KR20080109788A - Laser irradiation device - Google Patents

Abstract

Provided is a laser irradiation device, which can perform such a position control easily as to move a band-shaped irradiation area at a high speed in the long axis direction. A rotary polygon mirror (2) is rotated at a constant speed. A timing control circuit (8) outputs, on the basis of rotational phase information (Q) from an encoder (7), a trigger (G) at an output timing varying within a predetermined time range. A laser oscillator (1) outputs a laser beam (B1) in response to the trigger (G). The rotary polygon mirror (2) may be rotated once for a time period of mirror times as long as an average time interval, at which the laser oscillator (1) outputs the laser beam (B1) in pulses, so that the rotation can be easily executed. The timing control, in which the laser beam (B1) is outputted in pulses by the laser oscillator (1), is shorter than the average time interval, but can be easily executed, because of no moving part. Thus, the position of a band-shaped irradiation area (4) can be easily moved at a high speed within the predetermined range of the band-shaped irradiation area (4) in the long axis direction. ® KIPO & WIPO 2009

Description

Laser irradiation device {LASER IRRADIATION DEVICE}

TECHNICAL FIELD The present invention relates to a laser irradiation apparatus, and more particularly, to a laser irradiation apparatus capable of easily performing position control of moving a strip-shaped irradiation region at high speed in the major axis direction.

Conventionally, when irradiating a light beam having a band-shaped irradiation area to a substrate to be processed, the beam beam is scanned in a short axis direction of the band-shaped irradiation area while being in the long axis direction of the band-shaped irradiation area. The manufacturing method of the semiconductor device which vibrates a strip | belt-shaped irradiation area is known (for example, refer patent document 1).

Patent Document 1: Japanese Patent Application Laid-Open No. 04-10216

In the above prior art, in order to vibrate the strip-shaped irradiation area in the major axis direction, the XY stage or the carbon heater holding and holding the substrate to be processed is moved.

However, since the XY stage or the carbon heater has a large mass, there is a problem that the response is slow and it is difficult to control the position at high speed.

Then, the objective of this invention is providing the laser irradiation apparatus which can perform the position control which moves a strip | belt-shaped irradiation area | region at high speed in a long axis direction easily.

In a first aspect, the present invention provides a laser oscillator 1 that pulses a laser beam B1, a reflector 2 that reflects the laser beam B1, and the laser beam B1 is incident. A strip-shaped irradiation area having the long axis direction in which the reflection beam B2 moves due to a change in the angle θ or the position of the reflection surface 2b of the reflector 2 to the laser beam B1. The optical system 3 for forming the reflective beam B2 at 4) and irradiating the semiconductor substrate S and the semiconductor substrate S may be protected and moved in the short axis direction of the band-shaped irradiation region 4. The movable table 5, the reflector drive means 6 for changing the angle or position of the reflector 2, and the laser to change the position of the strip-shaped irradiation area within a predetermined range of the major axis direction of the strip-shaped irradiation area. Timing of pulse output of the laser beam B1 to the oscillator 1 and the half-time driving number A stage 6 is provided with a timing control means 8 which adjusts the timing which changes the angle or position of the said reflector 2, The laser irradiation apparatus 1 characterized by the above-mentioned.

In the laser irradiation apparatus 100 according to the first aspect, the reflector 2 is moved, but the moving table 5 corresponding to the XY stage in the prior art or the carbon heater in the prior art corresponds. Since the mass of the reflector 2 is small compared with the laser oscillator 1 and the optical system 3, position control which moves at high speed is easy. Then, the timing control means 8 adjusts the timing at which the laser oscillator 1 pulses the laser beam B1 and the timing at which the angle or position of the reflector 2 is changed by the reflector drive means 6. The position of the strip | belt-shaped irradiation area | region can be changed within the predetermined range of the major axis direction of the shape irradiation area | region.

From a 2nd viewpoint, this invention is the laser oscillator 1 which pulses the laser beam B1 according to the trigger G, the rotating polygon mirror 2 which reflects the said laser beam B1, and the said The direction in which the reflection beam B2 is shaken by the change in the incident angle θ of the laser beam B1 at the reflection surface 2b of the rotating polygon mirror 2 on which the laser beam B1 is incident is in the long axis direction. An optical system for shaping the reflective beam B2 onto the strip irradiation region 4 to irradiate the semiconductor substrate S, and the semiconductor substrate S being protected and held in a short axis direction of the strip irradiation region 4. A movable table 5 capable of moving in a direction, a rotation driving means 6 for rotating the rotating polygon mirror 2 at a constant speed, and a rotation for outputting rotation phase information Q of the rotating polygon mirror 2. Output timing of the trigger G based on the phase detection means 7 and the rotational phase information Q Is changed within a predetermined time range, and provides a laser irradiation device (100), characterized in that it comprises a timing control means (8) for a predetermined angle of incidence to the (θ) varies within the angle range.

