TW202038307A - Laser annealing apparatus - Google Patents

Abstract

A laser annealing apparatus that irradiates a region to be modified, in which modification of an amorphous silicon film is to be performed, with a laser beam to perform the modification by growing a crystallized silicon film in the region to be modified, the apparatus comprising a first irradiation unit for radiating a first laser beam that forms a seed crystal region on the amorphous silicon film, and a second irradiation unit that moves a beam spot of the laser beam radiated onto the surface of the amorphous silicon film starting from the seed crystal region so as to cover the region to be modified and performs the modification so that the amorphous silicon film in the region to be modified becomes the crystallized silicon film.

Description

Laser annealing device

The present invention relates to a laser annealing device.

Thin Film Transistor (TFT: Thin Film Transistor) is used to actively drive thin displays (FPD: Flat Panel Display) such as liquid crystal displays (LCD: Liquid Crystal Display), organic EL displays (OLED: Organic Electroluminescence Display), etc. The switching element is used. As a material for the semiconductor layer of a thin film transistor (hereinafter referred to as TFT), amorphous silicon (a-Si: amorphous Silicon) or polycrystalline silicon (p-Si: polycrystalline silicon) is used.

Amorphous silicon has low mobility as an indicator of the mobility of electrons. Therefore, in amorphous silicon, the system cannot fully satisfy the high mobility required in the FPD, which is increasingly high-density and high-definition. Therefore, as the switching element in the FPD, it is desirable to form the channel layer with polysilicon whose mobility is greatly improved compared to amorphous silicon. As a method of forming a polysilicon film, there is an Excimer Laser Annealing (ELA: Excimer Laser Annealing) device using an excimer laser. The amorphous silicon film is irradiated with laser light to recrystallize the amorphous silicon. The method of polysilicon.

It is known that in order to increase the mobility in the direction (source-drain direction) connecting the source and drain in the TFT, the pseudo-single-crystal silicon is crystallized laterally (laterally) along the source-drain direction. Growing technology. In addition, it is known to fabricate TFTs with a polysilicon film as the channel layer in the display part of the FPD, and fabricate TFTs with a high mobility pseudo-single-crystal silicon film as the channel layer in the driving circuit fabricated around the display part. Technology (refer to Patent Document 1). In this patent document 1, it is disclosed that the growth direction corresponds to the source-drain direction of the switching element in the driving circuit, and the growth direction is mixed with the channel layer in the first direction and the channel layer in the second direction. To make the technology of formation. In this prior art, the entire surface of the amorphous silicon film formed on the substrate is subjected to excimer laser annealing to form a polycrystalline silicon film on the entire surface of the substrate. In addition, in this conventional technology, it is equipped with: at necessary locations on the substrate, annealing by continuous wave (CW: Continuous Wave) laser light that moves in the first direction to form growth The process of quasi-single-crystal silicon film in the first direction and annealing by CW laser light moving in the second direction to form a process of quasi-single-crystal silicon film grown in the second direction. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2008-41920 A

[The problem to be solved by the invention]

As mentioned above, in the prior art, as a pre-treatment for forming a pseudo-single-crystal silicon film by lateral crystal growth, it is necessary to perform excimer laser annealing on the entire surface of the amorphous silicon film on the substrate to form polycrystalline silicon. Membrane engineering. In recent years, the size of FPD has been increasing. In the case where excimer laser annealing is performed on the substrate as in the conventional technology, the process of patterning and etching the polysilicon film formed in the area outside the channel layer Department becomes necessary. Therefore, in this conventional technology, there is a problem of increased manufacturing cost. In addition, in this prior art, since the formation of polycrystalline silicon film uses an excimer laser annealing device, when the formation of pseudo-single crystal silicon film, a CW laser annealing device using CW laser as the light source is used. , So there is a problem of increased device cost. Furthermore, in this conventional technology, since multiple projects are required, there is a problem of increasing production tact time.

The present invention was completed in view of the above-mentioned problems, and it is to provide a mine that can selectively form polycrystalline silicon films and pseudo-single-crystal silicon films in necessary areas, reduce manufacturing costs, and shorten production tact time. Laser annealing device and laser annealing method as the purpose. [Means to solve the problem]

In order to solve the above-mentioned problems and achieve the objective, the aspect of the present invention is a laser annealing device, which irradiates laser light on a modified region to be modified for an amorphous silicon film to grow the above-mentioned modified region The crystalline silicon film is modified, and it is characterized by having: a laser light source unit that oscillates the first laser light and the second laser light, and a laser beam irradiation unit that is selected for the surface of the aforementioned amorphous silicon film Irradiating the laser light oscillated from the laser light source unit, the laser annealing device performs: first irradiation, irradiating the amorphous silicon film with the first laser light oscillated from the laser light source unit The laser light is used to form the seed crystal region and the second irradiation is to irradiate the surface of the amorphous silicon film with the second laser light oscillated from the laser light source section using the seed crystal region as a starting point The beam spot of the second laser beam is moved so as to cover the predetermined area for modification, and the amorphous silicon film in the predetermined area for modification is modified so that the amorphous silicon film in the predetermined area for modification becomes the crystalline silicon film. .

As for the above aspect, it is preferable that the predetermined region for modification is the channel layer region of the thin film transistor.

As the above aspect, it is preferable that the first irradiation is set to the amount of energy required to make the amorphous silicon film as a seed crystal for microcrystallization, and the second laser light is a continuous oscillation laser. The irradiation light, the second irradiation mentioned above, is the continuous irradiation of continuous oscillation laser light.

As the above aspect, it is preferable that the laser light source unit includes a light source that oscillates continuous oscillation laser light, and in the first irradiation, the laser light continuously oscillated from the light source is pulsed to pulse the laser light The first laser light oscillates, during the second irradiation, the continuous oscillation laser light oscillated from the light source is directly oscillated.

As the above aspect, it is preferable that the laser light source section includes different light sources, and the first irradiation and the second irradiation use different light sources.

As the above aspect, it is preferable that the predetermined modification area is rectangular, and the first irradiation is along one of the parallel pairs of sides in the predetermined modification area. A row of the aforementioned seed crystal regions is formed, and the aforementioned second irradiation uses the aforementioned seed crystal regions of the aforementioned row as a starting point and faces the other side of the pair of sides facing each other in the predetermined modification area to make the aforementioned The beam spot of the second laser beam moves.

