JP2007311819A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve characteristics of entire circuits by eliminating adverse effect of irradiation with overlapped laser beams. <P>SOLUTION: Circuits on a substrate are divided into a circuit region in which analog circuits are mainly formed and a circuit region in which analog tinges are thin. Furthermore, the irradiation area with the laser beam is made larger than the circuit region in which analog circuits are mainly formed, and the entire circuit region in which analog circuits are mainly formed is irradiated with the laser beam without moving the laser beam. As a result, in the circuit region in which analog circuits are mainly formed, irradiation with overlapped laser beams does not substantially exist, and device elements having uniform characteristics are formed therein. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a laser light irradiation process (so-called laser annealing method) in a semiconductor device manufacturing process. In particular, the present invention is a semiconductor material partly or wholly composed of an amorphous component, or a substantially intrinsic polycrystalline semiconductor material, and further damaged by ion irradiation, ion implantation, ion doping, etc. The present invention relates to a method for improving the crystallinity of a semiconductor material or recovering the crystallinity by irradiating a semiconductor material with significantly deteriorated crystallinity with laser light.

In recent years, active research has been conducted on lowering the temperature of semiconductor device processes. This is because a semiconductor element needs to be formed on an insulating substrate such as glass. In addition, there is a demand accompanying miniaturization of elements and multilayering of elements.

In semiconductor processes, the crystallinity of an amorphous component or amorphous semiconductor material contained in a semiconductor material is crystallized, or the crystallinity of a semiconductor material that was originally crystalline but has decreased crystallinity due to ion irradiation. However, it may be necessary to improve the crystallinity. Conventionally, thermal annealing has been used for such purposes. When silicon is used as the semiconductor material, 600 ° C. to 1100
By annealing at a temperature of 0.1 ° C. for 0.1 to 48 hours or longer, amorphous crystallization, recovery of crystallinity, improvement of crystallinity and the like have been made.

In such thermal annealing, generally, the higher the temperature, the shorter the processing time may be.
A long time treatment was required at a temperature of about 00 ° C. Therefore, from the viewpoint of lowering the process temperature, it has been necessary to replace the steps conventionally performed by thermal annealing with other means. Laser light irradiation technology is attracting attention as the ultimate low-temperature process. That is, the laser beam can be applied only to the places where high energy comparable to thermal annealing is required, and it is not necessary to expose the entire substrate to a high temperature. Regarding the laser light irradiation, two methods have been proposed.

The first method uses a continuous wave laser such as an argon ion laser, and irradiates a semiconductor material with a spot beam. This is a method of crystallizing a semiconductor material by slowly solidifying it after the semiconductor material has melted due to the difference in energy distribution inside the beam and the movement of the beam.

The second method is a method in which a semiconductor material is crystallized by irradiating a semiconductor material with a high energy laser pulse using a pulsed laser such as an excimer laser, instantaneously melting and solidifying the semiconductor material.

The problem with the first method is that processing takes time. This is because the maximum energy of the continuous wave laser is limited and the size of the beam spot is at most mm units. On the other hand, in the second method, the maximum energy of the laser is very large, and therefore, mass productivity can be further improved by using a large spot of several cm ² or more.

However, when irradiating a pulse laser, even if energy uniformity can be achieved within the beam of a one-shot pulse by improving the optical system, it is difficult to improve variations in element characteristics due to overlapping pulses. It was. In particular, when the element is located just at the end of the laser beam, the characteristics of the element (especially the threshold voltage of the MOS transistor)
Was quite large and varied.

Regarding a semiconductor device, a threshold voltage variation is considerably tolerable in a digital circuit, but in an analog circuit, a threshold voltage variation between adjacent transistors is zero.
. A value of 02V or less was sometimes required.

The present invention has been made for the purpose of solving this problem. In order to eliminate the variation due to the overlap of the laser beams, ideally, the laser beam is irradiated with a large beam that can irradiate the entire circuit in a lump, but this is practically impossible. Therefore, in the present invention, sufficient characteristics can be obtained as a whole by dividing the substrate into a relatively narrow region where the laser beams do not overlap and a relatively wide region where the laser beams overlap.

