TWI400747B - Laser irradiation method and device - Google Patents

Description

Laser irradiation method and device

The present invention relates to a laser irradiation method and apparatus. In particular, the laser irradiation method and apparatus are related to a processing pattern in which laser irradiation can be performed and the processed substrate after the laser irradiation is not streaked.

In the prior art, a conventional semiconductor device is manufactured by scanning a light beam in a short-axis direction of a strip-shaped irradiation region while irradiating a light beam having a strip-shaped irradiation region on a substrate to be processed, while simultaneously The strip-shaped irradiation region is vibrated in the longitudinal direction of the strip-shaped irradiation region (see, for example, Patent Document 1).

[Patent Document 1] Japanese Patent Special Publication No. 04-10216

In the above prior art, since the strip-shaped irradiation region is vibrated at a certain frequency (for example, 1 kHz) in the long-axis direction, in the long-axis direction of the strip-shaped irradiation region, in terms of the change in the position of the strip-shaped irradiation region , become a regular change.

However, when the positional change in the long-axis direction of the strip-shaped irradiation region becomes a rule, a stripe-like treatment pattern appears on the substrate to be processed after the treatment, and in a serious case, even a stripe which can be discerned is formed, which becomes a problem. point.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a laser irradiation method and apparatus which can perform laser irradiation and which does not cause a stripe-like processing pattern on a substrate to be processed after laser irradiation.

In a first aspect, the present invention provides a laser irradiation method in which a strip-shaped irradiation region (6) for irradiating laser light is formed on a semiconductor substrate (S); and a long axis of a strip-shaped irradiation region (6) is simultaneously provided. The position of the strip-shaped irradiation region (6) is changed in the direction, and the semiconductor substrate (S) is moved in the short-axis direction of the strip-shaped irradiation region (6), such that the laser irradiation method is characterized in that: At least one of the position in the long axis direction of the shaped irradiation region (6) and the position change timing is irregular.

In the laser irradiation method according to the first aspect, the position of the strip-shaped irradiation region (6) is simultaneously changed in the longitudinal direction of the laser beam-shaped irradiation region (6), and the laser beam is irradiated to the position. Irregularly changing; or making each position a fixed position in several different places, but making the timing of the change of the position change irregularly; or making the irregularity of the position and the timing of changing the position are irregular changes. According to this aspect, the irregularity of at least one of the timings of the position and the change position causes the stripe-like processing pattern to not appear on the substrate to be processed after the laser irradiation.

According to a second aspect of the present invention, in the laser irradiation method of the first aspect, the position of the strip-shaped irradiation region (6) is two or more, and the steps are sequentially selected. One of these locations and makes the selection timing random.

In the laser irradiation method according to the second aspect described above, the position of the strip-shaped irradiation region (6) is changed while the longitudinal direction of the strip-shaped irradiation region (6) of the laser light is changed, and the laser beam is irradiated. It is a fixed position for a plurality of different places but the position change timing is irregularly changed. In this way, the processed substrate after the laser irradiation does not have a stripe-like processing pattern.

According to a third aspect of the present invention, in the laser irradiation method of the second aspect, the laser light irradiation is performed in a pulse shape in the pulse wave. The position of the strip-shaped irradiation region (6) is changed at intervals randomly selected between 1 and 16 times the interval.

In the laser irradiation method according to the third aspect described above, the position change timing can be made substantially irregular.

According to a fourth aspect of the present invention, in the laser irradiation method of the first aspect, the position of the strip-shaped irradiation region (6) is set to five or more positions, and is randomly selected. One of these positions, and the selection timing can be fixed or random.

In the laser irradiation method according to the fourth aspect described above, the position of the strip-shaped irradiation region (6) is simultaneously changed in the longitudinal direction of the strip-shaped irradiation region (6) of the laser light, and laser irradiation is performed thereon. This position is a fixed position of five or more positions, and the position selection from among them is irregularly changed. According to this aspect, if the position is substantially irregular, the processed substrate after the laser irradiation does not have a stripe-like processing pattern.