As the above aspect, it is preferable that the predetermined modification area is rectangular, the first irradiation is to form the seed crystal region at a corner of the predetermined modification area, and the second irradiation is Using the seed crystal region formed at the corner as a starting point, the beam spot of the second laser light is made parallel to the side including the one corner from the side including the one corner. Move in a zigzag pattern until the other side of the opposite side.

As the above aspect, it is preferable that the laser beam irradiating part is provided with a spatial light modulator, and the spatial light modulator selectively reflects the laser light oscillated from the laser light source part , And selectively irradiate the laser beam within the predetermined area for modification.

As the above aspect, it is preferable that the aforementioned spatial light modulator is such that a plurality of micro-mirrors are arranged in a matrix, and each of the micro-mirrors can be individually switched to the amorphous silicon film The irradiated state and non-irradiated state of the laser beam on the surface are selectively driven.

As the above aspect, it is preferable that a projection lens is arranged between the spatial light modulator and the amorphous silicon film, and the spatial light modulator is set to be able to be positioned on the optical axis of the projection lens or It rotates around the vertical axis. When the beam spot of the second laser beam is moved, the gap between the micro-mirrors can not be reflected. The direction of the spatial light modulator The projection area of the laser beam of the micro-mirror is displaced in a direction in which the predetermined modification area becomes dense.

As the above aspect, it is preferable that the aforementioned crystalline silicon film is selected from a polycrystalline silicon film and a pseudo-monocrystalline silicon film.

As another aspect of the present invention, there is a laser annealing method in which laser light is irradiated to a modified region to be modified for an amorphous silicon film to grow a crystalline silicon film in the modified region. It is characterized by comprising: a first irradiation process, which is to irradiate the amorphous silicon film with a first laser light to form a seed crystal region, and a second irradiation process, which uses the seed crystal region as a starting point to make the second 2 The beam spot of the laser light is moved to cover the predetermined area of modification and irradiated on the surface of the amorphous silicon film, so that the amorphous silicon film in the predetermined area of modification becomes the aforementioned crystallization Modified by the way of silicon film.

As for the above aspect, it is preferable that the predetermined region for modification is the channel layer region of the thin film transistor.

As the above aspect, it is preferable that the amount of irradiation energy in the irradiation of the first laser light in the first irradiation step is set to the condition that the amorphous silicon film is used as a seed crystal for microcrystallization. The irradiation of the aforementioned second laser light in the second irradiation process is continuous irradiation using continuous oscillation laser light.

As the above aspect, it is preferable to pulse the continuous oscillation laser light used in the second irradiation process and irradiate it as the first laser light.

As the above-mentioned aspect, it is preferable to use different light sources in the first irradiation process and the second irradiation process.

As the above aspect, it is preferable that the predetermined modification area is rectangular, and in the first irradiation process, it is along one of a pair of parallel sides in the predetermined modification area. One side of the above-mentioned seed crystal regions is formed in a row, and in the above-mentioned second irradiation process, the above-mentioned seed region of the above-mentioned row is used as a starting point, and faces among the pair of sides facing each other in the predetermined modification region The other side is to move the beam spot of the aforementioned second laser light.

As the above aspect, it is preferable that the predetermined modification region is rectangular, and in the first irradiation process, the seed crystal region is formed at one corner of the predetermined modification region, and the seed crystal region is formed in the first irradiation step. 2 In the irradiation process, the beam spot of the second laser light is set from the side including the one corner to the side including the one corner, starting from the seed crystal region formed in the corner. The sides become parallel to each other and move in a zigzag pattern until the other side of the pair of sides.

As the above-mentioned aspect, it is preferable that the first irradiation process and the second irradiation process are performed by using a spatial light modulator that selectively reflects laser light. The laser beam is selectively irradiated in the predetermined area for modification.

As the above aspect, it is preferable that the aforementioned spatial light modulator is such that a plurality of micro-mirrors are arranged in a matrix, and each of the micro-mirrors can be individually switched to the amorphous silicon film The irradiated state and non-irradiated state of the laser beam on the surface are selectively driven.

As the above aspect, it is preferable that the spatial light modulator is relative to the predetermined area of modification, and when the beam spot of the second laser light is moved, the gap between the micro mirrors is not The method of reflection is arranged in a direction in which the projection area of the laser beam from the micro-mirror becomes dense in the planned modification area.

As the above aspect, it is preferable that the aforementioned crystalline silicon film is selected from a polycrystalline silicon film and a pseudo-monocrystalline silicon film. [Invention Effect]

According to the laser annealing device and the laser annealing method of the present invention, the polycrystalline silicon film and the pseudo-single crystal silicon film can be selectively formed in the necessary area, and the number of manufacturing processes can be reduced to reduce the manufacturing cost, and the production can be shortened Takt time.

Hereinafter, based on the drawings, the details of the laser annealing apparatus of the embodiment of the present invention will be described. However, the drawings are for illustrative purposes only. Please note that the quantity of each component, the size of each component, the ratio of the size, the shape, etc., may be different from the actual product. In addition, among the various drawings, there are also parts with different sizes or ratios, or different shapes.

The laser annealing device of the present invention is provided with: a laser light source unit that oscillates the laser light and a laser beam irradiation unit that selectively irradiates the surface of the amorphous silicon film oscillated from the laser light source unit The first irradiation and the second irradiation can be performed simultaneously. The first irradiation is to irradiate the amorphous silicon film with the first laser light oscillated from the laser light source unit to form a seed crystal region; the second Irradiation is a method in which the second laser light oscillated from the laser light source unit starts from the seed crystal area, so that the beam spot of the second laser light irradiated to the surface of the amorphous silicon film covers the predetermined area for modification It moves, and the modification is performed in such a way that the aforesaid amorphous silicon film in the predetermined modification area becomes a crystalline silicon film.

The laser annealing method of the present invention includes: a first irradiation process, which is to irradiate an amorphous silicon film with a first laser light to form a seed crystal region, and a second irradiation process, which uses the seed crystal region as a starting point to make The beam spot of the second laser beam is moved so as to cover the predetermined area of modification and irradiated on the surface of the amorphous silicon film, so that the amorphous silicon film in the predetermined area of modification becomes a crystalline silicon film. Come to make improvements.