In the present invention, the circuit on the substrate is divided into a circuit area centering on the analog circuit and a circuit area having a thin analog element, and the size of the laser beam is centered on the analog circuit. It is possible to irradiate the entire circuit area centering on the analog circuit with the laser light without substantially moving the laser light.

In the circuit area centered on the analog circuit, the laser light is irradiated without substantially moving the laser. In other words, in the circuit area centered on the analog circuit, the overlap of the laser beams is substantially absent.

On the other hand, in a circuit area with thin analog elements, laser light is irradiated by scanning the laser light. As a result, laser beam overlap occurs in this region.

For example, in a liquid crystal display (monolithic liquid crystal display) in which an active matrix circuit and a peripheral circuit (driver circuit) for driving the active matrix circuit are formed on the same substrate, the circuit area centering on an analog circuit is active. It is a driver circuit that drives a matrix, and in particular, a source driver (column driver) circuit that outputs an analog signal. On the other hand, the thin circuit area of analog elements is an active matrix circuit or a gate driver (scan driver) circuit.

In order to implement the present invention, it is necessary to adjust the shape of the laser beam to such a circuit, or to adjust the shape of the circuit to the laser beam. Is desirable. In addition, for example, the column driver and the scan driver of the liquid crystal display are formed substantially orthogonally, so to perform these processes, the direction of the laser beam may be changed, and the direction of the substrate is rotated approximately 1/4. (More generally, (n / 2
+1/4) (where n is a natural number) rotation).

By performing the processing as described above, the analog circuit region cannot be overlapped and is governed only by the in-plane uniformity of the laser beam. As a result, an element with uniform characteristics can be formed by sufficiently improving the in-plane uniformity of the laser beam. On the other hand, in the circuit area where analog elements are thin, variation in characteristics due to overlapping of laser beams is unavoidable, but in the first place, in such a circuit, a slight variation is allowed, so this is not substantially a problem. .

In this way, according to the present invention, as a whole circuit formed on the substrate, adverse effects due to the overlap of laser beams can be removed, and the characteristics of the whole circuit can be improved.

In the present invention, the shape of the object to be irradiated with the laser may be a film shape having no pattern, or may be a shape in which the shape of the device is almost completed. The following examples illustrate the invention in more detail.

With the laser beam irradiation technique of the present invention, the characteristics of the semiconductor circuit as a whole could be improved while maintaining mass productivity. The present invention can be used for all laser processing processes used for semiconductor device processes. In particular, when a TFT is taken up as a semiconductor device, in order to improve the uniformity of the threshold voltage of the TFT, a polycrystalline silicon film is used. When used in the laser irradiation process, the effect is great. In addition, in order to increase the field effect mobility of TFT or the uniformity of on-current, it is effective to use the present invention in the step of activating the impurity element of the source / drain in addition to the above steps. Thus, the present invention is considered industrially useful.

FIG. 4 shows a conceptual diagram of the laser annealing apparatus used in this example. The laser light is oscillated by an oscillator 42, amplified by an amplifier 43 via total reflection mirrors 45 and 46, and further introduced into the optical system 44 via total reflection mirrors 47 and 48. The previous laser beam has a rectangular shape of about 30 × 90 mm ² , but this optical system 64 has a length of 100 to 30 mm.
It is processed into an elongated beam having a width of 0 mm and a width of 10-30 mm. The maximum energy of the laser beam that passed through this optical system was 30 J / shot.

The optical path inside the optical system 44 is shown as in FIG. The laser light incident on the optical system 44 includes a cylindrical concave lens A, a cylindrical convex lens B, and a lateral fly-eye lens C.
, Passing through the fly-eye lens D in the vertical direction. By passing through these fly-eye lenses C and D, the laser light changes from the previous Gaussian distribution type to a rectangular distribution. Further, the light passes through the cylindrical convex lenses E and F, is focused by the cylindrical lens H via the mirror G (mirror 59 in FIG. 5), and is irradiated onto the sample.

