the polycrystalline silicon generated by irradiation with the laser light again, the produced polycrystalline silicon does not melt and its characteristics do not change so much by re-irradiation of the laser light (paragraph 0100). However, as a conventional problem, since the absorption rate of laser light in a small grain of crystal grains of polycrystalline silicon is also reduced, it is impossible to improve the crystallinity of the grains of small grain grains, and a subtle overlapping region is recognized in the human eye. It is described (paragraph 0042).

Then, in patent document 4, it is proposed to adopt the structure of any one of following (1)-(5) in the laser annealing which uses the laser light of the wavelength range of 390-640 nm.

(1) Patent Document 4 proposes to set the irradiation energy density in a very low range within a range in which sufficient carrier mobility is obtained as a TFT (paragraph 0043). Specifically, in the relation between carrier mobility and laser output, the lower limit of the laser output attaining 80% or more mobility relative to the laser output that causes the maximum carrier mobility is set to Elow and the upper limit is set to Ehlgh. It is proposed to set the laser output E satisfying E ≤ (Ehigh + Elow) / 2 (claim 1).

Patent Document 4 discloses polycrystalline silicon, namely granular crystals, produced in the region at the end of the first scan by forcibly lowering the laser output than the laser output causing the maximum carrier mobility within a range where sufficient carrier mobility is obtained as a TFT. It is described that the crystal grain size can be made small, and in the second scan, the granular crystal can be easily remelted and the crystallinity can be improved (paragraph 0048).

(2) In Patent Document 4, it is proposed that the length L of the inclined region at the end of the light beam is set short, and preferably 3 mm or less (claim 3, paragraph 0043). Patent Literature 4 describes that the above-described configuration can reduce the polycrystallization region in the inclined region of the first scan, that is, the region where granular crystals are produced, and make it possible to prevent the deterioration of the characteristic of the overlapping region from being noticed. 0050).

(3) In patent document 4, it is proposed to increase the laser light intensity of the 2nd scan in the inclination area | region of the light beam tip compared with 1st scan (claim 5, paragraph 0043). In the above configuration, since the beam having a higher light intensity is irradiated to the region at the end of the first scan, it is described that the granular crystal can be easily remelted and the crystallinity can be improved (paragraph 0702). .

Further, in the configuration of (3), the reflective film is formed in a predetermined region of the substrate stage, and the laser light is reflected from the substrate stage to the overlapped region of the laser light, so that the light intensity is higher than that in the second scan with respect to the region at the end of the first scan. The form of irradiating a high beam is described (claims 9, 10, paragraphs 0104, 0056, Figs. 15, 17).

Patent Literature 5 discloses a first laser light having a wavelength of 5 × 10 ³ / cm or more with respect to amorphous silicon and an absorption coefficient of amorphous silicon with 5 × 10 ² / cm or less and amorphous silicon in a molten state. It has been proposed to simultaneously irradiate a second laser light having a wavelength with an absorption coefficient of 5 × 10 ³ / cm or more (claim 1). For example, it is described to use harmonics of a solid laser such as a YAG laser as the first laser light, and to use a fundamental wave of the same solid laser as the second laser light (paragraphs 0444,0084). In such a configuration, the second laser light is not absorbed by ordinary silicon, but is well absorbed by the portion melted by the irradiation of the first laser light, so that the beam profile can be flattened and the generation region of the granular crystal can be made small. It is described that the lateral crystal region can be enlarged (paragraphs 0015,0011 (b)).

[Patent Document 1] Japanese Unexamined Patent Publication No. 2005-217209

[Patent Document 2] Japanese Unexamined Patent Publication No. 2005-72183

[Patent Document 3] Japanese Unexamined Patent Publication No. 2004-152978

[Patent Document 4] Japanese Unexamined Patent Publication No. 2005-259809

[Patent Document 5] Japanese Unexamined Patent Publication No. 2004-297055

In the laser annealing techniques described in Patent Literatures 2 to 5, various designs have been made focusing on the difference between the absorption characteristics with respect to the wavelength of the laser light and the absorption characteristics with respect to the wavelength of the laser light of the polycrystalline silicon.

For example, FIGS. 5A and 5B (micrographs) of Patent Document 5 show that the region of the lateral crystal can be widened by employing the laser annealing method described in Patent Document 5. FIG. However, Fig. 5 (a) and (b) of Patent Document 5 still show that a granular crystal having a small particle size is still formed outside the lateral crystal.

Paragraph 0009 of patent document 2 describes that substantially whole surface lateral crystallization is possible. However, referring to Figs. 8, 13, 14, and the like of Patent Document 2, although it can roughly crystallize in the main scanning direction from this method even if it is roughly seen, it is assumed that granular crystal regions or amorphous regions always occur in the sub-scanning direction. I think.

In this method, since the rectangular beam is pulsed, the rectangular beam is discontinuously irradiated. Therefore, it is thought that a granular crystal region or an amorphous region in which no lateral crystal is formed in both the main scanning direction and the sub scanning direction is formed along the circumference of the rectangular beam. The granular crystal region or the amorphous region formed in both the main scanning direction and the sub scanning direction along the circumference of the rectangular beam does not reanneal all of the granular crystal region or the amorphous region even when the laser annealing is shifted out of position. A granular crystal region or an amorphous region always occurs.

In addition, in patent document 2, since the granular crystal part is decrystallized, high irradiation energy is needed as shown in FIG. It is considered that such high energy irradiation causes problems such as remelting of lateral crystals and crystallization of granules.

That is, in the prior art, even if lateral crystallization is possible in the main scanning direction, it is not possible to avoid leaving granular crystal parts or the like on the joint when viewed in the sub-scanning direction. In addition, even if it is possible to realize that no granular crystal parts or the like remain in the joint, for example, it was impossible to eliminate the joint.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to make the amorphous semiconductor film substantially high in total surface crystallization, and the amorphous semiconductor film can be made into a lateral crystal film having almost no granular crystal parts in the entire surface and having no seams. It is an object to provide a laser annealing technique.

Another object of the present invention is to provide a semiconductor film having high crystallinity and suitable as an active layer of a thin film transistor (TFT), a semiconductor device such as a TFT using the same, and an electro-optical device.

In the laser annealing method of the present invention, lateral crystals are grown by irradiating laser light to a region of a annealed semiconductor film made of an amorphous semiconductor under laser growth conditions.

Further, the laser annealing is again performed on a region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the non-crystallized crystals by shifting the anneal regions to perform lateral crystallization. In the laser annealing method performed at least once,

The laser annealing is carried out under the condition that the granular crystalline portion and the amorphous portion of the annealed semiconductor film are fused and the lateral crystalline portion of the annealed semiconductor film is not fused,

The laser annealing is performed by changing the laser light irradiation conditions in the granular crystal portion to the laser light irradiation conditions in the amorphous portion so as to satisfy the following formula (1).

The laser annealing device of the present invention includes a laser head equipped with a single or a plurality of laser light oscillation sources,

One region of a annealed semiconductor film made of an amorphous semiconductor is subjected to laser annealing to irradiate laser light under conditions in which lateral crystals grow, thereby growing lateral crystals,

Further, the laser annealing is again performed on the region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the non-crystallized crystals by shifting the anneal regions to perform lateral crystallization. In the laser annealing apparatus that is performed one or more times,

The granular crystal portion and the amorphous portion of the pyrianneal semiconductor film are melted, and the lateral crystal portion of the pyrianneal semiconductor film is set to a laser light irradiation condition that does not melt,

Moreover, the laser light irradiation conditions in the said granular crystal part are changed from the laser light irradiation conditions in the said amorphous part so that following formula (1) may be satisfied.

| EA-EP | <| EA-EPs | (One)

(In the formula (1)

EA is the absorbed light energy per unit area of laser light in the amorphous portion,

EPs is the absorbed light energy per unit area of the laser light in the granular crystal part when the laser light is irradiated under the same laser light irradiation conditions as the amorphous part,

EP represents the actual absorbed light energy per unit area of laser light in the granular crystal part, respectively.)

Granular crystals are produced at an end in a region where the laser light is directly irradiated, and when laser light is not directly irradiated but is generated in a region where heat is conducted (= immediately outside the region where the laser light is directly irradiated) and In some cases, these regions may be generated.

In the present specification, "laser annealing" includes annealing of a region to which laser light is directly irradiated, and an annealing of a region where laser light is not directly irradiated but heat is conducted to change the crystal state.

In the laser annealing apparatus of the present invention, it is preferable that the laser light irradiation conditions in the granular crystal portion are changed from the laser light irradiation conditions in the amorphous portion so as to satisfy the following formula (1A).

EP ≒ EA. (1A)

(EP and EA in Formula (1A) are the same as above.)

In the laser annealing apparatus of the present invention, it is preferable that the laser annealing conditions satisfy the following formula (2A) or (2B).

IL ≒ IA. (2A),

IL <IA. (2B)

(In formulas (2A) and (2B),

IA is the irradiation light energy per unit area of laser light in the amorphous portion,

IL represents the irradiation light energy per unit area of laser light in the lateral crystal part.)

In the present specification, "EP-EA" is defined as having EP / EA or EA / EP in the range of 0.95 to 1.05. Similarly, "IL # IA" defines that IL / IA or IA / IL is in the range of 0.95 to 1.05.

In this specification, the "irradiation energy" or "irradiation intensity" of laser light is calculated | required from the light quantity of the laser light irradiated to the film surface of a annealed semiconductor film, and is the light energy or light intensity before subtracting the loss in the film surface by Fresnel reflection. to be.

When the said annealed semiconductor film is an amorphous silicon film, it is preferable to set on the laser beam irradiation conditions which satisfy | fill following formula (3) and (4).

0.82? EP / EA? (3),

EL / EA? 0.70... (4)

The "silicone film" is a film mainly containing silicon. In this specification, a "main component" is defined as a component of content of 50 mass% or more. In the silicon film for TFT, 90 mass% or more of silicon content is preferable.

In the laser annealing apparatus of the present invention, it is preferable that the absorption of the laser light in the lateral crystal portion is set to a laser light irradiation condition smaller than the absorption of the laser light in the granular crystal portion.

In the laser annealing apparatus of the present invention, the laser light is preferably a continuous oscillation laser light.

In the laser annealing apparatus of the present invention, the laser light oscillation source is preferably a semiconductor laser. The laser light oscillation source is preferably a semiconductor laser having an oscillation wavelength in the wavelength region of 350 to 600 nm, and more preferably a semiconductor laser having an oscillation wavelength in the wavelength region of 350 to 500 nm. The laser light oscillation source is more preferably a GaN semiconductor laser or a ZnO semiconductor laser.

In the laser annealing apparatus of the present invention, when the annealing region is shifted with respect to the annealed semiconductor film and the laser annealing is performed again, the region to which the laser light is irradiated and the region to which the laser light is irradiated are partially overlapped. Preferably, the laser annealing is performed.

In the laser annealing apparatus of the present invention, it is preferable that relative scanning means for relatively scanning the laser light is provided while partially irradiating the laser light to the annealed semiconductor film.

In the laser annealing apparatus of the present invention, as the laser light irradiation conditions changed in the granular crystal portion and the amorphous portion, the laser light irradiation intensity per unit area or the laser light irradiation intensity per unit area and irradiation time per unit area are given. Can be mentioned.

In the laser annealing apparatus of the present invention, laser light irradiation time per unit area may be mentioned as other laser light irradiation conditions that are changed in the granular crystal portion and the amorphous portion.

In such a configuration, when the relative scanning means is provided, the laser light is simultaneously applied to an area including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the amorphous crystals remaining uncrystallized. It is preferable to have a beam pattern which can be irradiated and has a larger total irradiation width in the relative scanning direction of the granular crystal portion than the total irradiation width in the relative scanning direction of the amorphous portion.

The beam pattern may consist of a plurality of patterns spaced apart in the relative scanning direction of the laser light. In this case, the "total irradiation width in the relative scanning direction" is defined as the sum of the irradiation widths of the plural patterns spaced apart in the relative scanning direction of the laser light.

The laser light can be irradiated simultaneously to a region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the amorphous crystals remaining uncrystallized, and also viewed in the relative scanning direction of the laser light. The front and rear ends are positioned substantially in front of the first beam pattern as viewed in the relative scanning direction of the laser beam and the first beam pattern substantially perpendicular to the relative scanning direction of the laser light, and the granular crystal part It is preferable to have the shape which matched the 2nd beam pattern which can irradiate, and at least the irradiation energy distribution of the said 1st beam pattern part is substantially uniform.

Here, it is referred to as a beam pattern of a shape in which the first beam pattern and the second beam pattern are matched, and a beam pattern of a shape in which the first beam pattern and the second beam pattern are matched with one beam may be formed. You may form the beam pattern of the shape which matched the 1st beam pattern and the 2nd beam pattern. Moreover, the beam pattern which the 1st beam pattern and the 2nd beam pattern contacted may be sufficient, and the beam pattern which these spaced apart may be sufficient.

In the laser annealing apparatus of the present invention, other laser light irradiation conditions that are changed in the granular crystal portion and the amorphous portion include the wavelength of the laser light. In this configuration, when the place to be irradiated is not specified, the laser light shall mean all of the laser lights of a plurality of wavelengths to be used.

In such a configuration, in the case where the relative scanning means is provided, at least a part of the granular crystals generated outside the lateral crystal with respect to the annealed semiconductor film and the amorphous crystals remain uncrystallized as a preferable form of the irradiated laser beam. The region including at least a portion of the laser beam can be irradiated at the same time, and the front side and the rear end side have a beam pattern that is substantially perpendicular to the relative scanning direction and is substantially linear with respect to the relative scanning direction, and the granular crystal And a laser beam having a wavelength distribution characteristic in which the laser light having a shorter wavelength than the wavelength of the laser light of the beam portion for irradiating the amorphous portion is included in the beam portion for irradiating the portion.

Here, it is said that the beam shape is thin and long substantially rectangular shape, and the wavelength of the beam part which irradiates a granular crystal part in a substantially rectangular beam has a wavelength distribution shorter than the wavelength of the beam part which irradiates an amorphous part, In the granular crystal part, beams of a plurality of wavelengths may overlap. When using the laser beam which has such a beam characteristic, a laser annealing may be performed by carrying out a relative scan or you may carry out without performing a relative scan.

In addition, as another preferred form of the laser beam to be irradiated, simultaneously irradiating a region including at least a portion of the granular crystals generated outside of the lateral crystal with respect to the annealed semiconductor film and at least a portion of the amorphous crystals remaining uncrystallized A first laser beam having a beam pattern in which the front end side and the rear end side are substantially perpendicular to the relative scanning direction and are substantially linear in the laser beam scanning direction, and the wavelength distribution is substantially uniform; The light source is located in front of the first laser beam as viewed in the relative scanning direction of light, and the granular crystal portion can be irradiated, and the second laser beam having a shorter wavelength than the first laser beam can be simultaneously irradiated. The 1st laser beam and the 2nd laser beam which irradiate simultaneously may be in contact with the film surface of the said annealed semiconductor film, and may overlap partially.

The semiconductor film of the present invention is produced by performing the laser annealing method of the present invention on a annealed semiconductor film made of an amorphous semiconductor.

The semiconductor film of the present invention may be either before patterning or after patterning. According to the present invention, it is possible to provide a semiconductor film whose overall surface is composed of lateral crystals.

According to the laser annealing method of the present invention, the whole surface lateral crystallization without the granular crystal part is basically possible, but since the granular crystal produced at the start and end of the laser annealing is not subjected to the second laser annealing, The winning decision of this part remains. Looking at the whole substrate, the amount of this granular crystal is a little.

The term "semiconductor film is made up of substantially whole-surface lateral crystals" means that at the beginning and the end of laser annealing, all parts except the granular crystals remaining without the second laser annealing are made of lateral crystals.

The semiconductor device of this invention was equipped with the active layer obtained using the semiconductor film of the said invention, It is characterized by the above-mentioned. Examples of the semiconductor device of the present invention include a thin film transistor (TFT).

The electro-optical device of the present invention includes the semiconductor device of the present invention. As an electro-optical device, an electroluminescent (EL) device, a liquid crystal device, an electrophoretic display device, a sheet computer provided with these, etc. are mentioned.

EFFECTS OF THE INVENTION [

The laser annealing method of the present invention is configured to perform laser annealing under conditions in which the granular crystal portion and the amorphous portion of the pyrianneal semiconductor film made of the amorphous semiconductor are fused and the lateral crystal portion of the annealed semiconductor film is not fused.

Further, in the laser annealing method of the present invention, the laser light irradiation conditions in the granular crystal portion are changed from the laser light irradiation conditions in the amorphous portion so as to satisfy the following formula (1), preferably the following formula (1A). It is set as the structure which anneals.

EA-EP | <| EA-EPs |. (One),

EP ≒ EA. (1A)

(In formulas (1) and (1A),

EA is the absorbed light energy per unit area of laser light in the amorphous portion,

EPs is the absorbed light energy per unit area of the laser light in the granular crystal part when the laser light is irradiated under the same laser light irradiation conditions as the amorphous part,

EP represents the actual absorbed light energy per unit area of laser light in the granular crystal part, respectively.)

Examples of laser light irradiation conditions to be changed in the granular crystal part and the amorphous part include laser light irradiation intensity per unit area, laser light irradiation intensity per unit area and irradiation time per unit area, irradiation time per unit area, and wavelength of laser light.

According to the laser annealing method of the present invention, the granular crystal portion and the amorphous portion can be selectively melted for high crystallization. Moreover, since the lateral crystal part once produced is made into the condition which does not melt | dissolve, there is no possibility that the lateral crystal part which grew hardly remelts and the crystallinity will change.

