JP2000200760A - Laser annealing processing method and laser annealing processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the energy density with which a substrate is irradiated to be constant by detecting substrate irradiating laser beams by means of a sensor, and controlling an attenuator installed in the transmission path of the laser beams so that the detected power value becomes close to a target power value. SOLUTION: A sensor 10 is arranged just before a slit board 6 and the power values of laser beams in the spatial ranges of (W1-W2)/2, which are formed on both sides of a slit 5, are detected. A control part 11 constituted of a micro computer as a necessary part compares a target power value with which a substrate 3 is to be irradiated with the detected power value of the sensor 10. The inclination angles of movable filters 7a and 7b constituting an attenuator 14 are repetitively and automatically controlled during an operation so as to bring the detected power value close to the target power value. Since the it is possible to automatically control the irradiation power value to the substrate 3 occasionally to be equal to the target power value with such a constitution, the density of energy with which the substrate 3 is irradiated can be made constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laser annealing method for annealing an object to be irradiated by laser irradiation.

[0002]

2. Description of the Related Art In order to carry out a laser annealing process, a laser annealing device shown in FIG. 3 is used.

This device includes a laser oscillation device 1 for generating and emitting a laser beam, an optical system 2 including a plurality of laser optical lenses installed in a path of the laser beam emitted from the laser oscillation device 1, and A mirror 4 that bends the optical path to the side of the substrate 3 that is subjected to the laser light annealing process, and a slit plate 6 that has a slit 5 that defines the width of the laser light to be irradiated
And movable filters 7 a and 7 b for an attenuator interposed in a laser light transmission path, and a halogen injection device 8.

The tilt angles of the movable filters 7a and 7b are initially set at the start of operation so that the laser power value on the processing surface of the substrate 3 becomes the target power value, and the tilt angles during operation are not changed. It is.

As shown in FIG. 3 for one substrate 3,
The laser beam is irradiated with a predetermined number of laser beams while the laser beam and the substrate 3 are relatively moved, so that the annealing process of one substrate 3 is completed, the substrate 3 is replaced, and the annealing process is repeated.

[0006] The gas contained in the laser tube 9 of the laser oscillation device 1 is deteriorated and the power is reduced.
For that purpose, the applied voltage of the laser is increased in order to keep the power value of the emitted laser constant, but when the applied voltage becomes, for example, 20 kV or more, the halogen injection device 8 automatically executes the halogen injection operation. It is configured.

Specifically, as shown in FIG. 4, cylinders of Xe, Ne, HCl, and He are connected to the laser tube 9, and 2 kg is stored in the laser tube 9 during operation.
Xe, Ne, and HCl are sealed so as to be about / cm ² .

During the halogen injection operation, the valve of the HCl cylinder is temporarily opened, and the internal pressure of HCl of about 4 kg / cm ² to 5 kg / cm ^2.
HCl gas is injected into the laser tube 9 from the cylinder. He is used for cleaning the inside of the laser tube 9.

[0009]

However, in the conventional laser annealing method as described above, since the transmittance of the optical lens of the optical system 2 decreases with time, the energy applied to the substrate 3 is reduced. There is a problem that the density decreases over time.

Further, even when the halogen injection operation is automatically performed, there is a problem that when the halogen injection is performed during the film formation of the substrate, the fluctuation of the power becomes large and a failure occurs.

The present invention has been made in order to solve the above problems.
It is an object of the present invention to provide a laser annealing method capable of keeping the energy density applied to a substrate constant even when the transmittance of an optical lens is lowered or when gas deteriorates.

[0012]

According to the laser annealing method of the present invention, a laser beam irradiated on a substrate is detected by a sensor, and a laser power is transmitted through a laser light transmission path so that the detected power value approaches a target power value. Controlling an attenuator interposed in the horn.