According to a fifth aspect of the present invention, in the laser irradiation method of the fourth aspect, the laser light irradiation is performed in a pulse wave manner, and the band is changed for each pulse wave. The position of the illuminated area (6).

In the laser irradiation method according to the fifth aspect described above, since the timing of the position change is fixed, the control becomes easy.

According to a sixth aspect of the present invention, in the laser irradiation method of the fourth aspect, the laser light irradiation is performed in a pulse wave manner at a pulse wave interval of 1 The position of the above-mentioned strip-shaped irradiation region (6) is changed by an interval of a random selection of 16 times.

In the laser irradiation method according to the sixth aspect described above, the position change timing can be made substantially irregular.

In a seventh aspect, the present invention provides a laser irradiation apparatus (100), characterized by comprising: a laser oscillator (1) for outputting laser light (A); and an optical element (2) for inputting the above Laser light (A), and the position of the output laser light (B1, B2) can be changed at two or more positions; the optical system (3, 4) causes the position of the laser light (B1, B2) to change direction The long axis direction of the strip-shaped irradiation region (6), the laser light (B1, B2) is shaped on the strip-shaped irradiation region to be irradiated onto the semiconductor substrate (S), and the mobile station (5) is used to hold the semiconductor a substrate (S) movable in a short axis direction of the strip-shaped irradiation region (6); a switching means (10) for sequentially selecting and switching one of the laser light (B1, B2); and switching timing control Means (8) is used to make the above switching timing random.

The laser irradiation device (100) according to the seventh aspect described above is suitable for the laser irradiation method for performing the second aspect described above.

According to a seventh aspect of the invention, in the laser irradiation apparatus of the seventh aspect, the laser oscillator (1) outputs laser light in a pulse wave shape; and the switching timing The control means (8) is an interval at which the pulse wave interval of the laser light is randomly selected from 1 to 16 times, and becomes the timing of the switching.

The laser irradiation apparatus (100) according to the eighth aspect described above is suitable for the laser irradiation method for implementing the third aspect described above.

According to a ninth aspect, a laser irradiation apparatus (200) according to the present invention is characterized by comprising: a laser oscillator (1) for outputting laser light (A); and an optical element (2) for inputting The above-mentioned laser light (B1), and the position of the output laser light (B1 to B5) can be changed at five or more positions; the optical system (3, 4) changes the position of the above-mentioned laser light (B1 to B5) The direction is the long axis direction of the strip-shaped irradiation region (6), and the laser light (B1 to B5) is shaped in the strip-shaped irradiation region to be irradiated onto the semiconductor substrate (S); and the moving table (5) is used to hold the above a semiconductor substrate (S) movable in a short axis direction of the strip-shaped irradiation region (6); a switching means (10) for randomly selecting and switching one of the laser light (B1 to B5); and switching timing The control means (8) is used to make the switching timing described above fixed or random.

The laser irradiation device (100) according to the ninth aspect is suitable for the laser irradiation method for carrying out the fourth aspect.

According to a tenth aspect, in the laser irradiation apparatus of the seventh aspect, the laser oscillator (1) outputs laser light in a pulse waveform, and the switching timing control The means (8) is such that the interval between the pulse waves of the laser light is the same as the timing of the switching.

The laser irradiation apparatus (100) of the tenth aspect is suitable for the laser irradiation method for implementing the above fifth aspect.

According to a seventh aspect of the invention, in the laser irradiation apparatus of the seventh aspect, the laser oscillator (1) outputs laser light in a pulse waveform, and the switching timing The control means (8) is a timing at which the switching is randomly selected between 1 and 16 times the pulse interval of the laser light.

The laser irradiation device (100) according to the eleventh aspect is suitable for the laser irradiation method for carrying out the sixth aspect.

According to a thirteenth aspect, in the laser irradiation apparatus of any one of the seventh to eleventh aspect, the optical element (2) is an acousto-optic deflector.

In the laser irradiation apparatus (100) of the above-described twelfth aspect, since the acousto-optic deflector as the optical element (2) is used, when it is equivalent to the XY stage of the prior art, the mobile station (5) or the previous When the carbon heater of the technology is compared with the case where the laser oscillator (1) or the optical system (3) is moved, the position control can be performed at a high speed.