In addition, under conditions where the granular crystal part and the amorphous part of the annealed semiconductor film are not melted and the lateral crystal part of the annealed semiconductor film is not melted, there is a slight difference in the absorption ratio of the laser light in the granular crystal part and the amorphous part. Under laser light irradiation conditions, there is a slight difference in the absorbed light energy per unit area in the granular crystal part and the amorphous part. In this invention, the laser light irradiation conditions in a granular crystal part and an amorphous part are changed, and it is comprised so that the difference of the absorbed light energy per unit area in a granular crystal part and an amorphous part may become small. Therefore, compared with the case where the granular crystal portion and the amorphous portion are treated under the same laser light irradiation conditions, the temperature gradient between the granular crystal portion and the amorphous portion can be made smaller to grow the lateral crystals more uniformly on the entire surface of the film.

According to the laser annealing method of the present invention, it is possible to make the amorphous semiconductor film highly crystallized on the whole surface, and the amorphous semiconductor film can be made into a lateral crystal film having almost no granular crystal parts on the entire surface and seamless. The present inventors actually realize a lateral crystalline film having a substantially entire surface seamless (see SEM / TEM surface photograph (FIG. 28) of Example 1 later).

By using the laser annealing method of the present invention, a semiconductor film having high crystallinity and uniformity and suitable as an active layer of a thin film transistor (TFT) or the like can be produced at low cost. By using this semiconductor film, semiconductor devices, such as TFT which are excellent in element characteristic (carrier mobility etc.) and element uniformity, can be manufactured.

In the present invention, a substantially crystalline crystal film having almost no granular crystal parts and a seamless crystalline crystal film can be produced. Therefore, the beam end of the laser light and the semiconductor such as the TFT are based on the design information of the formation position of the semiconductor device such as the TFT. It is unnecessary to devise a device such as scanning laser light that does not overlap the device forming regions of the device, or selectively irradiating laser light only to the device forming regions of a semiconductor device such as a TFT, and thus device characteristics (carrier mobility, etc.) and device uniformity. A semiconductor device such as TFT having excellent properties can be stably manufactured at low cost. An electro-optical device including such a semiconductor device as TFT is excellent in performance such as display quality.

`` Laser annealing method ''

Conventionally, it has been known that amorphous silicon (a-Si) and polycrystalline silicon (poly-Si) have different absorption characteristics with respect to the wavelength of laser light. However, conventionally, granular crystalline silicon and lateral crystalline silicon are both polycrystalline silicon (poly-Si), and it is not considered that there is a difference in the absorption characteristics of these laser lights.

MEANS TO SOLVE THE PROBLEM This inventor evaluated the absorption characteristics with respect to the wavelength of a laser beam about granular crystalline silicon and lateral crystalline silicon, and found out that there exists a difference in these absorption characteristics. By focusing on these absorption characteristics, it has been found that laser annealing can be performed under conditions in which the granular crystal portion and the amorphous portion are not melted and the lateral crystal portion is not melted. The present inventors can laterally crystallize them by selectively melting only the granular crystal parts and the amorphous parts without remelting the crystalline crystals once generated by performing laser annealing under such conditions, without changing their crystallinity. We found out what we can do with a cotton lateral decision. EMBODIMENT OF THE INVENTION Hereinafter, the evaluation which this inventor performed is demonstrated.

Using an GaN semiconductor laser (oscillation wavelength 405 nm), laser annealing was performed by continuously irradiating an elongated rectangular laser light L with respect to the amorphous silicon (a-Si) film. The substrate plane is the xy plane, the main relative scanning direction of the laser light is the x direction, and the negative relative scanning direction is the y direction.

As shown in Fig. 1 (a), when the x-direction relative scanning of the laser light L is performed once at a predetermined y position, the lateral growth of the lateral growth extending in the main relative scanning direction x of the laser light L is shown. Crystals are generated, and granular crystals (granular poly-Si) having small grains are generated outside the region of the lateral crystal generation. After this one-time relative scan of the laser light L, granular crystals are generated on both sides with a region of lateral crystal growth extending in a band shape.

Here, the case where a granular crystal is produced in the end part in the area | region to which the laser beam L is directly irradiated is shown. Depending on the laser annealing conditions, an end portion in the area where the laser light L is directly irradiated, and / or the area where the laser light L is not directly irradiated but conducts heat (= area where the laser light L is directly irradiated) Granular crystals are produced in the region immediately outside).

In addition, in this specification, when growing a lateral crystal by carrying out the relative scan of a laser beam, the area | region annealed when performing the x direction relative scan of the laser light L once at a predetermined y position is referred to as "one laser annealing. Annealing region ”.

In order to process the whole film | membrane, as shown to FIG. 1 (b), the y direction is changed and the x direction relative scan of the laser beam L is repeated. When carrying out the x-direction relative scanning of the laser light L by changing the y position, the region including at least a part of the granular crystals generated outside the lateral crystal and at least a part of the non-crystallization remaining uncrystallized before the y position is changed. Laser annealing is performed. At this time, the laser light L may be irradiated to the lateral crystal generated earlier.

As shown in the figure, when performing the relative scanning in the x direction of the laser light L by changing the y position (when changing the annealing area), the area where the laser light L is irradiated to the annealed semiconductor film first and then It is preferable to perform laser annealing so that the area | region to which the laser beam L is irradiated partially overlaps.

In Fig. 1A, reference numeral 20 is attached to the annealed semiconductor film, reference numeral 110 is attached to the substrate stage, and reference numeral 120 is attached to the laser head. Fig.1 (a) is a figure in the middle of carrying out the x direction relative scan of the laser beam L once at the predetermined y position. Here, the size of the laser head is shown large with respect to the film for easy visual confirmation.

Fig. 1 (b) is an image plan view of crystallization when the x-direction relative scanning of the laser light L is repeated by changing the y position. In the figure, the area | region where the hatching is not especially attached among the area | region to which the laser beam L was irradiated is the generation | occurrence | production area | region of a lateral crystal.

For the lateral crystalline part (lateral crystalline poly-Si), the granular crystalline part (particulate poly-Si), and the amorphous part (a-Si), the complex refractive index (n + ik) is changed with an ellipsometer by changing the wavelength of the measured light. (k is an extinction coefficient and ik represents an imaginary part.) The relationship between the wavelength and refractive index n in each crystal state is shown in FIG. Moreover, the relationship between the wavelength and absorption coefficient (alpha) in each crystal state was calculated | required based on the following formula. The results are shown in Fig. In both crystal states, it became clear that the absorption coefficient tended to greatly decrease in the vicinity of 400 nm.

Absorption coefficient (α) = k / 4πλ

Where k is the extinction coefficient and λ is the wavelength.

Next, the absorptivity of the silicon film in each wavelength was calculated | required about lateral crystalline silicon, granular crystalline silicon, and amorphous silicon.

The emission energy from the laser head is attenuated and absorbed by the film by the loss caused during transmission through various optical systems provided in the laser annealing device and by the Fresnel reflection on the film surface. The light energy absorbed by the film is represented by the following formula.

(Light energy absorbed by the film) = (light energy irradiated on the film) x (ratio of the amount of light incident on the film without reflecting the surface) x (ratio of the amount of light absorbed by the film)

In the above formula, the ratio of the amount of light incident on the film without reflecting the surface is the ratio of the amount of light absorbed on the film. Absorption rate is a ratio of the light quantity absorbed by a film with respect to the light quantity of the laser beam irradiated to a film | membrane, and it is represented by absorption ratio = axb.

In said formula, a is a ratio of the light quantity absorbed by a film | membrane, and is calculated | required by the following formula. The film thickness t was set to 50 nm which is common when crystallization is performed by laser annealing to form a polysilicon TFT.

a = exp ^-αt

Where α is the absorption coefficient and t is the film thickness

B is a ratio of the quantity of light which injects into a film | membrane, without surface reflection, and is calculated | required from the following formula. b is an amount calculated | required by subtracting the loss in the film surface by Fresnel reflection from the light quantity of the laser beam radiate | emitted from the laser head.

b = 1-((1-n) / (1 + n)) ²

Where n is the refractive index.

Further, the absorption ratio of granular crystalline silicon to the absorption of amorphous silicon at each wavelength (= absorption of granular poly-Si / absorption of a-Si), and the ratio of absorption of lateral crystalline silicon to absorption of amorphous silicon (= lateral) water absorption of poly-Si / water absorption of a-Si). These water absorptivity ratios are the relative absorptivity of granular crystalline silicon and the relative absorptivity of lateral crystalline silicon when the absorptivity of amorphous silicon is set to one. The results are shown in Fig.

Granular crystalline silicon and lateral crystalline silicon are both polycrystalline silicon (poly-Si), but Fig. 4 shows that the absorption characteristics of these laser lights with respect to the wavelength of the laser light differ greatly.

As shown in Fig. 2 to Fig. 4, it has become clear that granular crystalline silicon (granular poly-Si) having a small particle diameter exhibits intermediate characteristics between amorphous silicon (a-Si) and lateral crystalline silicon (lateral poly-Si). . Thus, the example which evaluated absorption characteristics by dividing lateral crystalline silicon and granular crystalline silicon was not outstanding in the past.

As shown in Fig. 4, in the wavelength range of less than 350 nm, there is no significant difference in the absorption characteristics of the granular crystalline silicon and the lateral crystalline silicon, and it is evident that all of them exhibit a high absorption rate of about 0.7 to 0.9 times the absorption rate of the amorphous silicon. On the other hand, in the wavelength region of 350 nm or more, the absorption ratio for amorphous silicon tends to decrease as both the grain crystalline silicon and the lateral crystal silicon become long wavelengths, but the level of the decrease in the absorption ratio for amorphous silicon is higher in the lateral crystal silicon. It has become clear that the larger and lowering occurs on the shorter wavelength side. In the wavelength region of 350 to 650 nm, the difference between the ratio of absorption of granular crystalline silicon to amorphous silicon and the ratio of absorption of lateral crystalline silicon to amorphous silicon is large.

Although FIG. 4 shows relative absorptivity ratios based on the absorptivity of amorphous silicon (a-Si), as shown in FIG. 3, in terms of absolute absorptivity, lateral crystalline silicon and granular crystalline silicon are observed in a wavelength region of 50 nm or more. , And all of the absorption rates of amorphous silicon are remarkably small. Therefore, it is preferable to determine the wavelength of the laser beam used within the range where the absorption rate of lateral crystalline silicon and the absorption rate of granular crystalline silicon are large, and the absorption rates of granular crystalline silicon and amorphous silicon are somewhat high.

The absorption rate of the laser light is changed by the film thickness t of the silicon film. The relationship between the wavelength of the laser light when the film thickness (t) (nm) = 50, 100, 200 and the absorption ratio of the lateral crystalline silicon to the absorption rate of the amorphous silicon (= absorption rate of lateral poly-Si / absorption rate of a-Si) was obtained. . The results are shown in Fig. Similarly, the absorption ratio of granular crystalline silicon (= absorption rate of granular poly-Si / absorption rate of a-Si) to the absorption rate of amorphous silicon is also changed by the film thickness (not shown).

When the polysilicon TFT is formed by crystallization by laser annealing, at the film thickness t (nm)> 120, the element formation of the TFT becomes difficult and the leakage current increases, and the film thickness t (nm) <40 In this case, the film thickness of the active layer is too thin, which lowers the reliability of the device. Therefore, for the TFT, 40? Film thickness t (nm)? 120 nm is preferable. As for the film thickness t of the amorphous silicon film in the case of crystallizing by laser annealing to form a polysilicon TFT, about 50 nm is most common.

Under conditions of 40? Film thickness (t) (nm)? 120 nm, in order to increase the difference between the absorption rate of the lateral crystalline silicon and the absorption rate of the granular crystalline silicon, and to increase the absorption rate of the granular crystalline silicon and the amorphous silicon to some extent, 350 It is preferable to use the laser light of the wavelength range of -600 nm, and it is more preferable to use the laser light of the wavelength range of 350-500 nm.

Since the excimer laser light generally used for laser annealing is ultraviolet laser light having a wavelength of 300 nm or less, both the lateral crystal part, the granular crystal part, and the amorphous part have high absorption and no significant difference in absorption characteristics.

In addition, the visible laser light used by patent documents 1-5 mentioned in the item of "background art" is laser light of 500-550 nm wavelength range, such as 2nd harmonics of a solid state laser. In this wavelength region, although there appears to be a large difference in the absorption characteristics of the lateral crystal portion and the granular crystal portion in FIG. 4, as shown in FIG. 3, since the absorption rate of the amorphous portion itself is small, the absorption of the lateral crystal portion and the granular crystal portion is actually performed. There is no big difference in the characteristics.

That is, laser light of 300 nm or less wavelength region or 500-550 nm wavelength region which conventionally has no big difference in the absorption characteristic of a lateral crystal part and a granular crystal part is used. And since both the lateral crystal part and the granular crystal part are polycrystalline silicon, it was thought that there is no big difference in absorption characteristic. The present inventor has made clear for the first time that there exists a wavelength range which shows a big difference in the absorption characteristic of a lateral crystal part and a granular crystal part.

Japanese Laid-Open Patent Publication No. 2004-64066 discloses a laser annealing apparatus using a GaN semiconductor laser (wavelength 350-450 nm). As irradiation conditions, the scanning speed 3000mm / s and the optical power density 600mJ / cm <2> on an amorphous silicon film surface are mentioned (paragraph 0227). However, this document does not examine the relationship between crystal state and water absorption.

The melting point of single crystal silicon (c-Si) is about 1400 ° C, and the melting point of amorphous silicon (a-Si) is about 1200 ° C. Therefore, in order to fuse a granular crystal part and an amorphous part, it is preferable that the surface arrival temperature of the laser beam in a granular crystal part and an amorphous part is about 1400 degreeC or more.

The inventors use an GaN semiconductor laser (oscillation wavelength 405 nm) to perform laser annealing on an amorphous silicon film by changing the amount of emitted light from the laser head under conditions of a relative scanning speed of 0.01 m / s or more. It was about 1700 degreeC when the surface arrival temperature of the laser beam required for lateral crystal growth was calculated | required by SEM and TEM whether the lateral crystal actually grows in a part. In addition, it was found from the actual experiment that partial peeling of the film may occur due to ablation when the surface reach temperature of the laser light is about 2200 ° C. or more. That is, in order to lateral crystallize the granular crystal part and the amorphous part, it is preferable that the surface arrival temperature of the laser light in these parts is about 1700-2200 degreeC. The surface attainment temperature of the laser light is the instantaneous film surface temperature when the laser light is irradiated.

The surface attainment temperature is the amount of light incident on the silicon film (the amount of light is lost from the amount of light emitted from the laser head while passing through various optical systems provided in the laser annealing device, and the amount of light due to Fresnel reflection on the film surface). And theoretically obtained from the water absorption of the silicon film.

The irradiation energy required to bring the surface attainment temperature of the laser light to a desired temperature is conceptually represented by the following equation. In addition, each energy is not simply expressed because it changes with time and temperature, but is conceptually shown here. The melting energy (E2) is the energy required at the melting point.

(Irradiation energy (E1)) = (melting energy (E2)) + (energy required to raise to the desired temperature (E3)) + (heat dissipation energy (E4))

For reference, a calculation example in the adiabatic model when the rectangular parallelepiped of 1 μm × 1 μm × 50 nm is heated is shown. The desired temperature is calculated here on the conditions of 1400 degreeC.

The melting energy (E2) required for melting the Si contained in the volume of 1 μm × 1 μm × 50 nm is calculated as follows.

E2 = (unit melting energy) x (number of moles of Si contained in a volume of 1 µm × 1 µm × 50 nm) = 46 × 10 ³ × ((2.32 g / cm 3) × (10 ⁻⁶ × 10 ⁻⁶ × ⁵ O) × 10 ^-9 m3) / 28) = 1.9 × 10 ^-10 J

The energy (E3) required in order to raise Si contained in the volume of 1 micrometer x 1 micrometer x 50 nm to desired temperature (1400 degreeC = melting | fusing point in this calculation example) is computed as follows.

E3 = (specific heat) × (mass of Si contained in a volume of 1 µm × 1 µm × 50 nm) × (desired temperature) = 770 J / kgK × (2.32 g / cm 3 × (10 ^-6 × 10 ^-6 × 50 × 10 ^-9 ㎥)) × 1400 ° C = 1.3 × 10 ^-10 J

6 shows the relationship between the energy ratio with respect to the absorbed light energy at which the surface reach temperature of the laser light becomes 2200 ° C. and the surface reach temperature of the laser light. Although amorphous silicon melts at about 1200 degreeC or more, in this figure, the area | region below about surface temperature of about 1400 degreeC in which lateral crystal and a grain crystal do not melt is shown as "non-fusion". Moreover, the area | region of about 1700-2200 degreeC of the surface arrival temperature of the laser beam in which a lateral crystal grows, and the area | region which is about 2200 degreeC or more of the surface arrival temperature of the laser beam which partial peeling of a film | membrane generate | occur | produces by ablation.

When light of uniform light energy distribution is irradiated to the annealed semiconductor film 20, since the amount of light energy absorbed changes according to a crystal state, the surface arrival temperature of the laser beam in each crystal state changes. Fig. 6 shows that the lateral crystal growth is possible under an energy ratio of 0.82 or more to the absorbed light energy at which the surface arrival temperature of the laser light reaches 2200 ° C., and the granular crystals do not melt under the conditions where the copper energy ratio is 0.70 or less.

Absorption light in which the surface attainment temperature of the laser light is about 1700-2200 ° C for the granular crystal part and the amorphous part so that the granular crystal part and the amorphous part can be melted to form lateral crystallization and the already generated lateral crystal part is not fused. Energy is given to the lateral crystal portion, and the absorbed light energy at which the surface reach temperature of the laser light is about 1400 ° C. or less may be given. That is, when the annealed semiconductor film is an amorphous silicon film, laser annealing may be performed under the conditions satisfying the following formulas (3) and (4).

0.82? EP / EA? (3),

EL / EA? 0.70... (4)

(In formulas (3) and (4),

EA is the absorbed light energy per unit area of laser light in the amorphous portion,

EP is the absorbed light energy per unit area of laser light in the granular crystal part.

EL represents absorbed light energy per unit area of laser light in the lateral crystal part.)