According to the structure of the present invention, the energy density applied to the substrate can be kept constant even when the transmittance of the optical lens decreases or when the gas deteriorates.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a laser annealing method according to a first aspect of the present invention, when a substrate is irradiated with laser light emitted from a laser oscillating device and then annealed, the laser light applied to the substrate is irradiated. By controlling the incident angle of the laser light of the attenuator interposed in the laser light transmission path and changing the transmittance of the attenuator so that the detected power value approaches the target power value by detecting with the sensor, the transmittance of the attenuator is changed to the substrate. It is characterized in that the irradiated energy density is constant.

In the laser annealing method according to the second aspect of the present invention, when a substrate is irradiated with a laser beam emitted from a laser oscillation device to perform an annealing process, a voltage applied to a laser tube is checked and the specified value is obtained. It is characterized in that a halogen gas is refilled into the laser tube upon detecting the above.

According to a third aspect of the present invention, in the first aspect, the voltage applied to the laser tube is checked before irradiating the substrate, and it is detected that the applied voltage exceeds a specified value. And refilling the laser tube with halogen gas.

According to a fourth aspect of the present invention, there is provided a laser annealing method according to the first aspect, wherein the voltage applied to the laser tube is checked during the irradiation of the substrate, and when it is detected that the voltage exceeds a specified value. And replenishing the laser tube with a halogen gas before the annealing of the substrate being completed is completed and before the annealing of the next substrate is started.

According to a fifth aspect of the present invention, there is provided a laser annealing apparatus for irradiating a substrate with laser light emitted from a laser oscillating apparatus and performing an annealing process. An attenuator for controlling the incident angle to change the transmittance, a sensor for detecting a laser beam applied to the substrate, and a laser beam incident on the attenuator such that a detected power value of the sensor approaches a target power value. Controls the angle,
A control unit is provided for checking a voltage applied to a laser tube of the laser oscillation device, and detecting that the voltage exceeds a specified value, and replenishing the laser tube with a halogen gas.

According to a sixth aspect of the present invention, in the laser annealing apparatus according to the fifth aspect, a warning is provided by detecting a state in which the deviation between the target power value and the detected power value detected by the sensor has exceeded a specified value. Is provided.

Hereinafter, the laser annealing method of the present invention will be described based on specific embodiments. It is to be noted that components having the same functions as those in FIG.

FIG. 1 shows a laser annealing apparatus for realizing the laser annealing method of the present invention.

This embodiment differs from FIG. 3 showing a conventional example only in that a sensor 10, a control unit 11, and an alarm 12 are added.

Here, assuming that the irradiation width of the laser light 13 irradiated to the slit plate 6 via the mirror 4 is W1 and the irradiation width of the laser light passing through the slit 5 of the slit plate 6 is W2, the sensor 10 , Disposed just before the slit plate 6 and formed on both sides of the slit 5 in FIG.
-W2) / 2 is arranged to detect the power value of the laser beam in the range.

The control unit 11 is mainly composed of a microcomputer and repeatedly executes the following first to third control routines.

The first control routine is to compare a target power value to be applied to the substrate 3 with a detected power value of the sensor 10, and to form a movable filter which constitutes the attenuator 14 so that the detected power value approaches the target power value. It is configured to repeatedly and automatically control the inclination angles of 7a and 7b during operation.

The second control routine is configured to detect that the deviation between the target power value and the detected power value of the sensor 10 exceeds a specified value, and instruct the alarm device 12 to generate an alarm sound. I have.

The third control routine is to detect that the applied voltage of the laser tube 9 has risen to a specified value or more even if the applied voltage has not reached the number of times of the automatic halogen injection. The apparatus 8 is configured to instruct the apparatus 8 to perform forced halogen injection.

More specifically, the first control routine is repeatedly executed to automatically control the occasional irradiation power value on the substrate 3 to the target power value. Even when the deterioration occurs, the energy density applied to the substrate 3 can be kept constant, and a stable annealing process can be realized.

The applied voltage value for executing the forced injection in the third control routine is set as shown in FIG. As can be seen from FIG. 2, as the number of shots increases, the gas deteriorates and the applied voltage gradually increases.