[First Embodiment] Before the description of the structure of the laser annealing device, an example of the substrate to be processed that is annealed by the laser annealing device will be described. As shown in Figure 1, the substrate 1 to be processed includes a glass substrate 2, and a plurality of gate wirings 3, which are arranged so as to be parallel to the surface of the glass substrate 2 and a gate insulating film 4 , Is formed on the glass substrate 2 and the gate wiring 3, and the amorphous silicon film 5 is deposited on the entire gate insulating film 4. This substrate 1 to be processed will eventually become a TFT substrate with built-in thin film transistors (TFT) and the like. As shown in FIGS. 4 to 6, in the present embodiment, the substrate 1 to be processed is processed along the longitudinal direction (conveying direction T) of the gate wiring 3 in the laser annealing process. Transport.

As shown in FIGS. 4 to 6, in the amorphous silicon film 5 formed on the gate wiring 3, a rectangular modification plan that will eventually become the channel layer region of the TFT is set Area 6. A plurality of regions 6 to be modified are set along the gate wiring 3. The width dimension W (refer to FIG. 4) of the modified region 6 is set to be approximately the same as the width dimension of the channel layer of the manufactured TFT.

(Outline structure of laser annealing device) Hereinafter, the schematic configuration of the laser annealing apparatus 10 of the present embodiment will be described using Figs. 1 to 3. As shown in FIG. 1, the laser annealing device 10 includes a base 11, a laser light source unit 12, a laser beam irradiation unit 13, and a control unit 14.

The base 11 is equipped with a substrate transport means not shown. In this laser annealing apparatus 10, the substrate 1 to be processed is placed on the base 11 and transported in the transport direction (scanning direction) T by a substrate transport means not shown. As shown in FIGS. 4 to 6, this transport direction T is the same direction as the extending direction of the gate wiring 3. That is, in the present embodiment, the laser beam irradiation unit 13 is not moved during the annealing process, but the substrate 1 to be processed is moved.

As shown in Fig. 1, the laser light source unit 12 is provided with: a CW laser light source 15 as a light source, which oscillates continuous oscillation laser light (CW laser light), and a pulse generator 16 to make this CW laser light The laser light is pulsed to generate CW laser pulse light as the first laser light, and the light emitting unit 17 emits the continuous oscillation laser light and the CW laser pulse light toward the laser beam irradiation unit 13 side. The laser light source unit 12 is set to be able to emit two types of laser light, that is, it can directly emit CW laser light as the second laser light and can emit light from the CW laser light source 15 After the CW laser light is pulsed, the pulsed CW laser light is emitted as the first laser light. In the laser light source unit 12, the laser beam LB is emitted from the light emitting unit 17 toward the digital micro mirror device 18 described later in the laser beam irradiation unit 13.

As the CW laser light source 15, various lasers such as semiconductor lasers, solid lasers, liquid lasers, and gas lasers can be used.

The laser beam irradiating part 13 is arranged above the base 11 by a support frame etc. not shown. The laser beam irradiating part 13 is provided with: a digital micro-mirror device (DMD: Digital Micro-mirror Device, a registered trademark of Texas Instruments) as a spatial light modulator 18, and a baffle (absorber) 19, and The micro lens array 20, and the projection lens 21.

As shown in Figs. 1 and 2, the digital micro mirror device (hereinafter referred to as DMD) 18 is provided with: a drive substrate (CMOS substrate) 22 and a plurality of micro mirrors (thin film mirrors) 23 (23A to 23F: 6 symbols are attached to the columns A to F). In this embodiment, for convenience of description, the number of micro mirrors 23 is set to 36 for description, but the actual number is hundreds of thousands or more. The micro-mirror 23 is formed in a square shape with a side length of about several ten μm. In the driving substrate 22, a plurality of pixel regions are arranged in a matrix, and CMOS SRAM cells are formed in each pixel region.

The micro mirror 23 is arranged on the driving substrate 22 corresponding to each CMOS SRAM cell. The micro mirror 23 is installed by MEMS (Micro Electro Mechanical Systems) technology. Each micro-mirror 23 is set to be movable at two positions. Specifically, it is configured to rotate at two positions, for example, an angle of +10 degrees and an angle of -10 degrees with respect to the substrate surface. The micro-mirror 23 corresponds to the output data from the CMOS SRAM cell side, and is driven by displacement at the above two positions.

As shown in FIG. 1, it is configured such that the laser beams LB are incident in batches from the laser light source unit 12 side at the plurality of micro mirrors 23 constituting the array. In addition, each of the micro mirrors 23 (23A to 23F) is set to reflect a part of the laser light of the laser beam LB in two directions by selectively moving at the above two positions. One of the two directions is the direction in which a part of the laser light of the laser beam LB is directed toward the baffle 19, and the other of the two directions is the laser light of a part of the laser beam LB The direction toward the surface of the substrate 1 to be processed.

In Figure 1, the laser light reflected from each micro mirror (23A1, 23A2, 23A3, 23A4, 23A5, 23A6) in a specific column of DMD 18 is divided into 6 laser beams LBd1, LBd2, LBd3 , LBd4, LBd5, LBd6 are shown schematically. In this embodiment, a row equipped with micro mirrors 23A1, 23A2, 23A3, 23A4, 23A5, 23A6 is used, but micro mirrors 23 in other rows may also be used.

The baffle 19 is configured to receive the reflection of the micro mirror 23 in the OFF state when the micro mirror 23 is in the OFF state (for example, the angle with respect to the drive substrate 22 is -10 degrees, the non-irradiation state) The position of the laser beam emitted.

For the microlens array 20, for example, a fly-eye lens can be used. The micro lens array 20 is set to reflect the laser beam LBd (LBd1 to LBd1 to LBd1 to LBd1 to LBd1 to LBd1 to LBd1 to LBd1 to LBd1 to LBd6, etc.), it is transmitted to the projection lens 21 while keeping the light beam independent. The projection lens 21 is set to image the introduced laser beam LBd (LBd1 to LBd6, etc.) on the surface of the substrate 1 to be processed while keeping the beam independent.

The control unit 14 controls the substrate conveying means (not shown) provided on the base 11, the laser light source unit 12, and the DMD 18. Specifically, the control unit 14 is set to drive and control the substrate transport means (not shown) to move the substrate 1 to be processed in the transport direction T at a specific speed. In addition, the control unit 14 is set so that the position detection means (not shown) is input with the position information of the planned modification area 6 (refer to FIGS. 4 to 6) in the substrate 1 to be processed.