In this embodiment, the distances X ₁ and X ₂ in FIG. 5 are fixed, and the distance X ₃ between the virtual focus I (this is caused by the difference in the curved surface of the fly-eye lens) and the mirror G, and the distance X ₄ ,
Adjust the X _5, the magnification M, to adjust the focal length F. That is, between these,
M = (X ₃ + X ₄ ) / X ₅ ,
1 / F = 1 / (X ₃ + X ₄ ) + 1 / X ₅ ,
There is a relationship. In this example, the total optical path length X ₆ was about 1.3 m.

By using a beam processed into such a long and narrow beam, the laser processing capability has been dramatically improved. That is, the strip-shaped beam exits the optical system 44 and is then totally reflected mirror 49.
After that, the sample 51 is irradiated. However, since the width of the beam is approximately the same as or longer than the width of the sample, the sample only needs to be moved in one direction. Therefore, the sample stage and the driving device 50 have a simple structure and are easy to maintain. In addition, an alignment operation (alignment) when setting the sample is easy. In the present invention, in addition to movement in one direction, it is only necessary to have a function of rotating the sample.

On the other hand, if the beam is nearly square, it is impossible to cover the entire surface of the substrate by itself, and the sample must be moved two-dimensionally in the vertical and horizontal directions. However, in this case, the stage driving device becomes complicated, and alignment is also difficult because it must be performed two-dimensionally. Especially when performing alignment manually.
The loss of time in the process is large and productivity is lowered. These devices need to be fixed on a stable base 41 such as a vibration isolator.

The laser apparatus as described above may be configured independently, or other apparatuses such as a plasma CVD film forming apparatus, an ion implantation apparatus (or ion doping apparatus), a thermal annealing apparatus, and other semiconductor manufacturing apparatuses. A combined multi-chamber may be used.

In this embodiment, a so-called monolithic AMLCD in which an active matrix type liquid crystal display device (AMLCD) is formed on the same substrate as a peripheral circuit for driving an active matrix circuit will be described.

In such an apparatus, as shown in FIG. 1A, an active matrix circuit region 14, a column driver 13 and a scan driver 12 are provided on a substrate 11 at the edge thereof. Actually, at this stage of laser irradiation, as is clear from the above process, there is only a uniform film on the substrate, but for easy understanding, the position where the circuit is formed is shown. . Both the column driver 13 and the scan driver 12 have a shift register. However, since the column driver outputs an analog signal, an amplifier (buffer circuit) for that purpose is included.

Among the elements used in such AMLCD, the outline of the manufacturing process of the thin film transistor was as follows.

[1] Formation of base silicon oxide film and amorphous silicon film on glass substrate and / or application of crystallization accelerator (for example, nickel acetate) on amorphous silicon film [2] Crystallization of amorphous silicon film by solid phase growth (example of solid phase growth conditions: 550 ° C., 8 hours,
In nitrogen atmosphere)
[3] Laser treatment for crystallized silicon film (to improve crystallinity)
[4] Formation of island-like silicon region by etching of silicon film [5] Formation of gate insulating film (silicon oxide) [6] Formation of gate electrode [7] Source / drain by implantation of impurity elements (phosphorus, boron, etc.) [8] Activation of implanted impurities by laser irradiation [9] Formation of interlayer insulator [10] Formation of electrodes on source / drain

In this embodiment and the following Embodiments 2 and 3, the laser beam irradiation of [3] is performed in the above process for the purpose of further improving the crystallinity of the polycrystalline silicon film.

FIG. 1 shows the laser processing step of this embodiment. In this embodiment, the laser beam 15 is
It is large enough to irradiate the entire column driver 13, for example, a width of 10 mm and a length of 300
It is a rectangle of mm. First, as shown in FIG. 1B, the substrate was moved so that the column driver was irradiated with laser light. At this stage, the laser beam is not irradiated onto the substrate. Thereafter, the laser beam was irradiated without substantially moving the laser beam and the substrate. Laser light irradiation was performed in the atmosphere, and the substrate temperature was 200 ° C. As a laser, KrF
An excimer laser (wavelength 248 nm) was used. The laser oscillation frequency was 10 Hz, the laser beam energy density was 300 mJ / cm ^ (2), and the laser beam pulse was 10 shots. When the necessary number of shots of laser beam irradiation were completed, the laser beam irradiation was stopped. (Fig. 1 (B))