According to the laser irradiation method and apparatus of the present invention, at least one of the timings of the position and the changed position is made irregular, so that the processed substrate after the laser irradiation does not have a stripe-like processing pattern. That is, it is possible to suppress uneven illumination due to regular vibration of the strip-shaped irradiation region in the longitudinal direction thereof.

The present invention will now be described in more detail by way of embodiments shown in the drawings. In addition, the description herein is not intended to limit the invention.

[Example 1]

1 is a configuration explanatory view showing a laser irradiation apparatus 100 of Embodiment 1.

The laser irradiation apparatus 100 includes a laser oscillator 1 that outputs laser light in response to a pulse wave T, and an acousto-optic deflector (AOD element) 2 for changing the input laser light A. Output direction; homogenizer optical system 3 and p-lens 4, such that the direction of change of the position of the laser beam B1 or B2 output from the AOD element 2 becomes the long-axis direction of the strip-shaped illumination region 6, in which the strip-shaped illumination region 6 pairs of the laser light B1 or B2 are shaped and irradiated on the semiconductor substrate S; the mobile station 5 is used to hold the semiconductor substrate S and move it in the short-axis direction of the strip-shaped illumination region 6; the laser oscillation triggers the pulse wave a generator 7 for outputting a trigger pulse T at intervals of, for example, 250 μs; switching the timing control circuit 8 between 1 and 16 times the pulse interval of the trigger pulse T, at a randomly selected interval, The switching pulse wave t is output; the first AOD element drives the pulse wave generator 91, and outputs a first deflection pulse b1 for causing the laser light output from the AOD element 2 to be in the direction of the laser light B1; and the second AOD element driving the pulse wave a generator 92 for outputting the second biasing pulse b2 to output the lightning from the AOD element 2 Light becomes a direction of the laser beam B1; and, a switching circuit 10, the switching pulse t corresponding to the first pulse toward b1 and the second switch alternately deflecting the pulse wave b2, which is inputted to the AOD element 2.

2 is a timing chart for explaining the trigger pulse wave T, the switching pulse wave t during the output of the laser light, and the positional change of the strip-shaped irradiation region 6.

The interval τ of the trigger pulse T is a fixed value of, for example, 250 μs.

The laser light is synchronized with the trigger pulse wave T, for example, in the form of a pulse wave having a pulse wave amplitude of W = 125 μs.

The switching pulse wave t is output in synchronization with the stop of the laser light. The interval K of the switching pulse t is randomly selected, for example, 250 μs, 500 μs, 750 μs, ..., 3750 μs, 4000 μs.

The position of the strip-shaped irradiation region 6 alternately becomes B1 or B2, but since the interval K of the switching is substantially irregular, the time of irradiation at the position B1 or B2 becomes irregular.

According to the laser irradiation apparatus 100 of the first embodiment, the position of the strip-shaped irradiation region 6 is simultaneously changed in the longitudinal direction of the strip-shaped irradiation region 6, and laser irradiation is performed. The position of the strip-shaped irradiation area 6 is fixed at two positions of B1 and B2, but the timing of the switching position can also be changed irregularly. In this manner, the processed substrate S after the laser irradiation does not have a stripe-like processing pattern. In addition, since the position switching is performed using the AOD element 2, it is possible to switch at a high speed.

Further, in the above description, the position is fixed at two positions B1 and B2, but the position may be three or more, and the positions may be sequentially switched.

[Embodiment 2]

Fig. 3 is a structural explanatory view showing the laser irradiation apparatus 200 of the second embodiment.