In the laser irradiation apparatus 100 according to the second aspect, the rotating polygon mirror 2 should be rotated at a speed of 1 of the mirror moisture at a speed at which the angle of the mirror is to be changed and at a constant speed. It is easy to implement. And timing adjustment is also easy to change in order to change the timing which pulse-outputs the laser beam B1 with the laser oscillator 1 according to the rotational phase of the rotating polygon mirror 2. Therefore, the position of the strip-shaped irradiation area can be easily changed at high speed within a predetermined range in the major axis direction of the strip-shaped irradiation area.

According to the laser irradiation apparatus of the present invention, since the position control of moving the strip-shaped irradiation area at high speed in the major axis direction can be easily performed, the variation of the intensity of the laser beam in the major axis direction of the band-shaped irradiation area or the substrate to be processed is achieved. The change of irradiation of the longitudinal direction of the strip | belt-shaped irradiation area | region resulting from the minute unevenness | corrugation can be suitably controlled.

1 is a diagram for explaining the configuration of a laser irradiation apparatus according to a first embodiment.

2 is a timing chart showing the operation of the timing control circuit according to the first embodiment.

3 is a top view illustrating a position in the major axis direction of the strip-shaped irradiation area.

※ Explanation of code ※

One… Laser oscillator

2… Rotating polygon mirror

3a... Homogenizer

3b... Mirror

3c... lens

4… Strip Shape Irradiation Area

5... Mobile

6... motor

7... Encoder

8… Timing control circuit

100... Laser irradiation device

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated further in detail by embodiment shown to drawing. In addition, this invention is not limited by this.

(Example 1)

FIG. 1: is a structural explanatory drawing which shows the laser irradiation apparatus 100 which concerns on Example 1. FIG.

The laser irradiation apparatus 100 includes a laser oscillator 1 that pulses the laser beam B1 in response to the trigger G, a rotating polygon mirror 2 that reflects the laser beam B1, and a laser beam ( A strip-shaped irradiation area in which the reflection beam B2 is shaken in a long axis direction by a change in the incident angle θ of the laser beam B1 on the reflection surface 2b of the rotating polygon mirror 2 on which B2 is incident. The homogenizer 3a, the mirror 3b, the lens 3c, and the semiconductor substrate S for protecting the semiconductor substrate S by shaping the reflective beam B2 on the upper surface of the wafer 4 are band-shaped. Rotational stage 5 which can move in the short axis direction of the irradiation area 4, the motor 6 which rotates the rotating polygonal mirror 2 at a constant speed, and the rotational phase information Q of the rotating polygonal mirror 2 And timing for changing the output timing of the trigger (G) within a predetermined time range based on the encoder (7) for outputting the And a control circuit (8).

The rotation axis 2a of the rotation polygon mirror 2 is in the vertical direction, and the rotation polygon mirror 2 rotates in the horizontal plane. The laser beam B1 and the reflection beam B2 are in the horizontal direction. On the other hand, the semiconductor substrate S is laid horizontally. For this reason, the direction of the reflection beam B1 which equalized the intensity | strength in the long axis direction and the short axis direction with the homogenizer 3a is changed from the horizontal direction to the vertical direction by the mirror 3b. So that the light-converging lens for the short axis direction as bandalhyeong (3c) are irradiated to the semiconductor substrate (S).

2 is a timing chart illustrating the operation of the timing control circuit 8.

The timing control circuit 8 generates a 45 ° pulse Q 'indicating the timing at which the incident angle θ becomes 45 ° based on the rotational phase information Q. As shown in FIG.

The period τ of this 45 ° pulse Q 'is a value obtained by dividing one rotation time of the rotating polygon mirror 2 by the number of mirrors of the rotating polygon mirror 2.

In addition, the period τ corresponds to an average time interval at which the laser oscillator 1 pulses the laser beam B1. The time when the laser oscillator 1 pulses the laser beam B1, that is, the pulse width is shorter than the period τ.