In order to stably perform laser annealing in which the granular crystal part and the amorphous part are lateral crystallized and the lateral crystal is not fused, it is more preferable to perform laser annealing under the conditions satisfying the following formulas (3A) and (4).

0.85 ≦ EP / EA ≦ 1.0... (3A),

EL / EA? 0.70... (4)

In order to lateral crystallize the granular crystal part and the amorphous part, it has been described that the surface attainment temperature of the laser light in these parts needs to be about 1700-2200 ° C. As a result of performing the laser annealing by changing the conditions within the range of the said surface reach | attainment temperature, this inventor has made granular crystals become the core in comparatively low surface arrival temperature conditions within the said range, and critiques about the main relative scanning direction of a laser beam. The curved lateral crystals are intended to grow in the row direction (for example, an angular direction of 5 to 45 ° with respect to the main relative scanning direction of the laser light), and the lateral crystals are intended to grow so that they are aligned at the same time in the main relative scanning direction. It was produced. In order to suppress the variation in the device characteristics of the TFT, it is preferable that the lateral crystal directions are substantially aligned in approximately the entire surface of the film.

MEANS TO SOLVE THE PROBLEM This inventor melt | dissolves a granular crystal instantaneously by performing laser annealing on the conditions that the surface reach | attainment temperature of the laser beam in a granular crystal part and an amorphous part will be about 2000 +/- 200 degreeC, and the lateral crystal growth which makes a granular crystal the core is suppressed. It was found that the orientation of the lateral crystals could be aligned in approximately the entire surface of the film. The present inventors have found that by performing laser annealing under such conditions, the angle formed between the main relative scanning direction of the laser light and the lateral crystal growth direction can be aligned to 5 ° or less in approximately the entire surface of the film.

Fig. 7 shows a range of absorption power density at which the surface attainment temperature in the amorphous portion is about 2000 ± 200 ° C. with respect to the relative scanning speed of the laser light. As shown in this figure, the conditions under which the absorption power density P (MW / cm 2) of the laser light and the relative scanning speed v (m / s) of the laser light in the amorphous portion satisfy the following formula (5). It is preferable to perform laser annealing at.

0.44v ^0.34143 ? P? 0.56v ^0.34143 ... (5)

Conventionally, in the research in the field of SOI, it is reported that the crystal growth rate of Si of 1 cm / s or less is represented by the following formula. V = V0 × exp (-Ea / kT)

Where V is the solid phase growth rate (cm / s) from a-Si to Poly-Si. K is the Boltzmann constant. T is the annealing temperature (K). V0 is the coefficient and V0 = 2.3 ~ 3.1 x 10 ⁸ cm / s Ea is the activation energy (same as the hollow formation energy in = c-S1), and Ea = 2.68-2.71 eV.)

The present inventors confirmed that the lateral crystal growth rate in the laser annealing of the present invention is also represented by the above relational expression. As mentioned above, since annealing temperature in an amorphous part is about 2200 degreeC an upper limit, the upper limit of a lateral crystal growth rate becomes 8 m / s.

Referring to FIG. 4, there was described a large difference in absorption characteristics between the lateral crystal and the granular crystal in the wavelength region of 350 nm or more. 4 shows that there is a difference in absorption characteristics between the granular crystal and the amorphous in the wavelength region of 350 nm or more. Therefore, when the laser light is irradiated to the granular crystal part and the amorphous part to be melted under the same conditions, the amount of light energy absorbed varies depending on the crystal state, so that the temperature at which the surface of the laser light is reached in the granular crystal part and the amorphous part is changed. do. This form is shown in FIG.

8 is irradiated with laser light of 405 nm to the lateral crystal part, the granular crystal part, and the amorphous part under the same irradiation conditions, and the surface attainment temperature of the granular crystal part and the amorphous part is about 1700 to 2200 ° C. When the laser annealing is carried out so that the surface attainment temperature of the lateral crystal part becomes about 1400 degrees C or less,

It is an image figure of the absorption distribution in the amorphous part, the granular crystal part, and the lateral crystal part, distribution of the laser light irradiation intensity per unit area on a film surface, distribution of the absorption energy per unit area of laser light, and temperature distribution.

In this figure, the temperature distribution of the film is shown, not the surface attainment temperature of the laser light. This figure shows the surface of the film to be annealed during laser annealing, the position of the laser beam on the surface, and the relative scanning direction of the laser beam.

Although the irradiation light intensity distribution of the laser light of the film surface in an amorphous part, a granular crystal part, and a lateral crystal part is uniform, since each absorption rate differs, the absorption light energy per unit area of the laser light in each part differs.

Under the above conditions, the granular crystal portion and the amorphous portion become a temperature at which they melt, but the generated lateral crystal portion is suppressed to a temperature which does not re-melt even after being irradiated with laser light.

Here, when the attention is paid to the granular crystal part and the amorphous part which are all melted, there is a slight difference in the absorption rate of the laser light in these parts. Therefore, the absorbed light energy per unit area in the granular crystal part and the amorphous part is the same under the same laser light irradiation conditions. There is some tea in it. As a result, a slight temperature difference occurs between the granular crystal part and the amorphous part. Moreover, the temperature gradient resulting from this temperature difference arises in the boundary of the granular crystal part and an amorphous part, and its vicinity.

The temperature difference between the granular crystal part and the amorphous crystal part is much smaller than the temperature difference between the lateral crystal part and the granular crystal part. However, the temperature gradient between the granular crystal portion and the amorphous portion (this temperature gradient is a temperature gradient in the y direction (negative relative scanning direction)) is slightly lower in lateral crystal growth in the transverse direction (x direction, main relative scanning direction). There is a risk of influence. The absence of a temperature gradient between the granular crystal part and the amorphous part is preferable because the lateral crystals can be grown more uniformly on the entire surface of the film.

Therefore, in the present invention, the laser annealing is performed by changing the laser light irradiation conditions in the granular crystal portion from the laser light irradiation conditions in the amorphous portion so as to satisfy the following formula (1), preferably the following formula (1A). .

EA-EP | <| EA-EPs |. (One),

EP ≒ EA. (1A)

(In formulas (1) and (1A),

EA is the absorbed light energy per unit area of laser light in the amorphous portion,

EPs is the absorbed light energy per unit area of the laser light in the granular crystal part when the laser light is irradiated under the same laser light irradiation conditions as the amorphous part,

EP represents the actual absorbed light energy per unit area of laser light in the granular crystal part, respectively.)

That is, in the present invention, laser annealing is performed such that the difference in absorption light energy per unit area between the granular crystal portion and the amorphous portion is reduced by changing the laser light irradiation conditions in the granular crystal portion and the amorphous portion. In such a configuration, the lateral crystals can be grown more uniformly on the entire surface of the film by reducing the temperature gradient between the granular crystal portions and the amorphous portions as compared with the case where the granular crystal portions and the amorphous portions are treated under the same laser light irradiation conditions.

The irradiation light energy IL per unit area of laser light in the lateral crystal portion preferably satisfies the following formula (2A) or (2B).

IL ≒ IA. (2A),

IL <IA. (2B)

(In formulas (2A) and (2B),

IA is the irradiation light energy per unit area of laser light in the amorphous portion,

IL represents the irradiation light energy per unit area of laser light in the lateral crystal part.)

As laser beam irradiation conditions which change in a granular crystal part and an amorphous part, the laser beam irradiation intensity per unit area is mentioned.

Since the difference in absorption between the granular crystal portion and the amorphous portion can be seen from FIG. 4, the laser light irradiation intensity per unit area in the granular crystal portion may be slightly increased to satisfy the relationship of IP> IA according to the difference in absorption ratio. Here, IA is irradiation light energy per unit area of laser light in the amorphous portion, and IP is irradiation light energy per unit area of laser light in the granular crystal portion.

For example, if the absorption rate of the amorphous portion: the absorption rate of the granular crystal portion = 100: 90, that is, if the absorption rate of the granular crystal portion is 10% lower than that of the amorphous portion, the laser light irradiation intensity per unit area in the granular crystal portion Is increased by 10% of the laser light irradiation intensity per unit area in the amorphous portion, the EP ≒ EA. (1A) can be satisfied.

Fig. 9 shows the change in the laser light irradiation intensity per unit area in the granular crystal part and the amorphous part. It is an image figure at the time of satisfying (1A). This example is an example where the laser light irradiation intensity per unit area in the lateral crystal part and the amorphous part is set to be substantially equal to IL # IA.

Here, the laser light irradiation intensity per unit area of the granular crystal part is slightly higher than the laser light irradiation intensity per unit area in the amorphous part to satisfy the above formula (1A). On the contrary, the laser light irradiation intensity per unit area on the amorphous part side. The above formula (1A) can be satisfied even if the configuration is reduced a little. However, in consideration of the effective use of the amount of light and the like, a configuration in which the laser light irradiation intensity per unit area on the granular crystal portion side is slightly increased is preferable.

Similarly, the laser light irradiation intensity per unit area in the granular crystal portion and the amorphous portion is changed, and EP ≒ EA. It is an image figure at the time of satisfying (1A). This example is an example in which the laser light irradiation intensity per unit area in the lateral crystal portion is also changed to IL < IA.

The laser light irradiation conditions to be changed in the granular crystal part and the amorphous part may be laser light irradiation intensity per unit area and laser light irradiation time per unit area. The laser light irradiation time per unit area in the granular crystal part is made longer than the laser light irradiation time per unit area in the amorphous part and lateral crystal part by making the width of the main relative scanning direction of the laser beam in the said part larger. Can be.

Fig. 11 shows the change in the laser light irradiation intensity per unit area and irradiation time per unit area in the granular crystal part and the amorphous part, and the EP ≒ EA. It is an image figure at the time of satisfying (1A). This example is an example in which the laser light irradiation intensity per unit area in the lateral crystal portion is also changed to IL < IA. IL X IA may be sufficient.

The laser light irradiation conditions to be changed in the granular crystal portion and the amorphous portion may be laser light irradiation time per unit area. The laser light irradiation time per unit area in the granular crystal part is made longer than the laser light irradiation time per unit area in the amorphous part and lateral crystal part by making the width of the main relative scanning direction of the laser beam in the said part larger. Can be.

In such a configuration, in order to set the irradiation light energy per unit area satisfying the above (2A) or (2B), the irradiation time of the laser light per unit area in the lateral crystal portion is the laser light per unit area in the amorphous portion. It is preferable to make it equal to or less than irradiation time.

Similarly to the case where the laser light irradiation intensity is changed as the laser light irradiation condition, the laser light irradiation time per unit area in the granular crystal part may be lengthened in accordance with the difference in absorbance read from FIG. 4.

When performing laser annealing by carrying out the relative scan of the laser light, the laser light irradiation time per unit area of each crystal region can be adjusted by the beam pattern of the laser light L. FIG. As described above, in order to perform laser annealing by making the laser light irradiation time in the granular crystal portion longer than the laser light irradiation time in the amorphous portion, the beam pattern of the laser light L is generated outside the lateral crystal. Irradiation of the granular crystal portion can be simultaneously irradiated with respect to a region including at least a portion of the granular crystal and at least a portion of the non-crystallized remaining crystallization, and also compared with the total irradiation width Da in the relative scanning direction of the amorphous portion. It is preferable that the total radiation width Dp in the direction is a wide beam pattern (see Figs. 12 (a) and (b)).

In order to achieve the above-described beam pattern, the laser light L can be irradiated simultaneously with a region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the non-crystallized amorphous crystals, In addition, the relative scanning direction of the laser beam L and the first beam pattern Lp1 and the laser beam L are substantially perpendicular and substantially linear with respect to the relative scanning direction of the laser light L as viewed in the relative scanning direction. Irradiating at least the first beam pattern Lp1 portion having a beam pattern that is positioned in front of the first beam pattern Lp1 and viewed in the direction and is aligned with the second beam pattern Lp2 capable of irradiating the granular crystal portion. It is preferable to use the laser light L whose energy distribution is substantially uniform.

As shown in the figure, the second beam pattern Lp2 is preferably a pattern capable of irradiating only the granular crystal portions. However, the second beam pattern Lp2 may be a pattern capable of irradiating not only the granular crystal part but also its surroundings within a range where an effect of improving the temperature gradient between the granular crystal part and the amorphous part is obtained.

In the above configuration, first, the granular crystal part is annealed first only by the second beam pattern Lp2, and then, first, the irradiation energy distribution and the beam width are substantially uniform, and the rear end side is a straight line which is substantially perpendicular to the relative scanning direction. Since the whole area irradiated simultaneously by the beam pattern Lp1 is annealed, the end of laser light irradiation can be made substantially the same in any crystal region. When the end time of laser light irradiation differs from region to region, the annealing of the regions on both sides is considerably affected by the cooling which starts approximately at the same time as the end of irradiation. In order to obtain a better and more uniform lateral crystal, as described above, it is preferable that the laser light irradiation is terminated at the same time.

In the beam pattern, as shown in FIGS. 12A and 12B, the first beam pattern Lp1 and the second beam pattern Lp2 may be in contact with each other or may be spaced apart from each other. During this time, the cooling distance is not so small, so the distance between them is shorter. Therefore, the first beam pattern Lp1 and the second beam pattern Lp2 are preferably in contact with each other (Fig. 12 (a)).

FIG. 13 shows the laser light irradiation time per unit area in the granular crystal part and the amorphous part by means of a laser beam pattern as shown in FIG. It is an image figure at the time of satisfying (1A). This example is an example where the laser light irradiation time per unit area in the lateral crystal part and the amorphous part is set to be substantially equal to IL # IA.

Here, the above formula (1A) is satisfied by making the laser light irradiation time per unit area of the granular crystal part slightly longer than the laser light irradiation time per unit area in the amorphous part, but on the contrary, laser light irradiation per unit area on the amorphous part side Even if it is set as the structure which makes time short, the said Formula (1A) can be satisfied. However, if the laser light irradiation time on the amorphous portion side is too short, light absorption energy sufficient for lateral crystallization of the amorphous portion is not obtained, so that the laser light irradiation time per unit area on the granular crystal portion side is slightly longer. This is preferred.

Fig. 14 is similarly adjusted to the laser beam pattern as shown in Fig. 12 (a) by adjusting the laser light irradiation time per unit area in the granular crystal portion and the amorphous portion. It is an image figure at the time of satisfying (1A). This example is an example in which the laser light irradiation time per unit area in the lateral crystal part is also changed to IL < IA. As the laser light to be irradiated, it is preferable to select one having a large wavelength of the difference in the absorptivity between the lateral crystal part and the amorphous part, and to make the irradiation time per unit area in the lateral crystal part and the amorphous part equal to the simpler and preferred configuration. Do.

In the conventional laser annealing, since the beam pattern of the laser light irradiated to the region of the annealed semiconductor film to be annealed at once is generally rectangular, in order to make the laser light irradiation time per unit area of the granular crystal portion longer than the amorphous portion, only the granular crystal portion is irradiated. An annealing process by means of laser light is required separately, ie the number of processes is also increased. As described above, according to the present invention, the laser beam irradiation time per unit area can be changed by the beam pattern, so that the laser light irradiation time per unit area of the granular crystal portion can be lengthened without increasing the number of steps. .

The laser light irradiation conditions to be changed in the granular crystal part and the amorphous part may be the wavelength of the laser light. As shown in FIGS. 2-4, the absorption rate of the irradiated laser light is large in dependence on wavelength, and becomes shorter in shorter wavelength in any crystal region. That is, in the present invention, the granular crystal portion is irradiated with laser light having a single wavelength or a plurality of wavelengths including laser light having a shorter wavelength than the wavelength of the laser beam irradiated to the amorphous portion, and the unit crystal area per unit area in the granular crystal portion and the amorphous portion is irradiated. Laser annealing is performed so that the difference in absorbed light energy is small. In such a configuration, the lateral crystals can be grown more uniformly on the entire surface of the film by reducing the temperature gradient between the granular crystal portions and the amorphous portions as compared with the case where the granular crystal portions and the amorphous portions are treated under the same laser light irradiation conditions.

In this case, in order to make the irradiation light energy per unit area satisfying the above (2A) or (2B), the wavelength of the laser light irradiated to the lateral crystal portion is preferably equal to or greater than the wavelength of the laser light irradiated to the amorphous portion. Do.

The absorption coefficients of the granular crystal part and the amorphous part can be seen from FIG. 3. Since the absorption coefficient is determined according to the wavelength of the laser light irradiated in the amorphous portion, in order to satisfy the above formula (1), the granular crystal portion is such that the absorption coefficient of the laser light of the granular crystal portion is approximately equal to the absorption coefficient of the laser light of the amorphous portion. What is necessary is just to select the wavelength of the laser beam to irradiate. For example, in FIG. 3, when the wavelength of the laser light irradiated to the amorphous portion is around 450 nm, the wavelength of the laser light that is the same as the absorption coefficient of the laser light in the amorphous portion in the granular crystal portion is about 405 nm. Therefore, it is possible to satisfy EP X EA ... (1A) by irradiating the laser light in the vicinity of 450 nm to the amorphous portion and by irradiating the laser light in the vicinity of 405 nm to the granular crystal portion. In addition, when the light source of the wavelength which becomes the same absorption coefficient cannot be selected etc., what is necessary is just to fine-tune the irradiation light intensity of a laser beam, etc.

In order to perform laser annealing by irradiating a laser beam of a single wavelength or a plurality of wavelengths including laser light having a shorter wavelength than that of the laser light irradiated to the amorphous portion with respect to the granular crystal portion, the laser beam L to be irradiated is used as a laser annealing. The semiconductor film can be irradiated simultaneously to a region including at least a portion of the granular crystals generated outside of the lateral crystals and at least a portion of the amorphous crystals remaining uncrystallized, and viewed in the relative scanning direction of the laser light in front and rear ends. A wavelength distribution characteristic in which the side has a beam pattern that is substantially perpendicular to the relative scanning direction and is substantially linear, and includes shorter-wavelength laser light in the beam portion that irradiates the granular crystal portion than the wavelength of the laser light of the beam portion that irradiates the amorphous portion. It is preferable to use a laser beam (see Fig. 15 (a)). By using the laser beam having such a beam characteristic, it is possible to change the wavelength of the laser light irradiated onto the granular crystal part in the laser annealing regardless of the relative scan.