Thereafter, the position to be irradiated with the laser beam is shifted downward, and the active matrix region 1
4 and the scan driver 12 were moved to a position where the upper end of the scan driver 12 was applied to the laser beam 15. (Figure 1 (C))

Then, the substrate was moved while irradiating the laser beam. For example, the laser oscillation frequency was 10 Hz, the laser beam energy density was 300 mJ / cm ² , and the laser beam scanning speed was 10 mm / s. As a result, the laser beam 15 is shifted by 1 mm. Since the width of the beam is 10 mm, about 10 shots of laser light are irradiated at one place. (Figure 1 (D))

In this way, the laser was scanned to the lower end of the substrate, and the scan driver 12 and the active matrix region 14 were irradiated with laser light. (Figure 1 (E))

In this embodiment, the column driver 13 did not overlap the laser beams. As a result, the threshold voltage of the thin film transistor in the column driver is very small, typically 0.01 V or less in the adjacent thin film transistor and 0.05 V or less in the column driver. The other characteristics were similar. On the other hand, the laser driver overlapped the scan driver 12 and the active matrix region 14. Therefore, for example, the variation of the threshold voltage of the thin film transistor in the scan driver 12 is adjacent, about 0.1 V, and the same in the plane. The same applies to the active matrix region 14. However, this level of variation has no problem in the operation of each circuit.

FIG. 2 shows the laser processing step of this embodiment. Also in this embodiment, the laser beam 25 is
It is large enough to irradiate the entire column driver 23, for example, a width of 10 mm and a length of 200
It is a rectangle of mm. First, as shown in FIG. 2B, the substrate was moved so that the column driver was irradiated with laser light. At this stage, the laser beam is not irradiated onto the substrate. Thereafter, the laser beam was irradiated without substantially moving the laser beam and the substrate. Laser light irradiation was performed in the atmosphere, and the substrate temperature was 200 ° C. As a laser, KrF
An excimer laser (wavelength 248 nm) was used. The laser oscillation frequency was 10 Hz, the laser beam energy density was 300 mJ / cm ² , and the laser beam pulse was 10 shots. When the necessary number of shots of laser beam irradiation were completed, the laser beam irradiation was stopped. (
(Fig. 2 (B))

Thereafter, the position to be irradiated with the laser beam is shifted downward, and the active matrix region 2
The substrate was moved to a position where the upper end of 4 was applied to the laser beam 25. Unlike Example 1, the scan driver 22 was not irradiated with laser light at this time. (Fig. 2 (C))

Then, the substrate was moved while irradiating the laser beam. For example, the laser oscillation frequency was 10 Hz, the laser beam energy density was 250 mJ / cm ² , and the laser beam scanning speed was 10 mm / s. As a result, the laser beam 25 is shifted by 1 mm. Since the width of the beam is 10 mm, about 10 shots of laser light are irradiated at one place. (Fig. 2 (D))

In this way, the laser was scanned to the lower end of the substrate, and the active matrix region 24 was irradiated with laser light. (Figure 2 (E))

Thereafter, the substrate was rotated 1/4. In FIG. 2F, a dotted square 26 is the position of the first substrate. (Fig. 2 (F))

Then, as shown in FIG. 2G, the substrate was moved so that the scan driver 22 was irradiated with laser light. At this stage, the laser beam is not irradiated onto the substrate. Thereafter, the scan driver 22 was irradiated with laser light without substantially moving the laser beam and the substrate. The laser oscillation frequency was 10 Hz, the laser beam energy density was 300 mJ / cm ² , and the laser beam pulse was 10 shots. When the necessary number of shots of laser beam irradiation were completed, the laser beam irradiation was stopped. (Fig. 2 (G))

In this embodiment, not only the column driver 23 but also the scan driver 22 did not overlap the laser beam. In this embodiment, the driver circuit is 300 mJ / cm.
^For the active matrix circuit, 250 mJ was applied while
/ Cm ² of laser light was irradiated. This is because in an active matrix circuit, a thin film transistor having a small leakage current (leakage current when a reverse bias voltage is applied to the gate, also referred to as off-current) is obtained. On the other hand, in the driver circuit, since the thin film transistor is required to operate at high speed, the energy of the laser beam is increased to obtain high mobility.