The laser irradiation device 200 includes a laser oscillator 1 that outputs laser light in a pulse wave type corresponding to the trigger pulse wave T, and an AOD element (acoustic light deflector) 2 for changing the input laser light A. The output direction; the homogenizer optical system 3 and the p-lens 4, the direction of the change of the position of the laser light B1 to B5 output from the AOD element 2 becomes the long-axis direction of the strip-shaped irradiation region 6, in which the strip-shaped irradiation region 6 pairs of laser light B1~B5 are shaped and irradiated on the semiconductor substrate S; the mobile station 5 is used to hold the semiconductor substrate S and move it in the short axis direction of the strip-shaped illumination region 6; the laser oscillation triggers the pulse wave The generator 7 is configured to output a trigger pulse T at an interval of, for example, 250 μs; and switch the timing control circuit 8 to output a switching pulse t at the same interval K as the pulse wave interval of the trigger pulse T; The fifth AOD element drives the pulse wave generators 91 to 95 for outputting the first to fifth deflection pulses b1 to b5, so that the laser light output from the AOD element 2 becomes the direction of the laser light B1 to B5; and, switching The circuit 10 randomly selects any one of the first to fifth deflection pulses b1 to b5 corresponding to the switching pulse wave t, and inputs it to AOD component 2.

4 is a timing chart for explaining the trigger pulse wave T, the switching pulse wave t during the output of the laser light, and the positional change of the strip-shaped irradiation region 6.

The interval τ of the trigger pulse T is a fixed value of, for example, 250 μs.

The laser light is synchronized with the trigger pulse wave T, for example, in the form of a pulse wave having a pulse wave amplitude of W = 125 μs.

The switching pulse wave t is output in synchronization with the stop of the laser light. The interval K of the switching pulse t is, for example, 250 μs.

The position of the strip-shaped irradiation area 6 is any one of B1 to B5 which is irregularly selected. Therefore, the time of irradiation at each of the irradiation positions B1 to B5 is fixed, but it is irregular at which position to illuminate.

According to the laser irradiation apparatus 200 of the second embodiment, the position of the strip-shaped irradiation region 6 is simultaneously changed in the longitudinal direction of the strip-shaped irradiation region 6, and laser irradiation is performed. The position of the strip-shaped irradiation region 6 is any one of B1 to B5, and the irradiation time at each position is fixed. However, since the position becomes irregular, the processed substrate S after the laser irradiation does not have a stripe-like processing pattern. In addition, since the position switching is performed using the AOD element 2, it is possible to switch at a high speed.

[Example 3]

In the laser irradiation apparatus 200 of the second embodiment, the switching timing control circuit 8 of the first embodiment can also be used.

According to the laser irradiation apparatus of the third embodiment, the laser irradiation is performed while changing the position of the strip-shaped irradiation region 6 in the longitudinal direction of the strip-shaped irradiation region 6. The position of the strip-shaped irradiation area 6 is any one of B1 to B5, but which position becomes irregular. In addition, the irradiation time at each position is also irregular. Therefore, the processed substrate S after the laser irradiation does not have a stripe-like processing pattern. In addition, since the position switching is performed using the AOD element 2, it is possible to switch at a high speed.

(industrial availability)

The laser irradiation method and apparatus of the present invention can be utilized, for example, in the fabrication or activation of a semiconductor layer.

1. . . Laser oscillator

2. . . AOD component

3. . . Homogenizer optical system

4. . . P-lens

5. . . Mobile station

6. . . Ribbon irradiation area

7. . . Laser oscillation trigger pulse generator

8. . . Switching timing control circuit

10. . . Switching circuit

91~95. . . AOD component driven pulse generator

100, 200. . . Laser irradiation device

A, B1~B5. . . Laser light (location)

B1. . . First bias pulse

B2. . . Second bias pulse

B3~b5. . . Biased pulse

S. . . Substrate to be processed (semiconductor substrate)

T. . . Trigger pulse

t. . . Switching pulse

Fig. 1 is a structural explanatory view of a laser irradiation apparatus of a first embodiment.

Fig. 2 is a timing chart showing the operation of the laser irradiation apparatus of the first embodiment.

Fig. 3 is a structural explanatory view of a laser irradiation apparatus of a second embodiment;

Fig. 4 is a timing chart showing the operation of the laser irradiation apparatus of the second embodiment.