In addition, when performing laser annealing by performing relative scanning, simultaneously irradiating a region including at least a portion of granular crystals generated outside the lateral crystals and at least a portion of the amorphous crystals remaining uncrystallized with respect to the annealed semiconductor film. And a first laser beam Lp1 having a beam pattern in which the front end side and the rear end side are substantially perpendicular to the relative scanning direction and are substantially linear in the direction of the relative scanning direction of the laser light L, and whose wavelength distribution is substantially uniform. And located in front of the first laser beam Lp1 as viewed in the relative scanning direction of the laser light, and can irradiate the granular crystal part, and simultaneously irradiate the second laser beam Lp2 having a shorter wavelength than the first laser beam Lp1. It is preferable to set it as the structure to make. In the above configuration, the first laser beam Lp1 and the second laser beam Lp2 to be irradiated at the same time may be in contact with each other on the film surface of the annealed semiconductor film or may be partially overlapped (FIGS. 15B and 15C). ) Reference).

As shown in the figure, it is preferable that the second laser beam Lp2 can irradiate only the granular crystal portions. However, the second laser beam Lp2 may be irradiated with respect to not only the granular crystal part but also its surroundings within a range where an effect of improving the temperature gradient between the granular crystal part and the amorphous part is obtained.

In the above configuration, the granular crystal part is first annealed only by the second laser beam Lp2 having a shorter wavelength than the first laser beam Lp1, and then the irradiation energy distribution and the beam width are substantially uniform, and the rear end side is the relative scan. Since the whole area irradiated simultaneously by the first laser beam Lp1 which is a straight line substantially perpendicular to the direction is annealed, the end of laser light irradiation can be made substantially the same in any crystal region. When the end time of laser light irradiation differs from region to region, the cooling which starts approximately at the same time as the end of irradiation causes a considerable influence on the annealing of the regions on both sides. In order to obtain a better and more uniform lateral crystal, as described above, it is preferable that the laser light irradiation is terminated at the same time.

In the laser beam of the above configuration, as shown in FIGS. 15B and 15C, the first laser beam Lp1 and the second laser beam Lp2 may be in contact with each other or may be spaced apart from each other. However, since the part spaced apart is cooled not much, the distance between them is shorter, and therefore, it is preferable that the first laser beam Lp1 and the second laser beam Lp2 are in contact with each other.

Fig. 16 is a laser beam pattern as shown in Fig. 15 (a) to irradiate the granular crystal portion with laser light having a shorter wavelength than the wavelength of the laser light irradiated to the amorphous portion, whereby EP ≒ EA. It is an image figure at the time of satisfying (1A). This example is an example in which laser annealing is performed only on the amorphous portion and the granular crystal portion without irradiating the lateral crystal portion with laser light.

17 is similarly irradiated with a laser beam having a wavelength shorter than the wavelength of the laser light irradiated onto the granular crystal part by the laser beam pattern as shown in FIG. It is an image figure at the time of satisfying (1A). This example is an example where laser light is also irradiated to the lateral crystal part, and the wavelength of the laser light irradiated to the lateral crystal part and the amorphous part is made the same to be IL # IA. The wavelength of laser light irradiated in the lateral crystal part and the amorphous part may be changed to IL <IA, but as the laser light to be irradiated, one having a wavelength having a large difference in absorption between the lateral crystal part and the amorphous part is selected and the lateral crystal is selected. It is preferable that the wavelength of the laser light irradiated in the portion and the amorphous portion be the same.

Although the above formula (1A) is satisfied by irradiating the granular crystal part with the laser light having a short wavelength rather than the wavelength of the laser light irradiated to the amorphous part, the wavelength of the laser light on the amorphous part side has a long wavelength. The above formula (1A) can be satisfied. However, as the wavelength of the laser light becomes longer, the difference in absorption in the amorphous portion, the granular crystal portion, and the lateral crystal portion becomes smaller, and between the respective crystal regions sufficient to obtain the effect of the laser annealing method of the present invention using the difference in absorption ratio. Since the difference in the absorptivity is not obtained, a configuration in which the granular crystal portion is irradiated with laser light having a wavelength shorter than the wavelength of the laser light irradiated to the amorphous portion is preferable.

FIG. 18 is irradiated with a laser beam having a wavelength shorter than the wavelength of the laser light irradiated to the granular crystal part by the laser beam pattern as shown in FIG. It is an image figure at the time of satisfying (1A). As in FIG. 16, it is an example when the laser annealing is performed only on the amorphous portion and the granular crystal portion without irradiating the lateral crystal portion with the laser light.

In the conventional laser annealing, since the beam pattern of the laser light irradiated to the region of the annealed semiconductor film to be annealed at once is generally rectangular in shape with a substantially uniform wavelength distribution in the beam, the wavelength of the laser light irradiated to the granular crystal part is shorter than the wavelength of the laser light irradiated to the amorphous part. In order to irradiate laser light of a wavelength, it can irradiate only a granular crystal part, and the annealing process by the laser light of a desired wavelength is needed separately, ie, the number of processes increases. As described above, according to the present invention, by forming the wavelength distribution in the laser beam by the beam pattern, it is possible to change the wavelength of the laser light irradiated to each crystal part, and thus to the granular crystal part without increasing the number of steps, Laser light of a shorter wavelength can be irradiated than the wavelength of the laser light irradiated to the amorphous portion.

As shown in Fig. 1 (a), when only one x-direction relative scan of the laser light L is performed at a predetermined y position, granular crystals are generated on both sides with a region of lateral crystal growth extending in a band shape. do. In the conventional method, granular crystals are formed on both sides with the region of lateral crystal growth extending in a band like the first time even when the second laser beam L is scanned in the x direction with the y position shifted. do.

However, in the method of the present invention, the lateral crystal portion is not remelted even after being irradiated with laser light repeatedly to the lateral crystal portion, and the temperature of the portion is not satisfied with the generation temperature of the granular crystal. As shown in 13, 14, and 16 to 18, when performing x-direction relative scanning of the second laser light L with the y-position shifted, only one side of the region of lateral crystal growth extending in a band shape, Granular crystals are generated only on the amorphous silicon side. That is, in the method of the present invention, the lateral crystallization of the granular crystals produced on one side of the granular crystals formed on both sides with the region of lateral crystal growth extending in the band form at the first time by the second laser annealing is performed. It is possible that the laser annealing is not performed on the side where the laser annealing is first performed. By changing the y position and repeating the same operation seamlessly, approximately lateral crystallization can be achieved.

As described above, in the method of the present invention, a substantially whole surface lateral crystal film is obtained. The "lateral crystal film" is a polycrystalline film composed of band-shaped crystal grains extending in the lateral direction (= relative scanning direction in the case of relative scanning of laser light), and this polycrystalline film is effectively a nearly single crystal film (similar single crystal film). Can be regarded as). The inventors of the present invention have realized a substantially whole-surface lateral crystal film composed of crystal grains having a length in the relative scanning direction of laser light of about 5 µm or more and having a width of 0.2 to 2 µm (SEM / TEM surface photograph of the later example 1 (Fig. 18). ).

The above evaluation is an evaluation when the annealed semiconductor film 20 is a silicon film, but is applicable regardless of the constituent material of the annealed semiconductor film 20.

That is, the laser annealing method of the present invention performs laser annealing by irradiating laser light to a region of a annealed semiconductor film made of an amorphous semiconductor under conditions in which lateral crystals grow, thereby growing lateral crystals,

Further, the laser annealing is again performed on a region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the non-crystallized crystals by shifting the anneal regions to shift the anneal regions. In the laser annealing method performed more than once,

Laser annealing is carried out under the condition that the granular crystalline portion and the amorphous portion of the annealed semiconductor film are fused and the lateral crystalline portion of the annealed semiconductor film is not fused,

Further, the laser annealing is performed by changing the laser light irradiation conditions in the granular crystal portion from the laser light irradiation conditions in the amorphous portion so as to satisfy the following formula (1), preferably the following formula (1A). It is.

EA-EP | <| EA-EPs |. (One),

EP ≒ EA. (1A)

(In formulas (1) and (1A),

EA is the absorbed light energy per unit area of laser light in the amorphous portion,

EPs is the absorbed light energy per unit area of the laser light in the granular crystal part when the laser light is irradiated under the same laser light irradiation conditions as the amorphous part,

EP represents the actual absorbed light energy per unit area of laser light in the granular crystal part, respectively.)

In the laser annealing method of the present invention, it is preferable to perform laser annealing under the conditions satisfying the following formula (2A) or (2B).

IL ≒ IA. (2A),

IL <IA. (2B)

(In formulas (2A) and (2B),

IA is the irradiation light energy per unit area of laser light in the amorphous portion,

IL represents the irradiation light energy per unit area of laser light in the lateral crystal part.)

The material of the annealed semiconductor film is not particularly limited, and examples thereof include silicon, germanium, silicon / germanium, and the like.

According to the laser annealing method of the present invention, the granular crystal portion and the amorphous portion can be selectively melted for high crystallization. Moreover, since the lateral crystal part once produced is made into the condition which does not melt | dissolve, there is no possibility that the lateral crystal part which grew hardly remelts and the crystallinity will change.

Under the condition that the granular crystal portion and the amorphous portion of the annealed semiconductor film are not melted, and the lateral crystal portion of the annealed semiconductor film is not fused, there is a slight difference in the absorption of the laser light in the granular crystal portion and the amorphous portion, and the same laser light irradiation Under the conditions, there is a slight difference in the absorbed light energy per unit area in the granular crystal part and the amorphous part. In this invention, the laser light irradiation conditions in a granular crystal part and an amorphous part are changed, and it is comprised so that the difference of the absorbed light energy per unit area in a granular crystal part and an amorphous part may become small. Therefore, compared with the case where the granular crystal portion and the amorphous portion are treated under the same laser light irradiation conditions, the temperature gradient between the granular crystal portion and the amorphous portion can be made smaller to grow the lateral crystals more uniformly on the entire film surface.

In the laser annealing method of the present invention, by defining the relation of absorbed light energy per unit area in the lateral crystal part, the granular crystal part, and the amorphous part, the granular crystal part and the amorphous part are selectively melted, and once produced The lateral determination part is made on condition that it will not melt | dissolve. Therefore, the laser annealing method of the present invention can be applied to a annealed semiconductor film of any film thickness without any restriction on the wavelength of laser light to be used as long as such conditions can be satisfied.

However, it is preferable to perform laser annealing on condition that the absorption rate of the laser light in a lateral crystal part is smaller than the absorption rate of the laser light in a granular crystal part. 9-11, 13, 14, and 16-18, as shown in the image diagrams, laser annealing was performed under a condition where the difference between the absorption rate in the granular crystal part and the amorphous part and the absorption rate in the lateral crystal part was relatively large. In addition, it is preferable to perform laser annealing so as to finely adjust the difference in absorbed light energy per unit area in the granular crystal part and the amorphous part. In such a configuration, the granular crystal portion and the amorphous portion are not melted, the lateral crystal portion is not melted, and the difference in absorbed light energy per unit area between the granular crystal portion and the amorphous portion is less than that in the same laser light irradiation conditions. It is easy to adjust on the condition to make it small, and it is preferable. When the annealed semiconductor film is an amorphous silicon film, it is preferable to perform laser annealing using 350-600 nm laser light having a large difference between the absorption rate of the laser light in the lateral crystal portion and the absorption rate of the laser light in the granular crystal portion. It is more preferable to perform laser annealing using 350-500 nm laser light.

In the laser annealing method of the present invention, it is preferable to use a continuous oscillation laser light as the laser light. In the pulsed laser light, the time during which the laser light is not irradiated comes periodically while the laser head is turned on. In the case of using a continuous oscillation laser light, the laser light is continuously irradiated onto the film to be annealed while the laser head is turned on, so that a dense and uniform film treatment can be performed, and a larger grain size grows lateral crystals. It is possible to make it preferable. In consideration of the preferable wavelength range used for carrying out the laser annealing of the present invention, it is preferable to use semiconductor laser light as the laser light.

In the laser annealing method of the present invention, as shown in Fig. 1 (b), the laser annealing is performed so that the region to which the laser light is irradiated first and the region to which the laser light is irradiated partially overlap the annealed semiconductor film. It is desirable to.

There is no restriction | limiting in particular about the partial overlapping method of the irradiation area of a laser beam. If the region irradiated with laser light from the back covers 100% of the granular crystal portion formed by the previous laser light irradiation, all of the granular crystal portions are lateral crystallized, and the granular crystal region is between the lateral crystal regions formed by the previous irradiation. The following lateral crystal regions can be formed without.

Depending on the use of the annealed semiconductor film, there may be a case where the granular crystal region may remain between the lateral crystal regions. Even in this case, if the overlap between the region to which the laser light is irradiated from the granular crystal region is 1% or more, the granular crystal region is partially lateral crystallized, so that the lateral crystal region can be widened. As the ratio of the overlap between the region irradiated with the laser light and the granular crystal region from the back becomes larger, the lateral crystal region becomes wider. 50% or more of the ratio of the overlap of the area | region to which a laser beam is irradiated from behind and a granular crystal area | region is preferable.

Depending on the laser annealing conditions, granular crystals are formed at the end in the area where the laser light is directly irradiated, and / or the laser light is not directly irradiated, but in the area where heat is conducted (= immediately outside the area where the laser light is directly irradiated). Is generated.

In the first relative scan in the x-direction, laser light is not directly irradiated, but granular crystals are generated in a region where heat is conducted (= region just outside of the region to which laser light is directly irradiated), and x after changing the y position In the case where laser light is directly irradiated to the granular crystal in the relative scanning in the direction, the granular crystal can be lateral crystallized even if the region to which the laser light is irradiated first and the region to which the laser light is irradiated partially do not overlap each other. However, considering the positional shift between the region where the granular crystal is generated and the irradiation position of the laser light, when the annealing region is shifted with respect to the annealed semiconductor film and the laser annealing is carried out again, the area irradiated with the laser light first and then the laser light are irradiated. It is preferable to perform laser annealing so that the regions to be partially overlap.

Although the case where the laser beam is subjected to relative scanning with respect to the annealed semiconductor film has been described, the method of the present invention is applicable to the case where laser annealing is performed under conditions in which the lateral crystals grow without the relative scan of the laser light.

For example, the laser beam is first irradiated to a predetermined area in a rectangular shape, and the laser beam is first irradiated a plurality of times while decreasing the irradiation width in one direction without changing the irradiation center line for the same area, and then the outside of the area to which the laser light is initially irradiated. From this, the temperature cools, and a temperature gradient occurs between the irradiation center line and the outside, thereby growing lateral crystals extending outward from the irradiation center line. At this time, granular crystals are generated outside the lateral crystal generation region as in the case where the lateral crystals are grown by relative scanning. In this case, the region where the laser light is irradiated plural times and annealed to the same region as the annealed region of one laser anneal. In this method, however, it is necessary to irradiate the laser light a plurality of times by changing the irradiation area with respect to one anneal area using a photomask or the like, so that continuous film treatment is impossible and inefficient, and the entire surface is uniformly processed. It is also difficult.

Therefore, in the laser annealing method of the present invention, it is preferable to perform laser annealing by performing relative scan of the laser light while partially irradiating the laser light to the film to be annealed. In such a configuration, since crystals grow in the relative scanning direction of laser light, lateral crystals can be grown continuously, and the entire surface can be efficiently processed. Moreover, since the whole film surface can be processed continuously and densely, the substantially whole surface lateral crystal film excellent in uniformity is obtained.

By using the laser annealing method of the present invention, a semiconductor film having high crystallinity and uniformity and suitable as an active layer of a thin film transistor (TFT) or the like can be produced at low cost. By using this semiconductor film, semiconductor devices, such as TFT which are excellent in element characteristic (carrier mobility etc.) and element uniformity, can be manufactured.

MEANS TO SOLVE THE PROBLEM This inventor carried out laser annealing on the conditions which satisfy | fill said Formula (1A), when a annealed semiconductor film is an amorphous silicon film, and when it manufactures TFT using the obtained silicon film, carrier movement close | similar to single crystal silicon in the whole surface of a board | substrate is carried out. Also, specifically, the inventors have found that carrier mobility of 500 to 600 cm 2 / Vs is realized.

In the present invention, a substantially crystalline crystal film having almost no granular crystal parts and a seamless crystalline crystal film can be produced. Therefore, the beam end of the laser light and the semiconductor such as the TFT are based on the design information of the formation position of the semiconductor device such as the TFT. It is not necessary to devise a laser beam so as not to overlap the element formation regions of the device, or to selectively irradiate the laser light only to the element formation regions of the semiconductor device such as a TFT, and the device characteristics (carrier mobility, etc.) and element uniformity are eliminated. A semiconductor device such as TFT having excellent properties can be stably manufactured at low cost. An electro-optical device including such a semiconductor device as TFT is excellent in performance such as display quality.

"First Embodiment of Laser Annealing Device"

The structure of the laser annealing apparatus of 1st Embodiment which concerns on this invention with reference to drawings is demonstrated. 19 is an overall configuration diagram of the laser annealing device, and FIG. 20 is a diagram illustrating an internal configuration of one harmonic semiconductor laser light source 121.

The laser annealing device 100 of the present embodiment includes a substrate stage 110 on which a annealed semiconductor film 20, such as an amorphous silicon film, is loaded, a laser head 120 that emits laser light L, and a laser head. The scanning optical system 140 which scans the emission laser light L from 120 is provided.

In the present embodiment, the laser light L emitted from the laser head 120 is scanned by the scanning optical system 140 in the x direction (main relative scanning direction) shown in the figure. In addition, the substrate stage 110 is movable in the y direction shown in the drawing by the stage moving means (not shown), whereby the laser light L is moved in the y direction (negative relative scanning direction) shown in the drawing. Relative scanning is intended. In this embodiment, the relative scanning means which carries out the relative scan of the laser beam L with respect to the annealed semiconductor film 20 by the board | substrate stage 110 and the scanning optical system 140 is comprised.