FIG. 3 shows the laser treatment process of this embodiment. Unlike the first and second embodiments, the present embodiment relates to a monolithic liquid crystal display having driver circuits on the upper, lower, left and right sides of the substrate, and this embodiment is an activation process of such a display (see “ [8] Corresponding to “Activation of implanted impurities by laser irradiation”).

FIG. 6 shows an outline of the entire process of the substrate to be processed according to this embodiment. First, the substrate (
A silicon oxide film having a thickness of 100 to 500 nm, for example, 200 nm, was formed as a base oxide film 102 on (Corning 7059, 300 mm × 200 mm) 101. As a method for forming this oxide film, a sputtering method in an oxygen atmosphere was used. However, in order to further increase mass productivity, TEOS may be formed by decomposition and deposition by plasma CVD. Further, the silicon oxide film thus formed may be annealed at 400 to 650 ° C.

Thereafter, an amorphous silicon film is formed by plasma CVD or LPCVD.
Deposit ~ 500 nm, preferably 40-100 nm, e.g. 50 nm
Crystallization was allowed to stand in a reducing atmosphere at ˜600 ° C. for 8-24 hours. At that time, a small amount of a metal element that promotes crystallization, such as nickel, may be added to promote crystallization. This step may be performed by laser irradiation. Then, the island film 103 was formed by etching the silicon film crystallized in this manner. Furthermore, on this, plasma C
A silicon oxide film 104 having a thickness of 70 to 150 nm, for example, 120 nm was formed by the VD method.

Thereafter, aluminum having a thickness of 100 nm to 3 μm, for example, 500 nm (1 wt% S
An i or 0.1 to 0.3 wt% Sc (scandium) film was formed by sputtering, and this was etched to form the gate electrode 105 and the gate wiring 106. (Fig. 6 (A))

Then, the gate electrode 105 and the gate electrode 106 were anodized through current in an electrolytic solution to form anodic oxides 107 and 108 having a thickness of 50 to 250 nm, for example, 200 nm. The electrolytic solution used was prepared by diluting L-tartaric acid in ethylene glycol at a concentration of 5% and adjusting the pH to 7.0 ± 0.2 using ammonia. Substrate 101 is immersed in the solution, the + side of the constant current source is connected to the gate wiring on the substrate, and the platinum electrode is connected to the − side, and 20 m
A voltage was applied in a constant current state of A, and oxidation was continued until 150 V was reached. In addition, 15
Oxidation was continued at 0 V in a constant voltage state until 0.1 mA or less. This results in a thickness of 20
A 0 nm aluminum oxide coating was obtained.

Thereafter, by ion doping, impurities (here, phosphorus) are implanted into the island-like silicon film 103 in a self-aligning manner using the gate electrode portion (that is, the gate electrode and the surrounding anodic oxide film) as a mask. ), A low concentration impurity region (LDD) 109 was formed.
The dose is 1 × 10 ^{13 to} 5 × 10 ¹⁴ atoms / cm ² , and the acceleration voltage is 10 to 90 kV.
The dose was 5 × 10 ¹³ atoms / cm ² and the acceleration voltage was 80 kV. (Fig. 6 (B))

A silicon oxide film 110 was deposited by plasma CVD. Here, TEOS and oxygen, or monosilane and nitrous oxide were used as source gases. The optimum thickness of the silicon oxide film 110 varies depending on the height of the gate electrode / wiring. For example, when the height of the gate electrode / wiring is about 600 nm including the anodic oxide film, as in this embodiment,
Two times 200 nm to 1.2 μm is preferable, and is 600 nm here. In this film forming process, both the uniformity of the film thickness in the flat portion and the good step coverage are required. As a result, the thickness of the silicon oxide film on the side surface of the gate electrode / wiring is increased by the amount indicated by the dotted line in FIG. (Fig. 6 (C))

Next, the silicon oxide film 108 was etched by performing anisotropic dry etching by a known RIE method. This etching is finished when the etching reaches the gate insulating film 105. The end point of such etching can be controlled, for example, by making the etching rate of the gate insulating film 105 smaller than that of the silicon oxide film 110. As a result of the above steps, the substantially triangular insulators (sidewalls) 111 and 112 remain on the side surfaces of the gate electrode and wiring.