In addition, the control unit 14 is set to drive and control the laser light source unit 12 and the laser beam irradiation unit 13 to perform the first irradiation and the second irradiation on the substrate 1 to be processed.

In the first irradiation, the control unit 14 emits pulsed laser light as the first laser light from the laser light source unit 12. In this embodiment, the output of the pulsed laser light is set to lower energy.

During the second irradiation, the control unit 14 continuously emits CW laser light as the second laser light from the laser light source unit 12. In this embodiment, the output of the CW laser light is set to be higher. It is set so that when the first and second irradiations are not performed, the laser light source unit 12 is turned off, or all the micro mirrors 23 (23A to 23F) in the DMD 18 are turned to the laser beam LB The OFF state of reflection toward the baffle 19.

The control unit 14 is set to output a driving signal to the DMD 18 when the planned reforming area 6 reaches a specific position relative to the base 11 based on the position information data of the planned reforming area 6. The DMD 18 to which the above-mentioned drive signal is input is controlled so that the micro mirrors 23 (for example, 23A1, 23A2, 23A3, 23A4, 23A5, and 23A6) of a specific column are turned on.

If the above-mentioned plural micro mirrors 23 are turned on, the laser beam LB, which is the pulsed laser light emitted from the laser light source unit 12, is controlled by these micro mirrors 23 (23A1, 23A2, 23A3, 23A4 , 23A5, 23A6) reflected and incident on the surface of the substrate 1 to be processed.

The laser beams LBd1, LBd2, LBd3, LBd4, LBd5, and LBd6 reflected from the micro mirrors 23 project the beam spot on a specific area (for example, the peripheral portion) of the planned modification area 6 (first Exposure). By performing the first irradiation on the amorphous silicon film 5, for example, as shown in Fig. 4, seed crystal regions 5A1, 5A2, 5A3, 5A4, 5A5, 5A6 etc. In addition, in this embodiment, in order to form these seed crystal regions 5A1, 5A2, 5A3, 5A4, 5A5, 5A6, etc., the energy of the microcrystallization conditions and the scanning speed of the substrate 1 to be processed are set.

In addition, the control unit 14 is set to drive and control the laser light source unit 12 and the laser beam irradiation unit 13 based on the above-mentioned position information, and to perform the second irradiation of the planned modification area 6. Specifically, the above-mentioned seed crystal regions 5A1, 5A2, 5A3, 5A4, 5A5, 5A6, etc. are used as starting points to project the beam spot of the CW laser light as the second laser light on the surface of the amorphous silicon film 5. After that, the trajectory of the beam spot is set so as to move around the area 6 to be modified. In addition, the method of moving the beam spot of the CW laser light so as to cover the modified area 6 by the second irradiation is described in the first embodiment and the second embodiment of the annealing method described later.

By this second irradiation, the amorphous silicon film 5 in the planned modification area 6 becomes a pseudo single crystal (hereinafter, also referred to as lateral crystal) silicon film 5B as a crystalline silicon film It is set as a condition. In the second irradiation, the control unit 14 is controlled so that the CW laser light oscillated from the CW laser light source 15 is directly and continuously irradiated from the light emitting unit 17 without passing through the pulse generator 16.

Figure 3 shows the region where the crystalline structure formed when the amorphous silicon film 5 is irradiated with laser light is satisfied. From the power density condition of the irradiated laser light, and the amorphous silicon film (substrate to be processed) ) Side of the view of the scanning speed conditions to show the mapping image. The laser annealing apparatus 10 of this embodiment is equipped with a memory means (not shown) that stores a map of the content as shown in FIG. 3. The control unit 14 refers to this map image at any time to perform the first irradiation and the second irradiation.

Specifically, the control unit 14 controls the scanning speed of the substrate 1 to be processed and the power density of the pulsed laser light PL (refer to FIG. 4) emitted from the laser light source unit 12 during the first irradiation. It becomes a condition for the establishment of the microcrystalline area in the map image shown in Figure 3. The control unit 14 controls the scanning speed of the substrate 1 to be processed and the power density of the CW laser light CWL (refer to Fig. 5) emitted from the laser light source unit 12 during the second irradiation as shown in Fig. 3. The conditions for the establishment of the lateral crystal (quasi-single crystal) region in the map image shown.

Although the configuration of the laser annealing device 10 of the present embodiment has been described above, the laser annealing device 10 is used to address the first and second embodiments of the laser annealing method and the associated methods. Action to illustrate.

(The first embodiment of laser annealing method) Figures 4 to 6 show the processes in the first embodiment of the laser annealing method using the laser annealing device 10 of this embodiment. First, in the laser annealing device 10, the substrate 1 to be processed is moved along the transport direction T at a specific scanning speed.

<The first irradiation process in the first embodiment of the laser annealing method> Figure 4 shows the project of the first irradiation. The control unit 14 of the laser annealing device 10 outputs a driving signal to the DMD 18 based on the position information of the planned reforming area 6 when the planned reforming area 6 reaches a specific position. According to the driving signal, the DMD 18 to which the above-mentioned driving signal is input turns the micro mirrors 23A1, 23A2, 23A3, 23A4, 23A5, and 23A6 into the ON state.

Fig. 4 shows that the plurality of micro mirrors 23A1, 23A2, 23A3, 23A4, 23A5, and 23A6 are in the ON state (the micro mirror 23 in the ON state is marked with diagonal lines). In this state, the laser beam LB formed by the pulsed laser light emitted from the laser light source unit 12 becomes the laser reflected by the micro mirrors 23A1, 23A2, 23A3, 23A4, 23A5, 23A6 Light beams LBd1, LBd2, LBd3, LBd4, LBd5, LBd6. These laser beams LBd1, LBd2, LBd3, LBd4, LBd5, LBd6 are pulsed laser beams PL shown in Fig. 4, and are incident on one side of the planned modification area 6 in a row (transport Near the edge on the downstream side in the direction T). As a result, as shown in FIG. 4, seed crystal regions 5A1, 5A2, 5A3, 5A4, 5A5, and 5A6 are formed along the downstream end edge in the conveying direction T of the planned modification region 6. These seed crystal regions 5A1, 5A2, 5A3, 5A4, 5A5, and 5A6 are those that change the amorphous silicon film 5 into microcrystalline silicon.