1. . . Laser oscillator

2. . . AOD component

3. . . Homogenizer optical system

4. . . P-lens

5. . . Mobile station

6. . . Ribbon irradiation area

7. . . Laser oscillation trigger pulse generator

8. . . Switching timing control circuit

91, 92. . . AOD component driven pulse generator

100. . . Laser irradiation device

A, B1, B2. . . Laser light (location)

B1. . . First bias pulse

B2. . . Second bias pulse

S. . . Substrate to be processed

Claims (12)

A laser irradiation method is characterized in that a strip-shaped irradiation region (6) for irradiating laser light is formed on a semiconductor substrate (S); and a strip-shaped irradiation region is changed in a long-axis direction of the strip-shaped irradiation region (6) (6) a position where the semiconductor substrate (S) is moved in the short-axis direction of the strip-shaped irradiation region (6), such as a laser irradiation method; characterized in that the long axis of the strip-shaped irradiation region (6) is implemented The position of the direction becomes irregular, or at least one of the intervals of the changed positions becomes irregular. In the laser irradiation method according to the first aspect of the invention, the position of the strip-shaped irradiation region (6) is two or more, and one of the positions is sequentially selected, and the selection timing is made random. The laser irradiation method of claim 2, wherein the laser light irradiation is performed in a pulse shape, and the interval is randomly selected between 1 and 16 times of the pulse wave interval. The position of the strip-shaped illumination area (6). The laser irradiation method of claim 1, wherein the position of the strip-shaped irradiation area (6) is five or more positions, and one of the positions is randomly selected, and the selection timing may be fixed or random. The laser irradiation method of claim 4, wherein the laser light irradiation is performed in a pulse wave shape, and the position of the strip-shaped irradiation region (6) is changed for each pulse wave. The laser irradiation method of claim 4, wherein the irradiation of the laser light is performed in a pulse wave manner, and the strip shape is changed at intervals randomly selected between 1 and 16 times of the pulse wave interval. Irradiation area (6) The location. A laser irradiation device (100), comprising: a laser oscillator (1) for outputting laser light (A); and an optical element (2) for inputting the laser light (A) and The position of the output laser light (B1, B2) can be changed at two or more positions; the optical system (3, 4) causes the position of the laser light (B1, B2) to change into a strip-shaped illumination area (6) In the long axis direction, the laser light (B1, B2) is shaped in the strip-shaped irradiation region to be irradiated onto the semiconductor substrate (S), and the mobile station (5) is used to hold the semiconductor substrate (S). The short-axis direction movement of the strip-shaped irradiation region (6); switching means (10) for sequentially selecting and switching one of the laser light (B1, B2); and switching timing control means (8) for making The timing of the above switching is random. The laser irradiation device of claim 7, wherein the laser oscillator (1) outputs laser light in a pulse wave shape; and the switching timing control means (8) is to separate the pulse wave of the laser light. The interval of random selection between 1 and 16 times becomes the timing of the above switching. A laser irradiation device (200), characterized by comprising: a laser oscillator (1) for outputting laser light (A); and an optical element (2) for inputting the above-mentioned laser light (B1) and The position of the output laser light (B1~B5) can be changed at five or more positions; the optical system (3, 4) causes the position of the laser light (B1~B5) to change into a strip-shaped illumination area (6) In the long axis direction, the laser light (B1 to B5) is shaped in the strip-shaped irradiation region to be irradiated onto the semiconductor substrate (S), and the mobile station (5) is used to hold the semiconductor substrate (S). The short-axis direction of the strip-shaped irradiation region (6) is moved; The switching means (10) is for randomly selecting and switching one of the laser lights (B1 to B5); and switching the timing control means (8) for making the switching timing described above fixed or random. The laser irradiation device of claim 7, wherein the laser oscillator (1) outputs laser light in a pulse wave shape, and the switching timing control means (8) is a pulse wave of the laser light The interval of the same interval becomes the timing of the above switching. The laser irradiation device of claim 7, wherein the laser oscillator (1) outputs laser light in a pulse wave shape, and the switching timing control means (8) is configured to cause a pulse wave interval in the laser light. The interval of random selection between 1 and 16 times becomes the timing of the above switching. A laser irradiation apparatus according to any one of claims 7 to 11, wherein the optical element (2) is an acousto-optic deflector.