Thereafter, phosphorus was introduced again by ion doping. The dose in this case is
It is preferably 1 to 3 digits greater than the dose in the process of FIG. In this example, the dose was set to 2 × 10 ¹⁵ atoms / cm ^{2, which} is 40 times the dose of the first phosphorus doping. Acceleration voltage is 80 kV
It was. As a result, regions (source / drain) 114 into which high-concentration phosphorus was introduced were formed, and low-concentration regions (LDD) 113 were left below the sidewalls. (Fig. 6 (D
))

Further, irradiation with KrF excimer laser (wavelength 248 nm, pulse width 20 nsec) was performed to activate the doped impurities. The energy density of the laser is 20
0 to 400 mJ / cm ² , preferably 250 to 300 mJ / cm ² was suitable. (Fig. 6 (E))

Finally, a silicon oxide film having a thickness of 500 n is formed on the entire surface as an interlayer insulator 115 by a CVD method.
m formed. Then, contact holes were formed in the source / drain of the TFT, and second-layer aluminum wiring / electrodes 116 and 117 were formed. The thickness of the aluminum wiring was 400 to 600 nm, which was almost the same as that of the gate electrode / wiring.

Through the above steps, a TFT having an N-channel type LDD was completed. In order to activate the impurity region, hydrogen annealing may be further performed at 200 to 400 ° C. In the second-layer wiring 117, the step at the portion over the gate wiring 106 is moderate due to the presence of the sidewall 112, so that the thickness of the second-layer wiring 117 is almost the same as the gate electrode / wiring. Nevertheless, almost no breakage was observed. (Fig. 6 (F))

The following is the step of activating doping impurities by laser irradiation in FIG. 6E among the above steps.

Next, an outline of the configuration of the substrate to be processed in this embodiment will be described. FIG. 7 shows an outline of a cross section of the substrate processed in this example. The substrate is provided with a peripheral drive circuit area and a pixel circuit area. The peripheral drive circuit is composed of NMOS and PMOS TFTs, and the pixel circuit is composed of PMO.
It is composed of S TFT. Note that a pixel electrode is provided in the TFT of the pixel circuit. (Fig. 7)

FIG. 3 shows a state in which the substrate to be processed in this embodiment is viewed from above. As is apparent from FIG. 6E, in the process described below, an interlayer insulator, a second-layer wiring, and the like are not formed. As shown in FIG. 3A, scan drivers 32 and 33, column drivers 34 and 35, and an active matrix circuit 36 are formed on a substrate 31. Also in this embodiment, the laser beam 37 is large enough to irradiate the entire column drivers 34 and 35, and is, for example, a rectangle having a width of 10 mm and a length of 300 mm.

First, as shown in FIG. 3B, the substrate was moved so that the scan driver 32 was irradiated with laser light. At this stage, the laser beam is not irradiated onto the substrate. Thereafter, the laser beam was irradiated without substantially moving the laser beam and the substrate. Laser light irradiation was performed in the atmosphere, and the substrate temperature was 200 ° C. As the laser, a KrF excimer laser (wavelength 248 nm) was used. The laser oscillation frequency was 10 Hz, the laser beam energy density was 300 mJ / cm ² , and the laser beam pulse was 10 shots. When the necessary number of shots of laser beam irradiation were completed, the laser beam irradiation was stopped. (Fig. 3 (B))

After that, the substrate was moved, the scan driver 33 was set to be irradiated with laser light, and laser irradiation was performed again without moving the substrate and the laser beam. In this case, 10 shots of laser light were irradiated under the same conditions as above. When the necessary number of shots were irradiated with the laser beam, the laser beam irradiation was stopped. (Figure 3 (C))

Thereafter, the substrate was rotated 1/4. In FIG. 3D, a dotted square 38 is the position of the first substrate. (Fig. 3 (D))

Thereafter, as shown in FIG. 3E, the substrate was moved so that the column driver 34 was irradiated with laser light. And substantially without moving the laser beam and the substrate,
Laser light was irradiated. The irradiation conditions at this time are also the same as described above, and the pulse of the laser beam is 10
It was a shot. When the necessary number of shots of laser beam irradiation were completed, the laser beam irradiation was stopped. (Figure 3 (E))