The laser head 120 has a schematic configuration by a plurality of haptic semiconductor laser light sources 121 disposed without gaps on the water-cooled heat sink 131.

As shown in FIG. 20, each of the multiple-wavelength semiconductor laser light sources 121 includes one multi-lateral semiconductor laser LD (broad area semiconductor laser, not shown) as continuous laser output as a laser light oscillation source. The same number of collimators as the LD package 123 for converting the four LD packages 123 (123A to 123D) and laser beams L1 to L4 emitted from the four LD packages 123 into parallel beams, respectively. The LD unit 122 provided with the lens 124 (124A-124D) is provided.

In the harmonic semiconductor laser light source 121, four LD packages 123 (123A to 123D) are arranged in the x direction (depth direction shown in the drawing of FIG. 19) shown in the drawing.

The harmonic semiconductor laser light source 121 further includes an LD package 123 that reflects the laser light L1 to L4 and the same number of reflection mirrors 125 (125A to 125D),

A polarizing beam splitter 126A into which the laser lights L1 and L2 reflected by the reflection mirrors 125A and 125B are incident;

A polarizing beam splitter 126B is provided to which the laser lights L3 and L4 reflected by the reflecting mirrors 125C and 125D are incident.

The polarizing beam splitters (hereinafter referred to as PBS) 126A and 126B are both cube-shaped PBSs in which two rectangular prisms are bonded to each other, and the light incident surface of the PBS 126B is polarized by the laser lights L3 and L4. The 1/2 wavelength retardation element 127 which shifts a direction by 90 degrees is attached.

When the PBS 126A reflects, for example, a P wave component, the laser light L1 and L2 incident on the PBS 126A are transmitted through the PBS 126A to detect the light output, respectively, and thus the photodiode 129A. 129B), and the P wave component is reflected in the PBS 126A to enter the PBS 126B. Since the ratio of the P wave component and the S wave component can be changed by adjusting the polarization directions of the laser lights L1 and L2, in this case, more light can be effectively used by adjusting in the direction in which the P wave component increases. .

The P waves reflected by the PBS 126A are transmitted as it is by making the PBS 126B reflect (or transmit) the components opposite to the PBS 126A, i.e., reflecting the S waves in this case. You can. On the other hand, the laser light L3, L4 is shifted by 90 ° of the polarization direction by the 1/2 wavelength retardation element 127, respectively, and then enters the PBS 126B. Therefore, in the PBS 126B reflecting the S wave, a P wave component having a small amount of light for light output detection passes through the PBS 126B and enters the photodiodes 129C and 129D. The wave is reflected.

Therefore, in the harmonic semiconductor laser light source 121, the laser light L1 and the laser light L3 having different polarization components and the laser light L2 and the laser light L4 are fast in the PBS 126B. The laser light L1 and L3 polarized and combined in the axial direction and the laser light L2 and L4 polarized and combined are angularly combined in the slow (slow) axial direction.

Since the semiconductor laser LD has a relatively small light output and alone does not obtain the optical power density necessary for high-speed scanning annealing, the laser head 120 includes a haptic semiconductor laser light source having a plurality of LD packages 123. 121 is provided with a plurality. In each of the multiple-wavelength semiconductor laser light sources 121, when the light emitted from the plurality of LD packages 123 is combined only by angular combining, the depth of focus becomes shallow, and there is a concern that the variation in light intensity due to the shift in focus may increase. In the semiconductor laser LD of the multi-lateral mode, the radiation angle in the paste axial direction is 40 to 60 °, and the radiation angle in the slow axial direction is 15 to 25 °. In this embodiment, the laser beams L1 to L4 emitted from the plurality of LD packages 123 are polarized and combined in the fast axial direction, and the angle is combined in the slow axial direction to suppress the variation in light intensity due to the focus shift. , The required optical power density is obtained.

The light exit port of the harmonic semiconductor laser light source 121 propagates in a substantially symmetrical direction with respect to the optical axis, which is included in the individual higher-order lateral mode light emitted from the semiconductor laser LD in the multi-lateral mode. In order to reduce the coherence of two wavefront components, a 1/2 wavelength retardation element 128 is provided which shifts the polarization direction of one of the wavefront components by 90 °. This will be described with reference to FIG. 21.

In the semiconductor laser LD of the multi-lateral mode, a plurality of higher-order lateral modes having different orders are oscillated simultaneously. As shown in Fig. 21 (a), the near-field image (NFP (m)) of any one order m high-order transverse mode light has an intensity distribution having a plurality of peaks according to the order, and between adjacent peaks. The phase is reversed. As schematically shown in FIG. 21B, the optical waveguide R of the semiconductor laser LD has two end faces E1 and E2 parallel to the optical axis A. As shown in FIG. Since the predetermined one order high order lateral mode light is repeatedly emitted from these two end surfaces E1 and E2, the predetermined one order high order lateral mode light is roughly symmetrical with respect to the optical axis A. Two wave front components W1 and W2 which propagate are overlapped.

The two wavefront components W1 and W2 are outlined, the wavefront component W2 is reflected at the end surface E2 when the wavefront component W1 is reflected at the end surface E1, and the wavefront component W1 is the end surface E2. ), The wavefront component W2 is in a reflection relationship at the end surface E1. It is considered that the near field image NFP (m) having the above-described intensity distribution and phase distribution is formed by the interference between these two wavefront components W1 and W2.

In practice, since a plurality of higher order lateral modes having different orders are oscillated simultaneously, the actual near-field image NFP overlaps the near-field images NFP (m) of a plurality of higher order lateral modes having different orders.

Focusing on any one order m higher order transverse mode light, the two wavefront components W1 and W2 propagate in a direction substantially symmetrical with respect to the optical axis A, and are biaxially symmetrical with respect to the optical axis A. It forms a primitive field image (FFP (m)) having intensity distributions P1 and P2.

Higher order transverse mode light is constructed by stacking a plurality of the wavefront components W1 and W2 propagated in a substantially symmetrical direction with respect to the optical axis A even if the orders are different. However, the peak separation angle θ of the bimodal light intensity distributions P1 and P2 is determined by the stripe width and refractive index distribution of the optical waveguide R of the semiconductor laser, the oscillation wavelength, and the degree of higher-order lateral mode. The higher the value is, the larger the peak separation angle θ tends to be.

In the figure, the raw field image (FFP (m)) of the higher-order lateral mode light having the largest peak separation angle θ of the bimodal light intensity distribution P1 and P2 is represented by a solid line, and the circle of other orders of higher-order lateral mode light is shown. The visual field image FFP (m) is shown with the broken line.

Although the coherence between different orders of higher order lateral mode light is small, the coherence of the two wavefront components W1 and W2 constituting individual orders of higher order lateral mode light is high. Therefore, in this embodiment, the half wave phase difference element 128 which provides a 90 degree polarization direction of one wavefront component W2 among two wavefront components W1 and W2 is provided, and these two wavefront components W1 are provided. And the interference with W2) are reduced, and the intensity distribution of the emitted light from the harmonic semiconductor laser light source 121 is configured to be uniform.

In the haptic semiconductor laser light source 121, it is emitted from four LD packages 123 by the collimator lens 124, the reflection mirror 125, the beam splitters 126A and 126B, and the half wavelength retardation elements 127 and 128. A combining optical system for combining light L1 to L4 is configured.

As shown in FIG. 19, on the light emission surface side of the laser head 120 provided with the several harmonic semiconductor laser light source 121, the position and prism angle set in accordance with the formation position of the multiple harmonic semiconductor laser light source 121 The prism array (deflection element 132) which consists of the prism 132a of is attached.

The scanning optical system 140 is composed of an optical scanning mirror (dynamic deflection element) 141 such as a galvano mirror and a parallel light beam lens 142.

The laser light L emitted from the plurality of haptic semiconductor laser light sources 121 mounted on the laser head 120 is deflected by the prism array 132 and is incident on the optical scanning mirror 141 to be in the x direction as shown in the figure. Is injected.

The lens 142 is configured to be scanned in accordance with the optical scanning by the optical scanning mirror 141, and the laser light L deflected by the optical scanning mirror 141 is incident on the lens 142 to form a parallel luminous flux.

In the present embodiment, the spatial light modulator 133 is sandwiched between the units of the plurality of haptic semiconductor laser light sources 121 and the prism array 132.

In the present embodiment, the laser light L having a uniform light intensity distribution is emitted from the units of the plurality of haptic semiconductor laser light sources 121. The spatial light modulator 133 has a distribution in its own light transmission characteristics, and changes the light irradiation intensity distribution of the laser light L to change the laser light irradiation intensity distribution on the film surface of the annealed semiconductor film 20. A desired distribution (for example, the laser light irradiation intensity distribution shown in Figs. 9 to 11), and the laser light irradiation intensity per unit area in the granular crystal part is different from the laser light irradiation intensity per unit area in the amorphous part. Element.

The spatial light modulator 133 is a spatial light modulator having a complex amplitude distribution of an inverse Fourier transform profile that has a desired laser light irradiation intensity distribution on the film surface of the annealed semiconductor film 20. Examples of the spatial light modulator 133 include an optical filter, a diffraction grating, and the like.

There is no restriction | limiting in particular in the installation position of the spatial light modulator 133, As mentioned above, you may install in the laser head 120 itself, or even if it installs in the optical path between the laser head 120 and the annealed semiconductor film 20. do. However, when the spatial light modulator 133 is provided independently of the laser head 120, the spatial light modulator 133 needs to be scanned relative to the relative scan of the laser head 120.

In this embodiment, an elongate laser beam having the y direction shown in the drawing in the longitudinal direction is formed by the above configuration, and the laser beam is irradiated to the annealed semiconductor film 20. This inventor realized the laser beam of 20 micrometers x 4 micrometers-40 micrometers x 8 micrometers whose irradiation light power density in the film surface of the annealed semiconductor film 20 is 0.5-2.7 W / cm <2>, for example.

In the laser annealing apparatus 100 of the present embodiment, the irradiation condition of the laser light L is that the granular crystal portion and the amorphous portion of the annealed semiconductor film 20 are fused, and the lateral crystals of the annealed semiconductor film 20 are formed. It is set on the condition that a part does not melt.

In the laser annealing apparatus 100 of the present embodiment, the laser light irradiation intensity per unit area in the granular crystal portion and the amorphous portion in the granular crystal portion are further satisfied so as to satisfy the following formula (1), preferably the following formula (1A). The laser light irradiation intensity per unit area is changed. In this embodiment, these conditions are satisfied by the spatial light modulator 133.

| EA-EP | <| EA-EPs | (One),

EP ≒ EA. (1A)

(In formulas (1) and (1A),

EA is the absorbed light energy per unit area of laser light in the amorphous portion,

EPs is the absorbed light energy per unit area of the laser light in the granular crystal part when the laser light is irradiated under the same laser light irradiation conditions as the amorphous part,

EP represents the actual absorbed light energy per unit area of laser light in the granular crystal part, respectively.)

In the laser annealing apparatus 100 of this embodiment, it is preferable to set on the laser light irradiation conditions which satisfy | fill following formula (2A) or (2B). In the present embodiment, the spatial light modulator 133 can adjust to satisfy these conditions.

IL ≒ IA. (2A),

IL <IA. (2B)

(In formulas (2A) and (2B),

IA is the irradiation light energy per unit area of laser light in the amorphous portion,

IL represents the irradiation light energy per unit area of laser light in the lateral crystal part.)

As described in Example 1 later, when the laser annealing is performed with the overlap amount at the time of performing the relative scan in the x-direction of the laser light L by changing the y position, the regions for generating granular crystals and lateral crystals are formed. Since it is determined, the laser light irradiation intensity per unit area in the generation region of the granular crystal or the generation region of the granular crystal and the region to be irradiated with respect to the previously generated lateral crystal is the desired value of the spatial light modulator 133. The light modulation characteristics can be designed.

As described with reference to FIG. 11, the laser light irradiation conditions which are changed in the granular crystal part and the amorphous part so as to satisfy the above formula (1) may be laser light irradiation intensity per unit area and irradiation time per unit area.

In this embodiment, the laser beam irradiation intensity distribution and the laser beam shape can be changed by the spatial light modulator 133. By setting the laser light irradiation intensity distribution and the laser beam shape as shown in FIG. 11, the laser light irradiation intensity per unit area and the irradiation time per unit area in the granular crystal part and the amorphous part can be changed.

In the laser annealing apparatus 100 of this embodiment, when the annealed semiconductor film 20 is an amorphous silicon film, it is preferable that the laser annealing conditions satisfy the following formulas (3) and (4).

0.82? EP / EA? (3),

EL / EA? 0.70... (4)

In the laser annealing apparatus 100 of this embodiment, it is preferable that the absorption rate of the laser light in a lateral crystal part is set to the laser light irradiation conditions smaller than the absorption rate of the laser light in a granular crystal part.

In the case where the annealed semiconductor film 20 is an amorphous silicon film, the semiconductor laser (laser light oscillation source) LD mounted on the laser head 120 is the absorption rate of the laser light in the lateral crystal part and the laser in the granular crystal part. It is preferable that the oscillation wavelength having a relatively large difference in light absorption is a semiconductor laser in a wavelength region of 350 to 600 nm, and more preferably a semiconductor laser in an oscillation wavelength in a wavelength region of 350 to 500 nm.

As a laser having an oscillation wavelength in the wavelength region of 350 to 600 nm or 350 to 500 nm, GaN having an active layer containing one or two or more nitrogen-containing semiconductor compounds such as GaN, AlGaN, InGaN, InAlGaN, InGaNAs, GaNAs, etc. And group II-VI compound semiconductor lasers such as ZnO and ZnSe.

The laser annealing apparatus 100 of the present embodiment first performs laser light (when changing the annealing region) when the relative direction of the laser light L is subjected to relative scanning of the laser light L by changing the y position. It is preferable to perform laser annealing so that the area | region to which L) is irradiated and the area | region to which the laser light L is irradiated next partially overlap.

In the laser annealing apparatus 100 of the present embodiment, when the annealed semiconductor film 20 is an amorphous silicon film, the irradiation conditions and the relative scanning conditions of the laser light L are the absorption power density P of the laser light in the amorphous portion. It is preferable that the relative scanning speed v (m / s) of (MW / cm <2>) and laser beam L is set on the conditions which satisfy | fills following formula (5).

0.44v ^0.34143 ? P? 0.56v ^0.34143 ... (5)

The laser annealing method of the present invention can be implemented by using the laser annealing apparatus 100 of the present embodiment.

"2nd Embodiment of a Laser Annealing Device"

Similarly to the first embodiment, the laser annealing device according to the second embodiment of the present invention will be described with reference to FIGS. 19 and 20.

In the laser annealing apparatus 100 of the present embodiment, the laser annealing apparatus 100 of the first embodiment has changed the laser light irradiation intensity per unit area in the granular crystal portion and the amorphous portion. The laser light irradiation time per unit area is changed. Therefore, the structure is the same as that of the first embodiment except that the function of the spatial modulation element 133 for changing the laser beam pattern and the characteristics is different.

In the laser annealing apparatus 200, the laser light L of an elongated rectangular beam pattern having a uniform light intensity distribution from the units of the plurality of haptic semiconductor laser light sources 121 and having the y direction shown in the drawing as the longitudinal direction is It is emitted. The spatial light modulator 133 has a distribution in its own light transmission characteristics, and forms a beam pattern having a larger total irradiation width in the relative scanning direction of the granular crystal portion than the total irradiation width in the relative scanning direction of the amorphous portion, It is an element which can make laser light irradiation time per unit area in a granular crystal part per scan longer than laser light irradiation time per unit area in an amorphous part.

The spatial light modulator 133 is a spatial light modulator having a complex amplitude distribution of an inverse Fourier transform profile that becomes a desired beam pattern on the film surface of the annealed semiconductor film 20. Examples of the spatial light modulator 133 include a phase modulator.

Also in the laser annealing apparatus 200 of this embodiment, it is preferable to satisfy said formula (2A) and (2B) similarly to 1st Embodiment, and for this purpose, the laser light irradiation time per unit area in a lateral crystal part is It is preferable to set so that it may become equal to or less than the laser beam irradiation time per unit area in an amorphous part. In the present embodiment, as described above, the spatial light modulator 133 can be adjusted to satisfy these conditions.

As described in the later embodiments, when the laser annealing is performed with a constant amount of overlap when the y-direction is changed in the x-direction relative scanning of the laser light L, the granular crystal and the lateral crystal generating region are determined. Therefore, the spatial light is formed so as to form a beam pattern of laser light in which the laser light irradiation time per unit area in the generation region of the granular crystal or the region in which the granular crystal is generated and the region to be irradiated with respect to the previously generated lateral crystal is a desired value. What is necessary is just to design the light modulation characteristic of the modulation element 133.

In the present embodiment, the beam pattern of the laser light can be changed by the spatial light modulator 133. By setting it as a beam pattern as shown in FIG. 12, irradiation time per unit area in a granular crystal part and an amorphous part can be changed.

The laser annealing method of the present invention can be performed by using the laser annealing apparatus 200 of the present embodiment.

"Third Embodiment of Laser Annealing Device"

The structure of the laser annealing apparatus of 3rd Embodiment which concerns on this invention with reference to drawings is demonstrated. FIG. 19 is a diagram showing the overall configuration of the laser annealing device (same as in the first embodiment), and FIG. 22 is a diagram showing the internal configuration of one harmonic semiconductor laser light source 121 and 121A.

In the laser annealing apparatus 300 of the present embodiment, the laser annealing apparatus 100 of the first embodiment has changed the laser light irradiation intensity per unit area in the granular crystal portion and the amorphous portion. The wavelength of laser light to be irradiated is changed. Specifically, the granular crystal portion is set to irradiate laser light having a single wavelength or a plurality of wavelengths including the laser light having a shorter wavelength than the wavelength of the laser light irradiated to the amorphous portion.