<The second irradiation process in the first embodiment of the laser annealing method> Figures 5 and 6 show the second irradiation project. Immediately after the completion of the above-mentioned first irradiation process, the control section 14 drives and controls the laser light source section 12 and the laser beam irradiation section 13 based on the position information of the planned modification area 6, and for the planned modification area 6 Start the second irradiation.

As shown in Figure 5, this second irradiation process uses the above-mentioned seed crystal regions 5A1, 5A2, 5A3, 5A4, 5A5, and 5A6 as the starting point to project the beam spot of the CW laser light CWL as the second laser light Annealing is performed on the surface of the amorphous silicon film 5. Figures 5 and 6 show the ON state of a plurality of micro mirrors 23A1, 23A2, 23A3, 23A4, 23A5, and 23A6 that are also used in the second irradiation (for the micro mirror 23 in the ON state, the grid is marked Slash) for display. At this time, the microcrystalline silicon system constituting the seed crystal regions 5A1, 5A2, 5A3, 5A4, 5A5, and 5A6 functions as a seed crystal to promote the pseudo-single crystal (lateral crystallization) of the amorphous silicon film 5, and can A good quality pseudo-single-crystal silicon film 5B is formed.

As shown in FIG. 6, the second irradiation is performed until the trajectory of the beam spot of each CW laser light CWL reaches the edge (one side) of the upstream side in the conveying direction T of the planned modification area 6. As a result, as shown in FIG. 6, the pseudo-single-crystal silicon film 5B can be grown so as to slightly cover the area 6 to be modified.

The pseudo-single-crystal silicon film 5B formed by this first laser annealing method is annealed from the downstream side to the upstream side in the conveying direction T with the seed regions 5A1, 5A2, 5A3, 5A4, 5A5, and 5A6 as the starting point . Therefore, in the formed pseudo-single-crystal silicon film 5B, there is a tendency that the degree of movement in the conveying direction T (electron movement) is greater than the degree of movement in the direction orthogonal to the conveying direction T. However, within the condition range of the mapped image shown in Fig. 3, for example, by selecting the power density or scanning speed in the second irradiation, a pseudo-single-crystal silicon with less directional dependence of mobility can be formed膜5B.

In addition, as shown in FIGS. 4 to 6, in the first embodiment of the laser annealing method, although the seed regions 5A1, 5A2, 5A3, 5A4, 5A5, and 5A6 are spaced apart from each other However, it can be set as a borderless seed crystal region by the size of the beam spot of the pulsed laser light PL or the arrangement density of the micro mirror 23, etc.

In addition, in FIGS. 5 and 6, for ease of explanation, the seed regions 5A1, 5A2, 5A3, 5A4, 5A5, and 5A6 are depicted in such a way that a large amount of them remain after the pseudo-single-crystal silicon film 5B is formed. . By setting these seed crystal regions 5A1, 5A2, 5A3, 5A4, 5A5, and 5A6 as the starting point for the second irradiation conditions, most of them can be pseudo-singly crystallized.

(The second embodiment of the laser annealing method) Figs. 7 to 9 show each process in the second embodiment of the laser annealing method using the laser annealing device 10 of this embodiment. First, in the laser annealing device 10, the substrate 1 to be processed is moved along the transport direction T at a specific scanning speed.

<The first irradiation process in the second embodiment of the laser annealing method> Figure 7 shows the first irradiation project. The control unit 14 of the laser annealing device 10 outputs a driving signal to the DMD 18 based on the position information of the planned reforming area 6 when the planned reforming area 6 reaches a specific position. According to the driving signal, the DMD 18 to which the above-mentioned driving signal is input turns ON only one micro-mirror 23A1 in the row set in advance.

Figure 7 shows that the micro mirror 23A1 is in the ON state (the micro mirror 23 in the ON state is marked with diagonal lines). In this state, the laser beam LB formed by the pulsed laser light emitted from the laser light source unit 12 becomes the laser beam LBd1 reflected by the micro mirror 23A1. The laser beam LBd1 is the pulsed laser beam PL shown in FIG. 7 and is incident on one of the corners of the planned modification area 6 (one end in the width direction on the downstream side in the conveying direction T). As a result, as shown in FIG. 7, seed crystal regions 5A1 are formed at the corners. Such crystal regions 5A1 are those obtained by changing the amorphous silicon film 5 into microcrystalline silicon.

<The second irradiation process in the second embodiment of the laser annealing method> Figures 8 and 9 show the second irradiation project. Immediately after the completion of the above-mentioned first irradiation process, the control section 14 drives and controls the laser light source section 12 and the laser beam irradiation section 13 based on the position information of the planned modification area 6, and for the planned modification area 6 Start the second irradiation.

As shown in Fig. 8, this second irradiation process is performed by projecting the beam spot of the CW laser light CWL as the second laser light on the surface of the amorphous silicon film 5 with the above-mentioned seed crystal region 5A1 as a starting point. annealing. Figures 8 and 9 show the ON state of any one of the plurality of micro mirrors 23A1, 23A2, 23A3, 23A4, 23A5, 23A6 used in the second irradiation as a column (for the ON state The micro-mirror 23 is marked with grid-shaped diagonal lines) for display. In addition, in Figure 8, the ON state is only the micro mirror 23A2, and in Figure 9, the ON state is only the micro mirror 23A6.

In this second irradiation, the seed crystal region 5A1 is used as a starting point to follow the width direction of one of the downstream sides of the conveying direction T, so that the CW from the micromirrors 23 adjacent to each other in sequence The laser beam CWL is gradually and continuously annealed in the width direction. That is, the micro mirrors 23A1, 23A2, 23A3, 23A4, 23A5, and 23A6 in a row are sequentially relayed in an ON state to perform the second irradiation along the width direction of the planned modification area 6.

As a result, by the CW laser light CWL, the amorphous silicon film 5 grows into a pseudo-single-crystal silicon film 5B. At this time, the movement of the laser beam of the CW laser light CWL is in the width direction of the modified area 6. Therefore, at this point, the movement degree in the width direction is greater than the movement degree in the conveying direction T.