Next, the position to be irradiated with the laser light is shifted downward, and the active matrix region 36 is moved.
The substrate was moved to a position where the upper end of the scan drivers (32, 33) was applied to the laser beam 37. Then, the substrate was moved while irradiating the laser beam. For example, the laser oscillation frequency was 10 Hz, the laser beam energy density was 250 mJ / cm ² , and the laser beam scanning speed was 10 mm / s. As a result, the laser beam 25 is shifted by 1 mm. Since the width of the beam is 10 mm, about 10 shots of laser light are irradiated at one place. (Fig. 3 (F))

In this way, the laser was scanned to the lower end of the active matrix circuit 36, and the active matrix region 36 was irradiated with laser light. Laser irradiation was stopped when irradiation to the lower end of the active matrix was completed.

Then, as shown in FIG. 3G, the substrate was moved so that the column driver 35 was irradiated with laser light. And substantially without moving the laser beam and the substrate,
The column driver 35 was irradiated with laser light. The laser oscillation frequency was 10 Hz, the laser beam energy density was 300 mJ / cm ² , and the laser beam pulse was 10 shots. When the necessary number of shots of laser beam irradiation were completed, the laser beam irradiation was stopped. (Fig. 3 (G))

In this embodiment, the laser beams did not overlap at all with the column drivers 34 and 35. On the other hand, in the scan driver, the laser beam overlap does not occur in the laser light irradiation process shown in FIGS. 3B and 3C, but the overlap occurs during the laser irradiation of the active matrix circuit. However, the scan driver is more practical than the column driver because the variation in characteristics is less restrictive and the energy of laser light irradiation to the active matrix circuit is smaller than the energy of the first laser irradiation. There was no effect.

The laser processing method of an Example is shown. (See Example 1) The laser processing method of an Example is shown. (See Example 2) The laser processing method of an Example is shown. (See Example 3) The conceptual diagram of the laser annealing apparatus used in the Example is shown. The conceptual diagram of the optical system of the laser annealing apparatus used in the Example is shown. An outline of a manufacturing process of the TFT element of the example is shown. (See Example 3) A state of a cross section of the TFT circuit is shown. (See Example 3)

Explanation of symbols

11, 21, 31 Substrate 12, 22, 32, 33 Scan driver 13, 23, 34, 35 Column driver 14, 24, 36 Active matrix circuit region 15, 25, 37 Laser beam spot (linear laser beam)
26, 38 Indicates the position of the substrate before rotation

Claims (11)