The laser annealing device 300 of the present embodiment includes a substrate stage 110 on which a annealed semiconductor film 20, such as an amorphous silicon film, is loaded, a laser head 120 that emits laser light L, and a laser. The scanning optical system 140 which scans the emission laser light L from the head 120 is provided.

In the present embodiment, the laser light L emitted from the laser head 120 is scanned by the scanning optical system 140 in the x direction (main relative scanning direction) shown in the drawing. In addition, the substrate stage 110 is movable in the y direction shown in the drawing by the stage moving means (not shown), whereby the laser light L is moved in the y direction (negative relative scanning direction) shown in the drawing. Relative scanning is intended. In this embodiment, the relative scanning means which carries out the relative scan of the laser beam L with respect to the annealed semiconductor film 20 by the board | substrate stage 110 and the scanning optical system 140 is comprised.

The laser head 120 has a schematic configuration by one or more haptic semiconductor laser light sources 121 or haptic semiconductor laser light sources 121A disposed on the water-cooled heat sink 131 without a gap (FIG. 19 is An example configured by a plurality of haptic semiconductor laser light sources 121). The harmonic semiconductor laser light source 121 is a light source that emits a beam having a substantially uniform wavelength distribution, and is the same as that of the first and second embodiments except that the laser light exit port does not include the spatial modulation element 133. I make it a constitution. The combined wave semiconductor laser light source 121A includes the wavelength distribution forming unit 152 in the combined wave semiconductor laser light source 121, and emits the laser light L emitted from the combined wave semiconductor laser light source 121 at a desired position in the beam. It is a light source which emits as laser light L which has the wavelength distribution which changed the wavelength. The configuration of the harmonic semiconductor laser light source 121A is described below (see Fig. 22).

In FIG. 22, the laser light L (L1 to L4) emitted from the harmonic semiconductor laser light source 121 is incident on the dichroic mirror 150 in the wavelength distribution forming unit 152, while the dichroic mirror is provided. The laser light L5 which is emitted from the LD package 123E from the direction orthogonal to the laser light L, and differs in wavelength from the laser light L is incident on 150. In the case of applying to the laser annealing method of the present invention, since the laser light L5 is irradiated only to the granular crystal part, the wavelength is shorter than the wavelength of the laser light L. By using the dichroic mirror 150 having a characteristic of reflecting light of the wavelength of the laser light L5, the laser light L and the laser light L5 can be simultaneously emitted, and the wavelength distribution forming unit 152 ), The irradiation position on the annealed semiconductor film of the laser light L5 is changed by moving the collimator lens 124E by the beam position adjustment 151, and the light condensing characteristic of the collimator lens 124E is changed. The beam width of the laser light L5 can be made desired size. The laser light L and the laser light L5 may overlap or may be independent, and may be designed according to the required beam width and laser light intensity.

In FIG. 22, only one LD package 123E irradiated from the direction orthogonal to the laser light L is arranged, but the number thereof depends on the power required for the laser light irradiated only to a portion having a different wavelength. Is changed. When applied to the laser annealing method of this invention as shown to FIGS. 16-18, a short wavelength laser beam is irradiated to the granular crystal part rather than the wavelength of the laser beam irradiated to an amorphous part, and the difference of the absorption energy of a laser beam is small. Since only one LD package 123E may be sufficient as this is used, even if it is a structure provided with two or more as needed, it does not interfere. The semiconductor laser of the LD package 123E may be single mode or multi mode.

The laser annealing device 300 of the present embodiment has a configuration in which the laser head 120 can form a beam pattern for irradiating laser light having different wavelengths at a desired position on the film to be annealed. It is preferable that the laser head 120 has a granular crystal part as an irradiation target, and is provided with the laser light oscillation source which oscillates the said laser light of short wavelength rather than the wavelength of the laser beam irradiated to an amorphous part. It is preferable that this laser beam source emits only the granular crystal part as an irradiation target. However, as long as it exists in the range from which the improvement effect of the temperature gradient between a granular crystal part and an amorphous part is acquired, not only a granular crystal part but the periphery may be included as an irradiation object.

As described above, the laser head 120 is schematically constituted by one or a plurality of haptic semiconductor laser light sources 121 or haptic semiconductor laser light sources 121A disposed on the water cooling heat sink 131 without a gap. . Since the waveguide semiconductor laser light source 121A can have a different wavelength at a desired position in the beam to be irradiated as described above, the waveguide semiconductor laser light source 121A can be changed in accordance with the width of the portion of the waveguide semiconductor film 20 to be changed in wavelength. By combining the light source 121 or the haptic semiconductor laser light source 121A to configure the laser head 120, a beam having a desired wavelength distribution can be emitted.

The number of the haptic semiconductor laser light source 121 and the haptic semiconductor laser light source 121A depends on the irradiation width by one annealing, and when the irradiation width of one annealing is equal to or less than the irradiation width of the combining semiconductor laser light source 121A, You may comprise only dogs. In addition, when the laser head 120 is comprised by the plurality of haptic semiconductor laser light sources 121, the haptic semiconductor laser light source 121A which emits the laser light which has a wavelength distribution in the said beam, and the wavelength distribution in a beam are It is also possible to form a beam pattern having a desired wavelength distribution by combining the substantially uniform harmonic semiconductor laser light source 121, or to arrange the desired wavelength distribution by varying the wavelength by the number unit of the combined semiconductor laser light source 121. It can also be set as the structure which forms the beam pattern which has. When the beam pattern is formed by varying the wavelength in the unit of the number of the haptic semiconductor laser light sources 121, only the haptic semiconductor laser light source 121 irradiating the portion of the annealed semiconductor film 20 to which the wavelength is desired to change the wavelength is used. You can do it differently.

19 shows the laser annealing device 300 in the case of using the laser head 120 provided with the plurality of haptic semiconductor laser light sources 121.

The laser annealing device 300 of the present embodiment having the above-described configuration, a beam pattern as shown in Figs. 15A to 15C, and the like are formed, and the laser light L5 having a different wavelength is irradiated only to the granular crystal part. It is possible to perform laser annealing, and therefore it is preferably applicable to the laser annealing method of the present invention. MEANS TO SOLVE THE PROBLEM For example, 8x1 micrometer-20x3 which make the y direction shown to the drawing which the irradiation light power density in the amorphous part of the annealed semiconductor film 20 the length of 0.5-5. A long, thin rectangular laser beam was realized.

Also in the laser annealing apparatus 300 of the present embodiment, similarly to the first embodiment, the irradiation conditions of the laser light L are such that the granular crystal part and the amorphous part of the annealed semiconductor film 20 are fused and the annealed semiconductor film The lateral crystal part of (20) is set on the conditions which do not melt | dissolve, specifically, the wavelength of the laser beam irradiated in a granular crystal part and an amorphous part is changed. Specifically, the granular crystal portion is set to irradiate laser light having a single wavelength or a plurality of wavelengths including the laser light having a shorter wavelength than the wavelength of the laser light irradiated to the amorphous portion.

As described in the later embodiments, when the laser annealing is performed with a constant amount of overlap when the y-direction is changed in the x-direction relative scanning of the laser light L, the granular crystal and the lateral crystal generating region are determined. Therefore, the laser head 120 forms a beam pattern of the laser light in which the wavelength of the irradiated laser light becomes a desired value in the generation region of the granular crystal or the generation region of the granular crystal and the region to be irradiated with respect to the previously generated lateral crystal. And the harmonic semiconductor laser light sources 121 and 121A. According to the laser annealing apparatus 300 of this embodiment, the beam pattern suitable for the laser annealing method of this invention as shown to FIG. 15 (a)-(c) can be easily formed.

In the present embodiment, the beam pattern of the laser light can be changed by the laser head 120 and the haptic semiconductor laser light sources 121 and 121A. By setting it as the beam pattern shown in FIG. 15, the laser beam of single or multiple wavelengths containing the laser beam of short wavelength rather than the wavelength of the laser beam irradiated to an amorphous part with respect to a granular crystal part can be irradiated.

The light emitted from the LD package 123E irradiating only the granular crystal portion in the harmonic semiconductor laser light source 121A has a relatively large difference between the absorption rate of the laser light in the lateral crystal portion and the absorption ratio of the laser light in the granular crystal portion. It is preferable that it is laser light of the wavelength of 350-600 nm, and it is more preferable that it is laser light of the wavelength of 350-500 nm. In addition, in order to satisfy the above formulas (3) and (4), when the annealed semiconductor film 20 is an amorphous silicon film, all laser light including laser light of a single or plural wavelengths irradiated to the granular crystal part, namely It is preferable that the laser light oscillated from all the semiconductor lasers LD mounted in the laser head 120 is laser light of 350-600 nm wavelength, and it is more preferable that it is laser light of 350-500 nm wavelength. As a laser in the wavelength region of 350 to 600 nm or 350 to 500 nm, a GaN-based semiconductor laser having an active layer containing one or two or more nitrogen-containing semiconductor compounds such as GaN, AlGaN, InGaN, InAlGaN, InGaNAs, GaNAs, etc. And II-VI compound semiconductor lasers such as ZnO-based and ZnSe-based.

The laser annealing device 300 according to the present embodiment first changes the y position with respect to the annealed semiconductor film 20 to perform relative scanning in the x direction of the laser light L (when changing the annealing area). It is preferable to perform laser annealing so that the area | region to which L) is irradiated and the area | region to which the laser light L is irradiated next partially overlap.

The laser annealing method of the present invention can be implemented by using the laser annealing apparatus 300 of the present embodiment.

(Design change example)

The laser annealing apparatus of this embodiment is not limited to the said structure, A design change is possible suitably.

As shown to each (a), (b) of FIG. 23, 24, 25, it shows in FIG. 19, without installing the spatial light modulator 133 and the laser package 123E which makes the granular crystal part irradiate. The semiconductor laser light source 134 equipped with one semiconductor laser LD (laser light oscillation source) which selectively irradiates a laser light only to a granular crystal part is attached to the unit of the several multiplexed semiconductor laser light source 121 similar to the above. It is good also as a structure to make. 23B is a top view of the laser head 120 (not shown in the water-cooled heat sink 131).

The semiconductor laser light source 134 is attached immediately before (one side with respect to the relative scanning direction) the one harmonic semiconductor laser light source 121. In the first embodiment, the light emitted from the semiconductor laser light source 134 and the light emitted from the haptic semiconductor laser light source 121 attached thereto overlap the granular crystal portion. In the second and third embodiments, the light emitted from the semiconductor laser light source 134 and the light emitted from the haptic semiconductor laser light source 121 to which it is attached are irradiated to the granular crystal portion. However, the semiconductor laser light source 134 may irradiate not only the granular crystal part but also the surroundings within the range from which the improvement effect of the temperature gradient between a granular crystal part and an amorphous part is obtained.

23-25, (c) has shown the laser beam shape irradiated to the annealed semiconductor film 20. In FIG. Hatching is attached to a portion where the light emitted from the semiconductor laser light source 134 and the light emitted from the combined wave laser laser light source 121 to which the light is overlapped are overlapped. In each figure, (b) and (c) have shown the scale changing.

Even with the structure shown in FIG. 23, the laser beam irradiation intensity per unit area in a granular crystal part can be raised rather than the laser beam irradiation intensity per unit area in an amorphous part and a lateral crystal part, and the laser on a film surface The light irradiation intensity distribution can be made into the desired laser light irradiation intensity distribution shown in FIG.

Even in the configuration shown in FIG. 24, the beam pattern of the laser light L can be a beam pattern having a larger total irradiation width in the relative scanning direction of the granular crystal portion than the total irradiation width in the relative scanning direction of the amorphous portion. As shown in FIG. 13 and FIG. 14, the laser light irradiation time per unit area in the granular crystal part per scan can be made longer than the laser light irradiation time per unit area in the amorphous part.

Even with the structure shown in FIG. 25, the laser beam of the single or multiple wavelength which forms the beam pattern as shown in FIG. 15 and contains laser beam of wavelength shorter than the wavelength of the laser beam irradiated to an amorphous part with respect to a granular crystal part is shown. 16 can be irradiated, the absorption energy distribution in a granular crystal part and an amorphous part can be made uniform.

9, 13, 16 and the like, the semiconductor laser light source 134 is for slightly changing the laser light irradiation intensity per unit area in the granular crystal portion, the laser light irradiation time, and the wavelength of the laser light. The number of semiconductor lasers LD mounted on the semiconductor laser light source 134 is sufficient. However, if a plurality of semiconductor lasers LD are mounted in the semiconductor laser light source 134 as needed, there is no problem. The semiconductor laser LD mounted on the semiconductor laser light source 134 may be single mode or multi mode.

The semiconductor laser light source 134 may be formed independently of the laser head 120 as long as the laser light can be selectively irradiated only on the granular crystal portion without being provided in the laser head 120 itself. However, when the semiconductor laser light source 134 is provided independently of the laser head 120, the semiconductor laser light source 134 needs to be scanned relative to the relative scan of the laser head 120.

In the above embodiment, although the laser beam L is scanned relative to the annealed semiconductor film 20 by the movement of the substrate stage 110 and the optical scanning by the scanning optical system 140, the annealed semiconductor is used. The relative scanning of the laser light L with respect to the film 20 is performed by the mechanical scanning in the x direction and the y direction shown in the drawing of the laser head 120, and the mechanical scanning in the x direction and y direction shown in the drawing of the substrate stage 110. Or by optical scanning in the x direction and the y direction shown in the drawing of the laser light L.

As shown in the above embodiment, since a high output can be obtained and a long and thin laser beam shape can be obtained, the laser head 120 has a haptic semiconductor laser light source 121 including a plurality of semiconductor lasers LD in a multi-lateral mode. It is preferable to mount more than one. Although the case where the number of LDs mounted in the individual harmonic semiconductor laser light source 121 is four was demonstrated, the number can be designed suitably. The laser head 120 may be provided with only a single sum wave semiconductor laser light source 121. The laser head 120 may be provided with only a single semiconductor laser LD.

In addition, although the light source used for the laser annealing apparatus 300 in 3rd Embodiment was comprised by the semiconductor laser, it is possible to oscillate the laser light of the wavelength range of 350 nm-650 nm, and LD excitation which can be continuous oscillation is possible. You may comprise with a 2nd harmonic solid-state laser. The LD excitation second harmonic solid laser capable of continuous oscillation includes a second harmonic of Nd-doped YVO ₄ , a second harmonic of Nd-doped YAG, a second harmonic solid laser of Nd-doped YLF, and the like.

"Semiconductor Film, Semiconductor Device, Active Matrix Substrate"

EMBODIMENT OF THE INVENTION With reference to drawings, the manufacturing method and structure of the semiconductor film of embodiment which concerns on this invention, the semiconductor device using the same, and the active matrix substrate provided with this are demonstrated. In this embodiment, a top gate type pixel switching thin film transistor (pixel switching TFT) and an active matrix substrate having the same will be described as an example. Fig. 26 is a process diagram (sectional view in the thickness direction of the substrate).

First, as shown to Fig.26 (a), the board | substrate 10 is prepared and the film annealed semiconductor film 20 which consists of an amorphous semiconductor is formed into the whole surface of the board | substrate 10. FIG. The case where the annealed semiconductor film 20 is an amorphous silicon (a-Si) film is shown here.

There is no restriction | limiting in particular as the board | substrate 10, It can endure the heat processing in a glass substrate (a quartz glass substrate, a barium borosilicate glass substrate, an alumino borosilicate glass substrate, etc.), the TFT process of this embodiment, and the post process of a TFT process. The board | substrate etc. which provided heat insulation with glass equivalent or more by forming an insulating film on the surface of the plastic substrate, silicon substrate, and metal substrate (stainless substrate etc.) which have heat resistance which is in addition, and have heat insulation more than glass equivalent are mentioned.

The annealed semiconductor film 20 is not formed directly on the substrate 10, but after forming a base film (not shown) such as silicon oxide or silicon nitride on the substrate 10, the annealed semiconductor film is formed thereon. (20) may be formed into a film. There is no restriction | limiting in particular as a film-forming method of the base film and the annealed semiconductor film 20, The vapor-phase growth methods, such as plasma CVD method, LPCVD method, and sputtering method, are mentioned.

There is no restriction | limiting in particular in the film thickness of an underlayer, For example, about 200 nm is preferable. There is no restriction | limiting in particular in the film thickness of the to-anneal semiconductor film 20, 40-120 nm is preferable. As for the film thickness of the annealed semiconductor film 20, about 50 nm is preferable, for example.

Hydrogen is usually contained in the annealed semiconductor film 20 formed by plasma CVD or the like. If crystallization by laser annealing with a large amount of hydrogen is carried out, there is a concern that a problem such as partial peeling of the film due to hydrogen bumping, in which the surface of the bumping film of hydrogen becomes rough, may occur. Therefore, it is preferable to perform dehydrogenation prior to laser annealing. There is no restriction | limiting in particular as a dehydrogenation method, A thermal annealing process (for example, about 500 degreeC, about 10 minutes) etc. are mentioned.

Next, as shown in FIG. 26 (b), the laser annealing of the present invention is performed on the annealed semiconductor film 20 to crystallize the entire surface of the annealed semiconductor film 20. In this embodiment, substantially whole surface lateral crystallization is possible.

Next, as shown in Fig. 26C, the semiconductor film 21 after laser annealing is patterned by the photolithographic method to remove regions other than the element formation region of the TFT. Reference numeral 22 is attached to the semiconductor film after patterning.

Next, as shown in Fig. 26D, a gate insulating film 24 made of SiO ₂ or the like is formed by the CVD method, the sputtering method, or the like. There is no restriction | limiting in particular in the film thickness of the gate insulating film 24, For example, about 100 nm is preferable.

Next, as shown in FIG. 26E, the electrode material is formed and the gate electrode 25 is formed on the gate insulating film 24 by patterning by a photolithographic method.