After that, when the CW laser light CWL reaches the end of the planned modification area 6 in the width direction, the micro-mirror 23 is moved toward the other end of the planned modification area 6 in the width direction. The ON state is relayed in a chain. During this period, since the substrate 1 to be processed travels successively at a specific scanning speed, the beam spot of the CW laser light CWL moves relative to the upstream side of the conveying direction T successively.

In the second irradiation process of this turn-back, since there is an element that the beam spot of the CW laser light CWL also moves in the conveying direction T, the mobility of the pseudo-monocrystalline silicon film 5B grown by the second irradiation process is It also becomes larger in the conveying direction T. By causing this second irradiation to move in a zigzag-like manner covering the entire area 6 to be modified, a pseudo-single-crystal silicon film 5B with a small anisotropy of mobility and a high mobility can be obtained. As shown in FIG. 9, the second irradiation is continued until the trajectory of the beam spot of the CW laser light CWL reaches the edge portion on the upstream side in the conveying direction T of the planned modification area 6. As a result, it is possible to grow the pseudo-single-crystal silicon film 5B so as to cover the entire area within the planned modification area 6.

The pseudo-single-crystal silicon film 5B formed by the second embodiment of the laser annealing method uses the seed crystal region 5A1 as a starting point to grow while moving in a zigzag pattern. Therefore, it can be moved along the conveying direction. The degree of movement μ of T is formed so that the degree of movement in the direction orthogonal to the conveying direction T has the same value. Therefore, a channel layer region that can correspond to TFTs in all directions can be fabricated on the substrate 1 to be processed.

(Effects of the laser annealing device and laser annealing method of the first embodiment) Hereinafter, the effects of the laser annealing device 10 and the laser annealing method in the first aspect will be described.

In the laser annealing device 10 of the present embodiment, it is possible to perform the process of producing a seed crystal and the process of forming a pseudo-single-crystal silicon film 5B from the seed crystal as a starting point in a single device. .

In the laser annealing device 10 of this embodiment, the pseudo-monocrystalline silicon film and the polycrystalline silicon film can be selectively formed in the necessary area, and the number of manufacturing processes can be reduced to reduce the manufacturing cost, and the production tact time can be shortened.

In particular, in the laser annealing apparatus 10 of the present embodiment, since the CW laser light CWL is pulsed by the pulse generator 16 as the pulsed laser light PL, it can be used in one laser light source unit 12 The pulse laser light PL and the CW laser light CWL are realized, and there is a single device that smoothly performs the first irradiation process and the second irradiation process.

According to the laser annealing device 10 of the present embodiment, since the region 6 to be modified is the channel layer region of the TFT, the pseudo-single-crystal silicon film 5B formed by the second irradiation can be directly used as the channel layer region. Therefore, according to this embodiment, patterning processes such as photolithography process and wet etching process, and cleaning and cleaning processes after the patterning process are unnecessary, and the manufacturing process of the TFT substrate can be greatly reduced.

In the present embodiment, by using a row of seed crystal regions 5A (5A1, 5A2...) as a starting point in the first irradiation process, the laser beam of the CW laser light CWL is relative to the modified region 6 By relatively moving in the conveying direction T, a pseudo-single-crystal silicon film 5B that grows in one direction can be formed. In this case, by setting the conditions of the second irradiation, the anisotropy of the mobility can also be controlled to be small.

In this embodiment, in the first irradiation process, a seed crystal region 5A1 is used as a starting point to move the laser beam of the CW laser light CWL in a zigzag pattern relative to the modification planned region 6 to form a pseudo single crystal silicon In the film 5B, a good channel layer region with a further reduced anisotropy of mobility can be obtained by this.

In this embodiment, by using the DMD 18 as the spatial light modulator, only the ON and OFF actions of the micro mirror 23 are required to make the laser beam relative to the width direction of the modified area 6 The annealing is carried out in a gradual and continuous manner. Therefore, it is not necessary to move the substrate 1 to be processed in the width direction or to move the laser beam irradiation unit 13 in the width direction of the substrate 1 to be processed.

[Second Embodiment] Fig. 10 is a schematic configuration diagram of a laser annealing apparatus 10A according to the second embodiment of the present invention. This laser annealing device 10A is provided with a first laser light source unit 12A and a second laser light source unit 12B as a laser light source unit. The first laser light source unit 12A includes a pulsed laser light source 25 and a light emitting unit 26. The second laser light source unit 12B includes a CW laser light source 15 and a light emitting unit 17.

In the laser annealing device 10A of this embodiment, it is set so that the first irradiation process is performed using the first laser light source unit 12A, and the second irradiation process is performed using the second laser light source unit 12B. . The other configuration of the laser annealing apparatus 10A of this embodiment is the same as that of the laser annealing apparatus 10 of the above-mentioned first embodiment, so the description is omitted.

[Third Embodiment] Fig. 11 shows the important part of the laser annealing apparatus according to the third embodiment of the present invention. In the present embodiment, the DMD 18A is set from one of a pair of sides extending in a direction perpendicular to the conveying direction T of the planned modification area 6 (the downstream side of the conveying direction T) to the other (the conveying direction) T upstream side) and when the beam spot of the second laser beam is moved in the second irradiation process, the gap between the micro mirrors is not reflected, so that the laser beam from the micro mirror 24 The projections of are arranged densely in the planned modification area 6. In particular, in the DMD 18A shown in FIG. 11, by selecting the micro-mirrors shown by the symbol 24S, the projection of the laser beams from these micro-mirrors is dense in the modified region 6.

In this embodiment, the DMD 18A system is set to be able to rotate. In this embodiment, the projection lens 21 is also arranged between the DMD 18 and the amorphous silicon film 5. The DMD 18 is set to be rotatable around the optical axis or the vertical axis of the projection lens 21. Therefore, when the beam spot of the second laser light is moved, the DMD 18 can be directed so that the gap between the micro mirrors 23 is not reflected, so that the laser beam from the micro mirror 23 is projected The area is displaced in a direction in which the area 6 to be modified is dense. With the configuration as in this embodiment, the number of micro-mirrors 24 of DMD 18A is small, which is advantageous when the micro-mirrors 24 are spaced apart from each other. Moreover, by setting the DMD 18 to be displaceable in this way, the pitch of the micro mirror 23 in the direction perpendicular to the conveying direction (scanning direction) T can be switched according to the application. In addition, in the laser annealing apparatus 10 of the first embodiment, the DMD 18 may be configured to be rotationally displaced as in the present embodiment.