Assuming that the applied voltage serving as a criterion for automatic injection performed conventionally is 20 kV, the applied voltage value for executing the forced injection in the third control routine is about 19 kV lower than 20 kV. If it is determined that the applied voltage of the laser tube 9 has increased to about 19 kV or more during operation, the annealing process is continued for the substrate 3 in the middle of the annealing process, and the annealing process for the next substrate 3 is started. Forced injection is performed prior to preventing a mistake in irradiation power control due to gas deterioration. Whether the annealing process is in progress can be determined by checking the operation information A.

Further, such a state that the irradiation power is reduced in spite of the control operation is detected by executing the second control routine, and an alarm sound is generated when this abnormal situation occurs. The operator can be notified promptly.

In the above embodiment, the necessity of forced injection was determined during operation. However, the necessity of forced injection was determined each time the annealing process of each substrate 3 was started, or the necessity of forced injection was determined. Each time the necessity of forced injection is determined, the necessity of forced injection may be determined during operation.

[0033]

As described above, according to the laser annealing method of the present invention, even when the transmittance of the laser lens in the path of the laser beam changes, a laser with a more accurate energy density is irradiated onto the substrate. be able to.

Further, the laser annealing apparatus of the present invention can irradiate the substrate with a laser having a more accurate energy density even when the energy emitted from the laser oscillator changes.

Further, it is possible to prevent the fluctuation of the laser energy occurring at the time of halogen injection from occurring at the time of irradiating the substrate, and to irradiate the laser energy in a stable state.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a laser annealing apparatus that realizes a laser annealing method of the present invention.

FIG. 2 is an explanatory diagram of a forced injection according to the embodiment;

FIG. 3 is a configuration diagram of a conventional laser annealing apparatus.

FIG. 4 is an explanatory view of a halogen injection of the conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser oscillation device 2 optical system 3 substrate subjected to annealing process 4 mirror 5 slit 6 slit plate 7 a, 7 b movable filter for attenuator 8 halogen injection device 10 sensor 11 control unit 12 alarm

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (reference) H01S 3/00 H01S 3/00 G // B23K 101: 38 F term (reference) 4E068 AH00 CA01 CA02 CA17 CA18 CB02 CC01 CD10 CE01 CK01 DA11 5F052 AA02 BB07 CA07 5F072 AA06 HH02 JJ05 JJ11 JJ20 KK30 YY20

Claims (6)

[Claims] A laser beam irradiated on a substrate is detected by a sensor, and an incident angle of the laser beam of an attenuator interposed in a transmission path of the laser beam is adjusted so that the detected power value approaches a target power value. A laser annealing method for controlling the transmittance of the attenuator to thereby keep the energy density applied to the substrate constant. 2. A laser annealing method for checking a voltage applied to a laser tube, detecting that the applied voltage has exceeded a specified value, and refilling the laser tube with a halogen gas. 3. The laser according to claim 1, wherein a voltage applied to the laser tube is checked before irradiating the substrate, and when the voltage exceeds a specified value, a halogen gas is supplied to the laser tube. Annealing treatment method. 4. When the voltage applied to the laser tube is checked during the irradiation of the substrate, and it is detected that the voltage exceeds a specified value, the annealing process of the substrate in progress is completed and the annealing process of the next substrate is completed. 2. The laser annealing method according to claim 1, wherein a halogen gas is replenished to the laser tube before starting. 5. A laser annealing apparatus for irradiating a substrate with laser light emitted from a laser oscillation apparatus and annealing the substrate, wherein the attenuator is interposed in a transmission path of the laser light to control an incident angle to change transmittance. A sensor for detecting a laser beam applied to the substrate; and controlling an incident angle of the laser beam of the attenuator so that a detected power value of the sensor approaches a target power value, and a laser tube of the laser oscillation device. A laser annealing processing apparatus provided with a control unit for checking a voltage applied to the laser tube and detecting that the applied voltage is equal to or more than a specified value, and replenishing the laser tube with a halogen gas. 6. The laser annealing apparatus according to claim 5, further comprising alarm means for detecting a state in which a deviation between the target power value and the detected power value detected by the sensor is equal to or greater than a specified value and generating an alarm.