When the number of positions where the band-shaped irradiation area 4 is to be moved in the major axis direction is "M + 1", the timing control circuit 8 randomly generates one of the integers m from 0 to M, The trigger G is output when "τ + (mM / 2) δ / (M / 2)" elapses from the 45 DEG pulse Q '.

When the angle at which the reflecting surface 2b is rotated between time δ is α, the incident angle θ becomes “45 °-(m-M / 2) α / (M / 2)”.

2 is an example of M = 8, and outputs the trigger G when "τ + (m-4) δ / 4" elapses from 45 ° pulse Q ', and the incident angle θ is "45 °- (m-4) α / 4 ".

3 is a top view illustrating the movement in the major axis direction of the strip-shaped irradiation area 4.

(a) to (i) correspond to m = 0 to m = 8 when M = 8.

The strip | belt-shaped irradiation area | region 4 moves to 9 positions in the long-axis direction irradiation range R at random.

When the length in the major axis direction of the strip-shaped irradiation area 4 is set to L, the change in the incident angle θ that moves only the band (R-L) / 2 to the strip-shaped irradiation area 4 corresponds to α.

According to the laser irradiation apparatus 100 of Example 1, since the rotating polygon mirror 2 needs only to be rotated one time by the mirror multiple times of period (tau), implementation is easy. Moreover, although the time interval which pulse-outputs the laser beam B1 with the laser oscillator 1 becomes shortest "(tau)-(delta)", since a movable part disappears, this also is easy to implement. Therefore, the position of the strip | belt-shaped irradiation area | region 4 can be moved at high speed in the predetermined range R of the major axis direction of the strip | belt-shaped irradiation area | region 4 at high speed.

(Example 2)

The trigger G may be randomly output within the time range from the elapse of "τ-δ" to the elapse of "τ + δ" after the 45 ° pulse Q '.

(Example 3)

Instead of the rotating polygon mirror 2, a mirror which reciprocates in the direction of the laser beam B1 may be used. In this case, the output timing of the trigger G is changed in accordance with the vibration phase.

(Example 4)

Instead of the rotating polygon mirror 2, a galvano-mirro oscillating in a predetermined angle range may be used. In this case, the output timing of the trigger G is changed in accordance with the rocking phase of the galvano mirror.

(Example 5)

Instead of the rotating polygon mirror 2, a galvano mirror may be used, the trigger G may be output at regular intervals, and the angle of the galvano mirror may be changed randomly in a predetermined angle range for each trigger G.

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

Claims (2)

A laser oscillator 1 that pulses a laser beam B1, a reflector 2 that reflects the laser beam B1, and a reflecting surface 2b of the reflector 2 on which the laser beam B1 is incident. The reflection beam B2 is shaped in the band-shaped irradiation area 4 having the long axis direction in which the reflection beam B2 moves due to a change in the angle θ or the position of the laser beam B1. An optical system 3 for irradiating the semiconductor substrate S, a movable table 5 which can protect the semiconductor substrate S and move in a short axis direction of the strip-shaped irradiation region 4, and the reflector 2 The laser beam B1 is pulsed by the laser oscillator 1 in order to change the position of the band-shaped irradiation area within a predetermined range of the long axis direction of the band-shaped irradiation area and the reflector driving means 6 for changing the angle or position of Timing to output and the angle of the reflector 2 to the reflector driving means 6 or The laser irradiation apparatus 1 characterized by including the timing control means 8 which adjusts the timing which changes a position. The laser oscillator 1 which pulses the laser beam B1 according to the trigger G, the rotating polygon mirror 2 which reflects the laser beam B1, and the rotation in which the laser beam B1 is incident. The reflection beam B2 is applied to the polygonal mirror 2 and the strip-shaped irradiation area 4 having the long axis direction in which the reflection beam B2 is shaken due to the change in the incident angle θ of the laser beam B1. An optical system (3) for shaping and irradiating the semiconductor substrate (S), the movable table (5) capable of moving in the short axis direction of the strip-shaped irradiation region (4) by protecting and holding the semiconductor substrate (S), and Rotation drive means 6 for rotating the rotation polygon mirror 2 at a constant speed, rotation phase detection means 7 for outputting rotation phase information Q of the rotation polygon mirror 2, and the rotation phase information Based on (Q), the output timing of the trigger G is changed within a predetermined time range, and the The laser irradiation apparatus (100) characterized by including timing control means (8) which changes the incident angle (θ) within a predetermined angle range.

Images