[Other embodiments] Although the above has been described with respect to the embodiment, the present invention is not limited by the statements and drawings that constitute a part of the disclosure of this embodiment. Obviously, the same industry can learn about various alternative implementation forms, embodiments, and application technologies based on this disclosure.

For example, in each of the above embodiments, although DMD 18 and 18A are used, as the spatial light modulator, liquid crystal cells with shutter function, grating light valve (GLV: Grating Light Valve, Silicon Registered trademark of Light Machines), Thin-film Micro mirror Array (TMA: Thin-film Micro mirror Array), etc.

Although the DMD 18 and 18A are used as the spatial light modulator in each of the above embodiments, the spatial light modulator may be used instead of the spatial light modulator and other beam moving means for moving the laser beam may be used.

In each of the above-mentioned embodiments, the substrate 1 to be processed is configured to move, but of course, the position of the substrate to be processed 1 is fixed and the laser beam irradiation unit 13 is moved.

In the first embodiment described above, the pulse generator 16 is used to generate the pulsed laser light PL. However, it is also possible to make the micromirror 23 vibrate at a high speed for pulse width modulation, which is suitable for the first Low energy density for irradiation engineering.

In each of the above-mentioned embodiments, the pseudo-single-crystal silicon film 5B is formed as the crystalline silicon film, but of course, it may be a structure in which the polycrystalline silicon film is grown from the seed crystal region. In this case, the seed crystal region can also be used as a starting point to form a good polysilicon film. In addition, as the second laser light for forming the polysilicon film, excimer laser light oscillated from the ELA device can also be used.

CWL: CW laser light LB: Laser beam PL: Pulsed laser light T: Transport direction W: width size 1: substrate to be processed 2: glass substrate 3: Gate wiring 4: Gate insulating film 5: Amorphous silicon film 5A1, 5A2, 5A3, 5A4, 5A5, 5A6: seed crystal area 5B: pseudo-single crystal silicon (crystalline silicon) film 6: Modify the scheduled area 10, 10A: Laser annealing device 11: Abutment 12: Laser light source department 12A: The first laser light source section 12B: The second laser light source section 13: Laser beam irradiation part 14: Control Department 15: CW laser light source 16: Pulse generator 17: Light emitting part 18: Digital micro mirror device (DMD, spatial light modulator) 19: bezel 20: Micro lens array 21: Projection lens 22: Drive substrate 23A1~6: Micro mirror 24, 24S: Micro mirror 25: Pulse laser light source 26: Light emitting part

[Figure 1] Figure 1 is a schematic configuration diagram of the laser annealing apparatus according to the first embodiment of the present invention. [Fig. 2] Fig. 2 is an explanatory diagram schematically showing an arrangement example of the micro-mirror in the laser annealing apparatus according to the first embodiment of the present invention. [Figure 3] Figure 3 shows the region where the crystal structure formed when the amorphous silicon film is irradiated with laser light is established. From the power density conditions of the irradiated laser light, and the amorphous silicon film (by From the viewpoint of the scanning speed condition on the processing substrate) side, the map image is displayed. [Fig. 4] Fig. 4 shows the process of forming the seed crystal region in the first embodiment of the laser annealing method using the laser annealing device according to the first embodiment of the present invention. Illustration. [Fig. 5] Fig. 5 is a diagram showing the species formed in the first irradiation process in the first embodiment of the laser annealing method using the laser annealing device according to the first embodiment of the present invention This is an explanatory diagram showing the process where the crystal region becomes the starting point for the second irradiation. [FIG. 6] FIG. 6 is a diagram of the first embodiment of the laser annealing method using the laser annealing device according to the first embodiment of the present invention, which is scheduled to be modified by the second irradiation process The area is completely modified into a pseudo-single-crystal silicon film state for illustration. [Figure 7] Figure 7 shows the process of forming the seed crystal region in the first irradiation process in the second embodiment of the laser annealing method using the laser annealing device of the first embodiment of the present invention Illustration. [Fig. 8] Fig. 8 is a diagram showing the species formed in the first irradiation process in the second embodiment of the laser annealing method using the laser annealing device of the first embodiment of the present invention This is an explanatory diagram showing the process where the crystal region becomes the starting point for the second irradiation. [Fig. 9] Fig. 9 is a diagram of the second embodiment of the laser annealing method using the laser annealing device according to the first embodiment of the present invention. The modification is scheduled by the second irradiation process. The area is completely modified into a pseudo-single-crystal silicon film state for illustration. [Figure 10] Figure 10 is a schematic configuration diagram of a laser annealing apparatus according to a second embodiment of the present invention. [FIG. 11] FIG. 11 shows how the beam spot selectively irradiated from the digital micro-mirror device is compared with the target area for modification in the laser annealing apparatus of the third embodiment of the present invention. The projection area of the laser beam and the configuration state of the digital micro-mirror device when moving relatively is an explanatory diagram for conceptual display.

LB: Laser beam

LBd1~LBd6: Laser beam

1: substrate to be processed

2: glass substrate

3: Gate wiring

4: Gate insulating film

5: Amorphous silicon film

10: Laser annealing device

11: Abutment

12: Laser light source department

13: Laser beam irradiation part

14: Control Department

15: CW laser light source

16: Pulse generator

17: Light emitting part

18: Digital micro mirror device (DMD, spatial light modulator)

19: bezel

20: Micro lens array

21: Projection lens

22: Drive substrate

23A1~6: Micro mirror

Claims (22)