Next, as shown in FIG. 26 (f), dopants such as P and B are doped into the semiconductor film 22 using the gate electrode 25 as a mask, and the source region 23a and the drain region, which are active regions, are doped. The active layer 23 having 23b is formed. The case where the dopant is P is shown. In the active layer 23, the region between the source region 23a and the drain region 23b becomes the channel region 23c. As for the dope amount, about 3.0 * 10 <^15> ions / cm <2> is preferable, for example. By this step, the semiconductor film 23 serving as the active layer of the TFT is formed.

Next, as shown in FIG. 26 (g), an interlayer insulating film 26 made of SiO ₂ , SiN, or the like is formed, and further, etching such as dry etching or wet etching is performed to form the semiconductor film on the interlayer insulating film 26. The contact hole 27a through the source region 23a of 23 and the contact hole 27b through the drain region 23b are formed.

In addition, the source electrode 28a and the drain electrode 28b are formed in a predetermined region on the interlayer insulating film 26. The source electrode 28a is electrically connected to the source region 23a of the semiconductor film 23 through the contact hole 27a, and the drain electrode 28b is connected to the drain region of the semiconductor film 23 through the contact hole 27b. 23b).

In the present embodiment, the semiconductor film 21 after laser annealing and before patterning, the semiconductor film 22 after patterning and impurity implantation, and the semiconductor film 23 after impurity implantation are all fabricated using the laser annealing technique of the present invention. It is a semiconductor film.

 By the above process, the pixel switching TFT 30 of this embodiment is manufactured.

Next, as shown in FIG. 26 (h), an interlayer insulating film 31 made of SiO ₂ , SiN, or the like is formed, and etching such as dry etching or wet etching is performed to form the source electrode 28a on the interlayer insulating film 31. The contact hole 32 through) is formed.

Further, the pixel electrode 33 is formed in a predetermined region on the interlayer insulating film 31. The pixel electrode 33 is connected to the source electrode 28a of the TFT 30 through the contact hole 32.

Although only a pair of pixel electrodes 33 and TFTs 30 are shown, in practice, a large number of pixel electrodes 33 are formed in a matrix with respect to one substrate 10, and pixels correspond to each pixel electrode 33. The switching TFT 30 is formed.

Usually, one pixel electrode 33 and one pixel switching TFT 30 are formed for one dot for a liquid crystal device, and one pixel electrode 33 and two for one dot for an EL device. Pixel switching TFTs 30 are formed.

The active matrix substrate 40 of this embodiment is manufactured by the above process.

In the manufacture of the active matrix substrate 40, wiring such as a scanning line or a signal line is formed. In some cases, the gate electrode 25 also serves as a scan line, and a scan line may be formed separately from the gate electrode 25. In some cases, the drain electrode 28b also serves as a signal line, and a signal line may be formed separately from the drain electrode 28b.

In this embodiment, since the laser annealing technique of the present invention is used, the semiconductor films 21 to 23 which have high crystallinity and are suitable as active layers of the TFT can be manufactured. The pixel switching TFT 30 of this embodiment manufactured using these semiconductor films 21 to 23 is excellent in device characteristics (carrier mobility and the like) and device uniformity. The active matrix substrate 40 of the present embodiment having the pixel switching TFT 30 is high in performance for the electro-optical device.

In an electro-optical device such as a liquid crystal device or an EL device, a pixel circuit in which a plurality of pixel electrodes and pixel switching TFTs are formed in a matrix on the same substrate, and a drive circuit configured by using a plurality of driver circuit TFTs for driving the pixel portion There is a case where the drive unit having a. The driving circuit usually has a CMOS structure of an N-type TFT and a P-type TFT.

In the laser annealing technique of the present invention, since the annealed semiconductor film 20 can be approximately whole-side lateral crystallization, the active layer of the pixel switching TFT and the active layer of the driving circuit TFT can be formed simultaneously. In the laser annealing technique of the present invention, a TFT for a driving circuit excellent in device characteristics such as carrier mobility can be manufactured.

`` Electro-optical device ''

With reference to drawings, the structure of the electro-optical device of embodiment which concerns on this invention is demonstrated. The present invention is applicable to an EL device, a liquid crystal device, or the like, and an organic EL device will be described as an example. 27 is an exploded perspective view of an organic EL device.

The organic EL device (electro-optical device) 50 of this embodiment emits red light (R), green light (G), and blue light (B), respectively, by applying current on the active matrix substrate 40 of the embodiment. The light emitting layers 41R, 41G, and 41B are formed in a predetermined pattern, and the common electrode 42 and the sealing film 43 are sequentially stacked thereon.

Instead of using the sealing film 43, you may seal with sealing members, such as a metal can or a glass substrate. In this case, you may contain desiccants, such as a calcium oxide.

The light emitting layers 41R, 41G, and 41B are formed in a pattern corresponding to the pixel electrode 33, and one pixel is composed of three dots that emit red light (R), green light (G), and blue light (B). The common electrode 42 and the sealing film 43 are formed on substantially the entire surface of the active matrix substrate 40.

In the organic EL device 50, one of the pixel electrode 33 and the common electrode 42 functions as an anode and the other as a cathode, and the light emitting layers 41R, 41G, and 41B are injected from holes and cathodes injected from the anode. It emits light by the recombination energy of electrons.

In order to improve the luminous efficiency, a hole injection layer and / or a hole transport layer may be provided between the light emitting layers 41R, 41G, and 41B and the anode. In order to improve luminous efficiency, an electron injection layer and / or an electron transport layer may be provided between the light emitting layers 41R, 41G, and 41B and the cathode.

Since the organic EL device (electro-optical device) 50 of the present embodiment is configured by using the active matrix substrate 40 of the above embodiment, the device characteristics (carrier mobility, etc.) and device uniformity of the TFT 30 are determined. It is excellent in electro-optical characteristics, such as display quality.

Examples and comparative examples according to the present invention will be described.

(Example 1)

On the glass substrate, a base film (200 nm thick) made of silicon oxide and an amorphous silicon film (a-Si, 50 nm thick) were sequentially formed by plasma CVD. Thereafter, heat annealing was performed at about 500 ° C. for about 10 minutes to dehydrogenate the amorphous silicon film.

About this amorphous silicon film, substantially the whole surface laser annealing was performed using the laser annealing apparatus 100 (refer FIG. 19 and FIG. 20) of the said embodiment. As the laser light oscillation source, a GaN semiconductor laser (oscillation wavelength 405 nm) was used. The shape of the laser beam on an amorphous silicon film surface was made into the elongate rectangular shape of 20x3 micrometers.

As shown in the image diagram in FIG. 9, the laser light irradiation intensity per unit area in the granular crystal portion is slightly raised than the laser light irradiation intensity per unit area in the amorphous portion and the lateral crystal portion, and is applied to the granular crystal portion and the amorphous portion. Laser annealing was carried out so that the absorbed light energy per unit area in the substrate was approximately the same (EP X EA).

Specifically, the absorption rate of the amorphous portion: the absorption rate of the granular crystal portion = 100: 90, so that the laser light irradiation intensity per unit area in the granular crystal portion is increased by 10% of the laser light irradiation intensity per unit area in the amorphous portion, Laser annealing was performed.

Other conditions were as follows.

<Other conditions>

Relative scanning speed of laser light 0.01 m / s, absorption power density in an amorphous part 0.1 MW / cm <2>, overlap amount 75%.

The overlapping amount of 75% means that when the relative position of the laser beam is scanned in the x-direction at the y position, and then the y position is changed to perform the relative direction of the laser beam in the x-direction, the y position is shifted by 5 µm so that the laser beam is first irradiated by 20 µm. It means that laser annealing was performed so that the irradiation area may overlap 15 micrometers with respect to the width | variety area | region.

SEM photographs and TEM photographs of the film surface after approximately full-surface laser annealing are shown in Figs. 28 (a) and (b). As shown in the figure, under the conditions of the present embodiment, the granular crystal portion and the amorphous portion are melted, but the generated lateral crystal portion is not remelted even after being irradiated with laser light repeatedly, and the granular crystal portion is almost in the entire surface. And a seamless lateral crystal film was obtained. In addition, the growth direction and size shape of the lateral crystals are aligned on the entire surface of the film, and the angle formed between the main relative scanning direction of the laser light and the lateral crystal growth direction on the approximately entire surface of the film can be aligned to 5 ° or less.

(Example 2)

As shown in the image diagram in Fig. 13, the granular crystal portion and the amorphous portion are made with the laser light irradiation time per unit area in the granular crystal portion slightly longer than the laser light irradiation time per unit area in the amorphous portion and the lateral crystal portion. Laser annealing was performed in the same manner as in Example 1 except that the absorbed light energy per unit area in E was approximately equal (EP X EA).

Specifically, in order to make the laser light irradiation time per unit area in the granular crystal part 10% longer than the laser light irradiation time per unit area in the amorphous part, the beam pattern of the laser is formed by the spatial light modulator. Only laser annealing was performed using the laser beam of the beam pattern in which the beam width of the relative scanning direction is long by 10%. As a result, similarly to Example 1, although the granular crystal part and the amorphous part are melted, the generated lateral crystal part is not remelted even after being irradiated with laser light repeatedly, and there are almost no granular crystal parts in the entire surface. In addition, a seamless lateral crystal film was obtained.

(Example 3)

As shown in the image diagram in FIG. 16, the absorbed light energy per unit area in the granular crystal portion and the amorphous portion irradiated by irradiating the granular crystal portion with the shorter wavelength laser light than the wavelength of the laser light irradiated to the amorphous portion is approximately. Laser annealing was carried out in the same manner as in Example 1 except that it was made identical (EP x EA).

Specifically, when the GaN-based laser light having a wavelength of 450 nm is irradiated to the amorphous portion, the wavelength of the laser light having the same absorption rate in the same granular crystal portion is about 405 nm, so the GaN-based laser light having 405 nm is applied to the granular crystal portion. The laser annealing was performed by adjusting the haptic semiconductor laser light source 121 and the laser head 120 so that the absorbed light energy per unit area was approximately equal. As a result, the granular crystal portion and the amorphous portion are also melted in this embodiment, but the generated lateral crystal portion is not remelted even after being irradiated with laser light repeatedly, and there are almost no granular crystal portions in the entire surface. A seamless lateral crystalline film was obtained.

(Comparative Example 1)

Absorption rate of the amorphous portion: In Comparative Example 1 under the condition that the absorption rate of the granular crystal portion = 100: 90, the laser light irradiation intensity per unit area in the granular crystal portion is 10 of the laser light irradiation intensity per unit area in the amorphous portion. By% reduction, the difference in absorbed light energy per unit area between the granular crystal part and the amorphous part was increased. Except for performing laser annealing under these conditions, substantially the entire surface laser annealing was performed in the same manner as in Example 1.

The SEM photograph and the TEM photograph of the film surface after a substantially whole surface laser annealing are shown to FIG. 29 (a), (b). As shown in the figure, this comparative example was not a condition in which the granular crystal part could be sufficiently melted. Therefore, the granular crystal part did not laterally crystallize even after being irradiated with laser light repeatedly. In addition, the granular crystal is the core, and the lateral crystals try to grow in a non-parallel direction (an angular direction of 5 to 45 ° with respect to the scanning direction of the laser light) with respect to the main relative scanning direction of the laser light, and at the same time in the main relative scanning direction. The lateral crystals were about to grow to align, resulting in curved lateral crystals. The proportion of granular crystals to the film area was 30% or more.

(Evaluation of Vg-Id Characteristics)

A TFT was manufactured using the silicon film obtained by the laser annealing of Example 1, and the Vg-Id characteristics (relation between the gate voltage Vg and the drain current Id) of the obtained TFT were evaluated.

Similarly, TFT was manufactured using the silicon film obtained by the laser annealing of the comparative example 1, and the Vg-Id characteristic was evaluated. In Comparative Example 1, two TFTs (Comparative Example 1-A and Comparative Example 1-B) were evaluated.

The results are shown in FIG. In FIG. 30, both the left and right vertical axes represent the same Id value, but the right vertical axis is normally displayed, and the left vertical axis is logarithmic. As shown in the figure, the TFT obtained in Example 1 had higher carrier mobility and better element current characteristics than the TFT obtained in Comparative Example 1.

The laser annealing device of the present invention can be suitably applied to the manufacture of a thin film transistor (TFT) and an electro-optical device having the same.

Fig.1 (a) is a perspective view which shows the form of a lateral crystal and a granular crystal at the time of performing a x-direction relative scan of a laser beam at a predetermined y position, and Fig.1 (b) is a laser beam which changed y position. It is an image top view of the crystallization at the time of carrying out a directional relative scan.

Fig. 2 is a diagram showing the relationship between the wavelength and the refractive index n in the lateral crystal part, the granular crystal part and the amorphous part of the silicon film.

FIG. 3 is a diagram showing the relationship between the wavelength and the absorption coefficient in the lateral crystal part, the granular crystal part, and the amorphous part of the silicon film.

4 is a graph showing the relationship between the wavelength of laser light, the ratio of absorption of granular crystal silicon to the absorption of amorphous silicon, and the ratio of absorption of lateral crystal silicon to absorption of amorphous silicon.

FIG. 5 is a graph showing the relationship between the wavelength of laser light and the absorptivity ratio of lateral crystalline silicon with respect to the absorptivity of amorphous silicon when the film thickness t (nm) = 50,100,200.

It is a figure which shows the relationship between the energy ratio with respect to the absorbed light energy which the surface arrival temperature of laser light becomes 2200 degreeC, the surface arrival temperature of laser light, and the crystal state to generate | occur | produce.

FIG. 7 is a diagram showing a range of absorption power densities at which the surface attainment temperature in the amorphous portion becomes about 2000 ± 200 ° C. with respect to the relative scanning speed of laser light.

Fig. 8 shows the absorption rate distribution, the laser light irradiation intensity distribution, the laser energy absorption energy distribution, and the temperature distribution when the lateral crystal portion, the granular crystal portion, and the amorphous portion are irradiated with 405 nm laser light under the same irradiation conditions. Is an example of an image drawing.

Fig. 9 is an example of an image diagram of the absorption distribution, the distribution of laser light irradiation intensity, the distribution of absorption energy of laser light, and the temperature distribution when the laser annealing method of the present invention is carried out.

Fig. 10 is an example of the image diagram of the absorption distribution, the distribution of laser light irradiation intensity, the absorption energy of laser light, and the temperature distribution when the laser annealing method of the present invention is carried out.

Fig. 11 is an example of the image diagram of the absorption distribution, the distribution of laser light irradiation intensity, the absorption energy of laser light, and the temperature distribution when the laser annealing method of the present invention is carried out.

12 (a) and 12 (b) are examples of beam patterns of laser light in the laser annealing method of the present invention.

Fig. 13 is an example of the image diagram of the absorption distribution, the distribution of laser light irradiation time, the distribution of absorption energy of laser light, and the temperature distribution when the laser annealing method of the present invention is carried out.

14 is an example of the image figure of the absorption distribution, the distribution of the laser light irradiation time, the distribution of the absorption energy of a laser beam, and the temperature distribution at the time of implementing the laser annealing method of this invention.

15 (a) to 15 (c) are examples of beam patterns of laser light in the laser annealing method of the present invention.

16 is an example of the image figure of the absorption distribution, the distribution of the laser light irradiation time, the distribution of the absorption energy of a laser beam, and the temperature distribution at the time of implementing the laser annealing method of this invention.

17 is an example of the image figure of the absorption distribution, the distribution of the laser light irradiation time, the distribution of the absorption energy of a laser beam, and the temperature distribution at the time of implementing the laser annealing method of this invention.

18 is an example of the image figure of the absorption distribution, the distribution of the laser light irradiation time, the distribution of the absorption energy of laser light, and the temperature distribution at the time of implementing the laser annealing method of this invention.

19 is an overall configuration diagram of a laser annealing device of an embodiment according to the present invention.

20 is a diagram illustrating an internal configuration of one harmonic semiconductor laser light source included in the laser annealing apparatus of FIG. 19.

21 (a) and 21 (b) are diagrams for explaining a structure for reducing coherence of multi-lateral mode light.

It is a figure which shows the internal structure of the one harmonic semiconductor laser light source with which the laser annealing apparatus of FIG. 19 was equipped.

23 (a) to 23 (c) are diagrams showing examples of design changes of the laser annealing apparatus according to the embodiment of the present invention.

(A)-(c) is a figure which shows the example of a design change of the laser annealing apparatus of embodiment which concerns on this invention.

25 (a) to 25 (c) are diagrams showing examples of design changes of the laser annealing apparatus according to the embodiment of the present invention.

26 (a) to 26 (h) are process diagrams showing a semiconductor film of an embodiment according to the present invention, a semiconductor device using the same, and a method for producing an active matrix substrate having the same.

It is a figure which shows the structure of the organic electroluminescent apparatus (electro-optical apparatus) of embodiment which concerns on this invention.

Fig. 28 (a) is a SEM surface photograph after laser annealing of Example 1, and Fig. 28 (b) is a TEM surface photograph.

29 (a) is a SEM surface photograph after laser annealing of Comparative Example 1, and FIG. 29 (b) is a TEM surface photograph.

30 is a diagram showing evaluation results of Vg-Id characteristics of TFTs obtained in Example 1 and Comparative Example 1. FIG.