A first circuit region having an analog circuit;
A second circuit region having a first digital circuit;
A method for manufacturing a semiconductor device having a second digital circuit and having a third circuit region larger than the first and second circuit regions on the same substrate,
Irradiating the entire first circuit area with the linear or rectangular first laser light without moving the irradiation area;
Irradiating the whole of the second and third circuit regions while moving the irradiation region with a linear or rectangular second laser beam,
The first and second laser lights are emitted from one laser light source,
The method for manufacturing a semiconductor device, wherein an irradiation region of the first laser light is larger than the first circuit region. A first circuit region having an analog circuit;
A second circuit region having a first digital circuit;
A method for manufacturing a semiconductor device having a second digital circuit and having a third circuit region larger than the first and second circuit regions on the same substrate,
Irradiating the entire first circuit area with the linear or rectangular first laser light without moving the irradiation area;
Irradiating the whole of the third circuit region while moving the irradiation region with a linear or rectangular second laser beam,
Irradiate the whole of the second circuit region with the linear or rectangular third laser light without moving the irradiation region,
The first to third laser lights are emitted from one laser light source,
The irradiation area of the first laser beam is larger than the first circuit area,
The method for manufacturing a semiconductor device, wherein an irradiation region of the third laser light is larger than the second circuit region. In claim 2,
A method for manufacturing a semiconductor device, wherein the substrate is rotated (n / 2 + 1/4) (n is a natural number) after the first and third circuit regions are irradiated with laser light. In claim 2 or claim 3,
A method for manufacturing a semiconductor device, wherein the energy density of the first and third laser beams is larger than the energy density of the second laser beam. A first circuit region having an analog circuit;
A second circuit region having a first digital circuit;
A method for manufacturing a semiconductor device having a second digital circuit and having a third circuit region larger than the first and second circuit regions on the same substrate,
Forming a semiconductor film on the substrate;
Irradiating the entire first circuit area with the linear or rectangular first laser light without moving the irradiation area;
Irradiating the whole of the second and third circuit regions while moving the irradiation region with a linear or rectangular second laser beam,
The first and second laser lights are emitted from one laser light source,
The irradiation area of the first laser beam is larger than the first circuit area,
A method for manufacturing a semiconductor device, wherein a thin film transistor is formed in each of the first to third circuit regions using the semiconductor film irradiated with the laser light. A first circuit region having an analog circuit;
A second circuit region having a first digital circuit;
A method for manufacturing a semiconductor device having a second digital circuit and having a third circuit region larger than the first and second circuit regions on the same substrate,
Forming an island-shaped semiconductor film in each of the first to third circuit regions on the substrate;
Forming gate electrodes on the island-like semiconductor films through gate insulating films,
Impurities are added to the island-shaped semiconductor film using the gate electrode as a mask,
Irradiating the entire first circuit area with the linear or rectangular first laser light without moving the irradiation area;
Irradiating the whole of the second and third circuit regions while moving the irradiation region with a linear or rectangular second laser beam,
The first and second laser lights are emitted from one laser light source,
The irradiation area of the first laser beam is larger than the first circuit area,
A method for manufacturing a semiconductor device, wherein a thin film transistor is formed in each of the first to third circuit regions using the island-shaped semiconductor film irradiated with the laser light. A first circuit region having an analog circuit;
A second circuit region having a first digital circuit;
A method for manufacturing a semiconductor device having a second digital circuit and having a third circuit region larger than the first and second circuit regions on the same substrate,
Forming a semiconductor film on the substrate;
Irradiating the entire first circuit area with the linear or rectangular first laser light without moving the irradiation area;
Irradiating the whole of the third circuit region while moving the irradiation region with a linear or rectangular second laser beam,
Irradiate the whole of the second circuit region with the linear or rectangular third laser light without moving the irradiation region,
The first to third laser lights are emitted from one laser light source,
The irradiation area of the first laser beam is larger than the first circuit area,
The irradiation area of the third laser beam is larger than the second circuit area,
A method for manufacturing a semiconductor device, wherein a thin film transistor is formed in each of the first to third circuit regions using the semiconductor film irradiated with the laser light. A first circuit region having an analog circuit;
A second circuit region having a first digital circuit;
A method for manufacturing a semiconductor device having a second digital circuit and having a third circuit region larger than the first and second circuit regions on the same substrate,
Forming an island-shaped semiconductor film in each of the first to third circuit regions on the substrate;
Forming gate electrodes on the island-like semiconductor films through gate insulating films,
Impurities are added to the island-shaped semiconductor film using the gate electrode as a mask,
Irradiating the entire first circuit area with the linear or rectangular first laser light without moving the irradiation area;
Irradiating the whole of the third circuit region while moving the irradiation region with a linear or rectangular second laser beam,
Irradiating the whole of the second circuit region with the linear or rectangular third laser light without moving the irradiation region,
The first to third laser lights are emitted from one laser light source,
The irradiation area of the first laser beam is larger than the first circuit area,
The irradiation area of the third laser beam is larger than the second circuit area,
A method for manufacturing a semiconductor device, wherein a thin film transistor is formed in each of the first to third circuit regions using the island-shaped semiconductor film irradiated with the laser light. In claim 7 or claim 8,
A method for manufacturing a semiconductor device, wherein the substrate is rotated (n / 2 + 1/4) (n is a natural number) after the first and third circuit regions are irradiated with laser light. In any one of Claims 7 to 9,
A method for manufacturing a semiconductor device, wherein the energy density of the first and third laser beams is larger than the energy density of the second laser beam. In any one of Claims 1 thru | or 10,
The first circuit region is a source driver region;
The second circuit region is a gate driver region;
The method for manufacturing a semiconductor device, wherein the third circuit region is an active matrix circuit region.

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