A laser annealing device, which irradiates a laser beam to a modified region for modifying an amorphous silicon film to grow a crystalline silicon film in the modified region for modification, This laser annealing device is provided with a laser light source unit that oscillates the first laser light and the second laser light, and The laser beam irradiation section selectively irradiates the surface of the amorphous silicon film with laser light oscillated from the laser light source section, The laser annealing device performs: first irradiation, irradiating the amorphous silicon film with the first laser light oscillated from the laser light source unit to form a seed crystal region, and In the second irradiation, the second laser light oscillated from the laser light source unit uses the seed crystal region as a starting point to irradiate the beam spot of the second laser light to the surface of the amorphous silicon film. The movement is carried out by covering the predetermined region for modification, and the modification is performed so that the amorphous silicon film in the predetermined region for modification becomes the crystalline silicon film. The laser annealing device described in claim 1, wherein: The aforementioned predetermined region for modification is the channel layer region of the thin film transistor. Such as the laser annealing device described in claim 1 or 2, in which: The first irradiation is the amount of energy that is set to make the amorphous silicon film as a seed crystal for micro-crystallization conditions, The aforementioned second laser light is a continuous oscillation laser light, and the aforementioned second irradiation is continuous irradiation of a continuous oscillation laser light. Such as the laser annealing device described in any one of claim 1 to claim 3, wherein: The laser light source unit is provided with a light source that oscillates continuous oscillating laser light. During the first irradiation, the laser light continuously oscillated from the light source is pulsed to oscillate the first laser light. 2 During irradiation, the continuous oscillation laser light oscillated from the aforementioned light source is directly oscillated. Such as the laser annealing device described in any one of claim 1 to claim 3, wherein: The aforementioned laser light source unit has different light sources, The first irradiation and the second irradiation use different light sources. Such as the laser annealing device described in any one of claim 1 to claim 5, wherein: The aforementioned predetermined area for modification is rectangular, The first irradiation is to form a row of the seed crystal regions along one of a pair of parallel sides in the predetermined region for modification. The second irradiation is to move the beam spot of the second laser light toward the other side of the pair of sides facing each other in the predetermined modification area with the seed crystal region in the row as a starting point . Such as the laser annealing device described in any one of claim 1 to claim 5, wherein: The aforementioned predetermined area for modification is rectangular, The first irradiation is to form the seed crystal region at a corner of the predetermined region for modification, The second irradiation uses the seed crystal region formed at the corner as a starting point to make the beam spot of the second laser light start from the side including the one corner to the side including the one corner. It moves in a zigzag pattern until the other side of a pair of sides that become parallel to each other. Such as the laser annealing device described in any one of claim 1 to claim 7, wherein: The laser beam irradiating part is equipped with a spatial light modulator which selectively reflects the laser light oscillated from the laser light source part, and selects the area within the predetermined modification area Irradiate the laser beam sexually. The laser annealing device as described in claim 8, wherein: In the aforementioned spatial light modulator, a plurality of micro-mirrors are arranged in a matrix, and each of the micro-mirrors can be individually switched to the laser beam irradiation state on the surface of the amorphous silicon film And the non-irradiation state is selected and driven. The laser annealing device described in claim 9, wherein: A projection lens is arranged between the spatial light modulator and the amorphous silicon film, The aforementioned spatial light modulator is set to be rotatable around the optical axis or the vertical axis of the aforementioned projection lens, When the beam spot of the second laser light is moved, the space between the micro mirrors can not be reflected, and the spatial light modulator can be directed so that the laser from the micro mirrors The projection area of the light beam is displaced in a direction in which the predetermined modification area becomes dense. Such as the laser annealing device described in any one of claim 1 to claim 10, wherein: The aforementioned crystalline silicon film is selected from polycrystalline silicon films and pseudo-monocrystalline silicon films. A laser annealing method is to irradiate a laser light on a predetermined area to be modified to modify an amorphous silicon film to grow a crystalline silicon film in the predetermined area to be modified, The laser annealing method includes: a first irradiation process of irradiating the aforementioned amorphous silicon film with a first laser light for forming a seed crystal region, and The second irradiation process is to move the beam spot of the second laser light to cover the predetermined area of modification and irradiate the surface of the amorphous silicon film with the seed crystal region as the starting point. The amorphous silicon film in the predetermined region for modification is modified in such a way that the amorphous silicon film becomes the crystalline silicon film. The laser annealing method as described in claim 12, wherein: The aforementioned predetermined region for modification is the channel layer region of the thin film transistor. Such as the laser annealing method described in claim 12 or claim 13, wherein: The amount of irradiation energy in the irradiation of the first laser light in the first irradiation process is set to the condition that the amorphous silicon film is used as a seed crystal for micro-crystallization, The irradiation of the second laser light in the second irradiation process is continuous irradiation using continuous oscillation laser light. As the laser annealing method described in claim 14, wherein: The continuous oscillation laser light used in the second irradiation process is pulsed and irradiated as the first laser light. Such as the laser annealing method described in any one of claim 12 to claim 14, wherein: In the first irradiation process and the second irradiation process, different light sources are used. Such as the laser annealing method described in any one of claim 12 to claim 16, wherein: The aforementioned predetermined area for modification is rectangular, In the aforementioned first irradiation process, a row of the aforementioned seed crystal regions is formed along one of a pair of parallel sides in the aforementioned modified region, In the second irradiation process, the seed crystal region in the row is used as a starting point, and the second laser beam is directed toward the other of the pair of sides facing each other in the predetermined modification region. The beam spot moves. Such as the laser annealing method described in any one of claim 12 to claim 16, wherein: The aforementioned predetermined area for modification is rectangular, In the first irradiation process, the seed crystal region is formed at a corner of the predetermined region for modification, In the second irradiation process, the seed crystal region formed at the corner portion is used as a starting point to make the beam spot of the second laser light start from the side including the one corner portion up to and including the one corner portion. The sides of the corners move in a zigzag manner until they become parallel to the other side of the pair of sides. Such as the laser annealing method described in any one of claim 12 to claim 18, wherein: The first irradiation process and the second irradiation process are performed by using a spatial light modulator, which selectively reflects laser light and selectively irradiates the predetermined region for modification Laser beam. The laser annealing method as described in claim 19, wherein: In the aforementioned spatial light modulator, a plurality of micro-mirrors are arranged in a matrix, and each of the micro-mirrors can be individually switched to the laser beam irradiation state on the surface of the amorphous silicon film And the non-irradiation state is selected and driven. The laser annealing method described in claim 20, wherein: The aforementioned spatial light modulator is relative to the aforementioned modified area, When the beam spot of the second laser light is moved, the gap between the micro-mirrors is not reflected, so that the projection area of the laser beam from the micro-mirror is modified in the aforementioned modification. It is arranged in a dense direction in a predetermined area. Such as the laser annealing method described in any one of claim 12 to claim 21, wherein: The aforementioned crystalline silicon film is selected from polycrystalline silicon films and pseudo-monocrystalline silicon films.

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