DESCRIPTION OF THE REFERENCE NUMERALS (S)

20: film annealed semiconductor film 21,22: semiconductor film

23: semiconductor film (active layer) 23a: source region (active region)

23b: drain region (active region) 30: TFT (semiconductor device)

40: active matrix substrate 50: organic EL device (electro-optical device)

100,200,300: laser annealing device 110: substrate stage (relative scanning means)

120: laser head 121: combined wave semiconductor laser light source

123 (123A to 123D): LD package 133: spatial light modulator

134: semiconductor laser light source 140: scanning optical system (relative scanning means)

LD: semiconductor laser (laser light oscillation source) L: laser light

Claims (66)

One region of a annealed semiconductor film made of an amorphous semiconductor is subjected to laser annealing to irradiate laser light under conditions in which lateral crystals grow, thereby growing lateral crystals, Further, the laser annealing is again performed on the region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the non-crystallized crystals by shifting the anneal regions to perform lateral crystallization. In the laser annealing method performed at least once: The laser annealing is carried out under the condition that the granular crystalline portion and the amorphous portion of the annealed semiconductor film are fused and the lateral crystalline portion of the annealed semiconductor film is not fused, Furthermore, the laser annealing method is performed by changing the laser light irradiation conditions in the granular crystal part to the laser light irradiation conditions in the amorphous part so as to satisfy the following formula (1). EA-EP | <| EA-EPs |. (One) (In the formula (1) EA is the absorbed light energy per unit area of laser light in the amorphous portion, EPs is the absorbed light energy per unit area of the laser light in the granular crystal part when the laser light is irradiated under the same laser light irradiation conditions as the amorphous part, EP represents the actual absorbed light energy per unit area of laser light in the granular crystal part, respectively.) The laser annealing according to claim 1, wherein the laser annealing is performed by changing the laser light irradiation conditions in the granular crystal portion to the laser light irradiation conditions in the amorphous portion so as to satisfy the following formula (1A). Way. EP ≒ EA. (1A) (EP and EA in Formula (1A) are the same as above.) The laser annealing method according to claim 1, wherein the laser annealing is performed under conditions satisfying the following formula (2A) or (2B). IL ≒ IA. (2A), IL <IA. (2B) (In formulas (2A) and (2B), IA is the irradiation light energy per unit area of laser light in the amorphous portion, IL represents the irradiation light energy per unit area of laser light in the lateral crystal part.) The semiconductor device of claim 1, wherein the annealed semiconductor film is an amorphous silicon film, A laser annealing method, wherein the laser annealing is performed under conditions satisfying the following formulas (3) and (4). 0.82? EP / EA? (3), EL / EA? 0.70... (4) (EA and EP in Formula (3) and (4) are as above. EL represents the absorbed light energy per unit area of laser light in the lateral crystal part.) The laser annealing method according to claim 1, wherein the laser annealing is performed under a condition that an absorption rate of the laser light in the lateral crystal portion is smaller than an absorption rate of the laser light in the granular crystal portion. The laser annealing method according to claim 1, wherein continuous oscillation laser light is used as the laser light. The laser annealing method according to claim 1, wherein semiconductor laser light is used as the laser light. 8. The film according to claim 7, wherein the annealed semiconductor film is an amorphous silicon film, A laser annealing method using laser light in a wavelength range of 350 to 600 nm as the laser light. The laser annealing according to claim 1, wherein the laser annealing is performed again by shifting an anneal region with respect to the annealed semiconductor film. And the laser annealing is performed such that the region to which the laser light is irradiated first and the region to which the laser light is irradiated partially overlap with respect to the film to be annealed. The laser annealing method according to claim 1, wherein the laser annealing is performed by performing a relative scan of the laser light while partially irradiating the laser light to the annealed semiconductor film. The semiconductor device of claim 10, wherein the annealed semiconductor film is an amorphous silicon film, The laser annealing is performed under the condition that the absorption power density (P) (MW / cm 2) of the laser light and the relative scanning speed (v) (m / s) of the laser light in the amorphous portion satisfy the following formula (5). Laser annealing method, characterized in that. 0.44v ^0.34143 ? P? 0.56v ^0.34143 ... (5) The laser annealing method according to any one of claims 1 to 11, wherein the laser light irradiation conditions to be changed in the granular crystal portion and the amorphous portion are laser light irradiation intensity per unit area. 12. The laser according to any one of claims 1 to 11, wherein the laser light irradiation conditions to be changed in the granular crystal portion and the amorphous portion are laser light irradiation intensity per unit area and irradiation time per unit area. Annealing method. The laser annealing method according to any one of claims 1 to 9, wherein the laser light irradiation conditions to be changed in the granular crystal portion and the amorphous portion are laser light irradiation time per unit area. The laser annealing method according to claim 14, wherein the laser light irradiation time per unit area in the lateral crystal part is equal to or less than the laser light irradiation time per unit area in the amorphous part. 15. The laser annealing method according to claim 14, wherein the laser annealing is performed by performing a relative scan of the laser light while partially irradiating the laser light to the annealed semiconductor film. 17. The film of claim 16, wherein the annealed semiconductor film is an amorphous silicon film, The laser annealing is performed under the condition that the absorption power density (P) (MW / cm 2) of the laser light and the relative scanning speed (v) (m / s) of the laser light in the amorphous portion satisfy the following formula (5). Laser annealing method, characterized in that. 0.44v ^0.34143 ? P? 0.56v ^0.34143 ... (5) The method of claim 16, wherein the beam pattern of the laser light, Irradiation at the same time may be performed simultaneously with respect to a region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the amorphous crystals remaining uncrystallized, and also compared with the total irradiation width in the relative scanning direction of the amorphous portion. A laser annealing method, characterized in that the beam pattern has a broad irradiation width in the relative scanning direction of the granular crystal part. 19. The method of claim 18, wherein as the laser light, It is possible to irradiate simultaneously the region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the amorphous crystals that remain uncrystallized, and further, the front side and the rear end by looking in the relative scanning direction of the laser light. A first beam pattern having a straight side and a straight line with respect to the relative scanning direction of the laser light; It has a beam pattern of the shape which is located in the front side of the said 1st beam pattern looking at the relative scanning direction of the said laser beam, and matched the 2nd beam pattern which can irradiate the said granular crystal part, And laser light having a uniform irradiation energy distribution of at least the first beam pattern portion. 20. The laser annealing method according to claim 19, wherein the beam pattern of the laser light is a beam pattern having a shape in which the first beam pattern and the second beam pattern are brought into contact with each other. The laser annealing method according to any one of claims 1 to 9, wherein the laser light irradiation conditions to be changed in the granular crystal part and the amorphous part are wavelengths of the laser light. 22. The laser annealing according to claim 21, wherein the granular crystal part is irradiated with laser light having a single wavelength or a plurality of wavelengths including laser light having a shorter wavelength than the wavelength of the laser light irradiated to the amorphous part. Laser annealing method. 22. The laser annealing method as set forth in claim 21, wherein said laser annealing is performed by performing a relative scan of said laser light while partially irradiating said laser light to said annealed semiconductor film. 24. The semiconductor device of claim 23 wherein the annealed semiconductor film is an amorphous silicon film, The laser annealing is performed under the condition that the absorption power density (P) (MW / cm 2) of the laser light and the relative scanning speed (v) (m / s) of the laser light in the amorphous portion satisfy the following formula (5). Laser annealing method, characterized in that. 0.44v ^0.34143 ? P? 0.56v ^0.34143 ... (5) 24. The semiconductor device of claim 23 wherein the annealed semiconductor film is It is possible to simultaneously irradiate a region including at least a portion of the granular crystal generated outside the lateral crystal and at least a portion of the amorphous crystal remaining uncrystallized, and the front side and the rear end side are viewed in the relative scanning direction of the laser light. Has a beam pattern perpendicular to the relative scanning direction and straight; The laser annealing is performed by irradiating a laser beam having a wavelength distribution characteristic including the laser light with a shorter wavelength than the wavelength of the laser light of the beam portion irradiating the amorphous portion to the beam portion irradiating the granular crystal portion. Laser annealing method. 24. The semiconductor device of claim 23 wherein the annealed semiconductor film is It is possible to simultaneously irradiate a region including at least a portion of the granular crystal generated outside the lateral crystal and at least a portion of the amorphous crystal remaining uncrystallized, and the front side and the rear end side are viewed in the relative scanning direction of the laser light. A first laser beam having a beam pattern perpendicular to the relative scanning direction and having a uniform wavelength distribution, The laser annealing is performed in front of the first laser beam by looking in the relative scanning direction of the laser light and irradiating the granular crystal part, and simultaneously irradiating a second laser beam having a shorter wavelength than the first laser beam to perform the laser annealing. Laser annealing method characterized in that. 27. The method according to claim 26, wherein the first laser beam and the second laser beam are in contact with each other on the film surface of the annealed semiconductor film, or under the condition that the first laser beam and the second laser beam partially overlap each other. A laser annealing method characterized by performing laser annealing. A laser head mounted with a single or plural laser light oscillation sources, One region of a annealed semiconductor film made of an amorphous semiconductor is subjected to laser annealing to irradiate laser light under conditions in which lateral crystals grow, thereby growing lateral crystals, Further, the laser annealing is again performed on a region including at least a part of the granular crystals generated outside the lateral crystals and at least a part of the non-crystallized crystals by shifting the annealing regions to shift the annealing regions to perform lateral crystallization. In a laser annealing apparatus that is performed at least once: The granular crystal portion and the amorphous portion of the pyrianneal semiconductor film are melted, and the lateral crystal portion of the pyrianneal semiconductor film is set to a laser light irradiation condition that does not melt, Moreover, the laser annealing apparatus in the said granular crystal part is changed with the laser light irradiation condition in the said amorphous part so that following formula (1) may be satisfied. The laser annealing apparatus characterized by the above-mentioned. EA-EP | <| EA-EPs |. (One) (In the formula (1) EA is the absorbed light energy per unit area of laser light in the amorphous portion, EPs is the absorbed light energy per unit area of the laser light in the granular crystal part when the laser light is irradiated under the same laser light irradiation conditions as the amorphous part, EP represents the actual absorbed light energy per unit area of laser light in the granular crystal part, respectively.) The laser annealing device according to claim 28, wherein the laser light irradiation conditions in the granular crystal portion are changed from the laser light irradiation conditions in the amorphous portion so as to satisfy the following formula (1A). EP ≒ EA. (1A) (EP and EA in Formula (1A) are the same as above.) The laser annealing device according to claim 28, wherein the laser annealing device is set under laser light irradiation conditions that satisfy the following formula (2A) or (2B). IL ≒ IA. (2A), IL <IA. (2B) (In formulas (2A) and (2B), IA is the irradiation light energy per unit area of laser light in the amorphous portion, IL represents the irradiation light energy per unit area of laser light in the lateral crystal part.) 29. The film of claim 28, wherein the annealed semiconductor film is an amorphous silicon film, The laser annealing apparatus is set to the laser light irradiation conditions which satisfy following formula (3) and (4). 0.82? EP / EA? (3), EL / EA? 0.70... (4) (EA and EP in Formula (3) and (4) are as above. EL represents the actual absorbed light energy per unit area of laser light in the lateral crystal part.) 29. The laser annealing apparatus according to claim 28, wherein the absorption rate of the laser light in the lateral crystal portion is set to a laser light irradiation condition smaller than the absorption rate of the laser light in the granular crystal portion. 29. The laser annealing apparatus according to claim 28, wherein said laser light is continuous oscillation laser light. 29. The laser annealing apparatus according to claim 28, wherein said laser light oscillation source is a semiconductor laser. The laser annealing apparatus according to claim 34, wherein the laser light oscillation source is a semiconductor laser having an oscillation wavelength in a wavelength region of 350 to 600 nm. 36. The laser annealing apparatus according to claim 35, wherein the laser light oscillation source is a GaN semiconductor laser or a ZnO semiconductor laser. 29. The laser annealing according to claim 28, wherein the laser annealing is performed again by shifting an anneal region with respect to the annealed semiconductor film. And the laser annealing is carried out so that the region to which the laser light is irradiated first and the region to which the laser light is irradiated partially overlap each other. 29. The laser annealing apparatus according to claim 28, further comprising a relative scanning means for relatively scanning the laser light while partially irradiating the laser light to the annealed semiconductor film. The film of claim 38, wherein the annealed semiconductor film is an amorphous silicon film, The absorption power density (P) (MW / cm 2) of the laser light and the relative scanning speed (v) (m / s) of the laser light in the amorphous portion are set to laser light irradiation conditions that satisfy the following formula (5). Laser annealing device, characterized in that. 0.44v ^0.34143 ? P? 0.56v ^0.34143 ... (5) 40. The laser annealing apparatus according to any one of claims 28 to 39, wherein the laser light irradiation conditions that are changed in the granular crystal portion and the amorphous portion are laser light irradiation intensity per unit area. 41. The granularity according to claim 40, wherein the laser beam irradiation intensity distribution on the film surface of the annealed semiconductor film on the laser head itself or on the optical path between the laser head and the annealed semiconductor film is a desired distribution. A laser annealing device is provided, wherein a spatial light modulator is provided in which the laser light irradiation intensity per unit area in the crystal portion is different from the laser light irradiation intensity per unit area in the amorphous portion. 42. The laser annealing device according to claim 41, wherein the spatial light modulator is a device having a complex amplitude distribution of an inverse Fourier transform profile having a desired distribution as the laser light irradiation intensity distribution on the film surface of the annealed semiconductor film. Device. 41. The laser annealing apparatus according to claim 40, wherein the laser head oscillation source for selectively irradiating laser light only to the granular crystal portion is provided on the laser head itself or independently of the laser head. 40. The laser beam irradiation conditions changed in the granular crystal part and the amorphous part are laser beam irradiation intensity per unit area and irradiation time per unit area. Laser annealing device. 38. The laser annealing apparatus according to any one of claims 28 to 37, wherein the laser light irradiation conditions that are changed in the granular crystal portion and the amorphous portion are laser light irradiation time per unit area. The laser annealing device according to claim 45, wherein the laser light irradiation time per unit area in the lateral crystal portion is set to be equal to or less than the laser light irradiation time per unit area in the amorphous portion. 46. The laser annealing apparatus according to claim 45, further comprising a relative scanning means for relatively scanning said laser light while partially irradiating said laser light to said annealed semiconductor film. 48. The semiconductor device of claim 47 wherein the annealed semiconductor film is an amorphous silicon film, The absorption power density (P) (MW / cm 2) of the laser light and the relative scanning speed (v) (m / s) of the laser light in the amorphous portion are set to laser light irradiation conditions that satisfy the following formula (5). Laser annealing device, characterized in that. 0.44v ^0.34143 ? P? 0.56v ^0.34143 ... (5) 48. The method of claim 47, wherein the laser light, Irradiation at the same time may be performed simultaneously with respect to a region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the amorphous crystals remaining uncrystallized, and also compared with the total irradiation width in the relative scanning direction of the amorphous portion. A laser annealing device, characterized in that it has a beam pattern having a large total irradiation width in the relative scanning direction of the granular crystal part. The method of claim 49, wherein the laser light, It is possible to irradiate simultaneously the region including at least a portion of the granular crystals generated outside the lateral crystals and at least a portion of the amorphous crystals that remain uncrystallized, and further, the front side and the rear end by looking in the relative scanning direction of the laser light. A first beam pattern having a straight side and a straight line with respect to the relative scanning direction of the laser light; It has a beam pattern of the shape which is located in the front side of the said 1st beam pattern looking at the relative scanning direction of the said laser beam, and matched the 2nd beam pattern which can irradiate the said granular crystal part, And at least the irradiation energy distribution of the first beam pattern portion is uniform. 51. The laser annealing apparatus according to claim 50, wherein the beam pattern of the laser light is a beam pattern having a shape in which the first beam pattern and the second beam pattern are brought into contact with each other. The laser annealing device according to claim 49, wherein a spatial light modulator for forming the beam pattern is provided on the laser head itself or on an optical path between the laser head and the annealed semiconductor film. 53. The laser annealing device according to claim 52, wherein the spatial light modulator is a device having a complex amplitude distribution of an inverse Fourier transform profile for forming the beam pattern on the film surface of the annealed semiconductor film. 50. The laser beam oscillation source according to claim 49, wherein a laser beam oscillation source is formed on the laser head itself or on the granular crystal part independently of the laser head to selectively irradiate laser light to form the second beam pattern. Laser annealing device. The laser annealing device according to any one of claims 28 to 37, wherein the laser light irradiation conditions that are changed in the granular crystal portion and the amorphous portion are wavelengths of the laser light. The laser annealing apparatus according to claim 55, wherein the granular crystal portion is irradiated with laser light having a single wavelength or a plurality of wavelengths including laser light having a shorter wavelength than a wavelength of the laser light radiated onto the amorphous portion. 56. The laser annealing apparatus according to claim 55, comprising relative scanning means for relatively scanning said laser light while partially irradiating said laser light to said annealed semiconductor film. 58. The semiconductor device of claim 57 wherein the annealed semiconductor film is an amorphous silicon film, The absorption power density (P) (MW / cm 2) of the laser light and the relative scanning speed (v) (m / s) of the laser light in the amorphous portion are set to laser light irradiation conditions that satisfy the following formula (5). Laser annealing device, characterized in that. 0.44v ^0.34143 ? P? 0.56v ^0.34143 ... (5) 58. The method according to claim 57, wherein the annealed semiconductor film is It is possible to simultaneously irradiate a region including at least a portion of the granular crystal generated outside the lateral crystal and at least a portion of the amorphous crystal remaining uncrystallized, and the front side and the rear end side are viewed in the relative scanning direction of the laser light. Has a beam pattern perpendicular to the relative scanning direction and straight; And a laser beam having a wavelength distribution characteristic that includes the laser light having a shorter wavelength than the wavelength of the laser light of the beam portion for irradiating the amorphous portion to the beam portion for irradiating the granular crystal portion. 58. The method according to claim 57, wherein the annealed semiconductor film is It is possible to simultaneously irradiate a region including at least a portion of the granular crystal generated outside the lateral crystal and at least a portion of the amorphous crystal remaining uncrystallized, and the front side and the rear end side are viewed in the relative scanning direction of the laser light. A first laser beam having a beam pattern perpendicular to the relative scanning direction and having a uniform wavelength distribution, The laser is characterized by being located in the front side of the first laser beam looking in the relative scanning direction of the laser light, irradiating the granular crystal portion, and irradiating a second laser beam of shorter wavelength than the first laser beam simultaneously. Annealing device. 61. The method of claim 60, wherein the irradiation is performed such that the first laser beam and the second laser beam contact each other or partially overlap the first laser beam and the second laser beam on the film surface of the annealed semiconductor film. Laser annealing device, characterized in that. delete delete delete delete delete

Images