KR102109506B1 - A laser working system - Google Patents

Abstract

In order to achieve the above object, the present invention is a laser processing system for processing a workpiece using a laser beam, wherein the laser system is a laser processing unit that generates a laser beam at a predetermined output time for processing the workpiece. And, a laser irradiation time control unit for extracting a laser beam that satisfies a predetermined energy level by reaching a predetermined output value from the laser beam output from the laser processing unit is provided, and the laser irradiation time control unit There is provided a laser processing system characterized in that it is possible to reduce the damage to a workpiece by heat during laser processing by reducing the irradiation time at which the laser beam is irradiated on the object to be processed than the predetermined time.

Description

A laser working system

The present invention relates to a laser processing system for processing an object to be processed using a semiconductor laser in a semiconductor mask process, and more specifically, a semiconductor mask by heat during laser processing by controlling a laser irradiation time using an acoustic optical device (AOM). It relates to a laser processing system that can reduce the damage to the thin film surface, and improve the quality of the processed surface.

The processing apparatus using a laser irradiates a laser beam to a very local area in a non-contact manner with respect to the object to be processed, thereby removing a desired target or performing marking surface treatment without surrounding damage.

Such a laser processing apparatus is also used in a semiconductor mask process, and a laser beam is used to change the characteristics of a thin film by irradiating a laser beam to a thin film material during the manufacturing process of the semiconductor mask.

At this time, the change of the semiconductor mask thin film material appears differently according to the output and irradiation time of the laser beam, and the longer the irradiation time of the laser beam, the more damage is caused to the thin film. Processing quality is improved.

That is, when processing using a semiconductor laser, based on continuous oscillation, the output can be adjusted by the input control signal, and the control of the laser irradiation time turns ON the control signal input to a device that controls the irradiation time of the semiconductor laser. It is possible by / OFF.

When processing using a semiconductor laser by an ON / OFF operation of the semiconductor laser by the control signal processing as described above, when a control signal is applied to the laser generation unit that emits the semiconductor laser (ON), until the output value set in the laser is reached. It took a delay time of several tens of microseconds, and it was difficult to perform the process using the energy of the maximum efficiency of the laser.

In addition, due to the delay time (delay), the laser is not irradiated to the object to be processed or only a very low-power laser is oscillated to obtain sufficient energy required for the process, which may adversely affect the laser processing quality.

Therefore, although many electrical circuits have been developed to shorten the delay time of several tens of microseconds, it is difficult to shorten the time of tens of microseconds.

Republic of Korea Registered Patent Publication No. 10-1189537 Republic of Korea Registered Patent Publication No. 10-1233422 Republic of Korea Patent Publication No. 10-2010-0044774

The present invention is to solve the above-mentioned problems, and the object of the present invention is to provide a semiconductor laser processing system capable of shortening the irradiation time of the semiconductor laser by using energy of the maximum efficiency of the semiconductor laser when processing.

However, the object of the present invention is not limited to the above-mentioned object, another object not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a semiconductor laser processing system for processing an object to be processed by irradiating a semiconductor laser of the present invention takes time before the semiconductor laser reaches a predetermined output value before irradiating a beam to the object. There is provided a semiconductor laser processing system characterized in that by irradiating the object to be processed after control, the irradiation time of the laser beam to the object can be reduced to reduce damage to the object due to heat during laser processing.

In addition, the semiconductor laser system includes a laser supply unit for generating the semiconductor laser, a laser processing unit for irradiating the semiconductor laser generated from the laser supply to the object, and the time until the semiconductor laser reaches a predetermined output value. A control unit for controlling the operation of the laser supply unit and the laser processing unit is provided to reduce the.

At this time, the laser supply unit is provided with a semiconductor laser output unit for outputting the semiconductor laser, and a laser controller for generating a control signal for controlling ON / OFF of the semiconductor laser output unit.

In addition, the laser processing unit receives a semiconductor laser output from the semiconductor laser output unit and diffracts it to have different diffraction angles, and an optical modulation controller that generates a control signal for controlling ON / OFF of the optical modulation unit. It is made including.

In addition, the optical modulation unit is characterized in that the acoustic optical device (AOM; Acoustic Optic Modulator).

On the other hand, the control unit is turned on so that the ON operation of the light modulation controller is operated at regular intervals after the ON operation of the laser controller, and the OFF operation of the laser controller is operated at regular intervals after the OFF operation of the light modulation controller. Synchronize the controller and the light modulation controller.

In addition, the optical modulator is diffracted by a primary diffraction beam having a first diffraction angle to emit the semiconductor laser output from the semiconductor laser output unit during operation, and when the operation is stopped, the semiconductor laser output from the semiconductor laser output unit is 0. It is transmitted through a diffraction beam.

In addition, the laser processing unit comprises an optical unit that receives the first diffraction beam diffracted from the light modulation unit and is emitted to be irradiated to a target position of the object to be processed.

In addition, the 0th-order diffraction beam is emitted in the same direction as the semiconductor laser output from the semiconductor laser output unit enters the light modulation unit, and the primary diffraction beam is a semiconductor laser output from the semiconductor laser output unit. Is emitted in the same direction as the direction incident on the light modulator and is deflected by a predetermined angle θ1 based on the 0th-order diffraction beam.

In addition, the semiconductor laser output from the semiconductor laser output unit is output by an ON signal of the laser controller, a rising period in which an output value reaches a preset output value from 0, and a preset interval by an OFF signal of the laser controller A falling period from output value to output value 0 is formed.

Then, when the semiconductor laser reaches a predetermined output value Ta, and when the OFF signal of the laser controller is output as Tb, the control unit operates the light modulator in a section between the time Ta and the time Tb. .

In addition, in the laser system, the semiconductor laser output unit is operated by an ON signal of the laser controller, and the semiconductor module output from the semiconductor laser output unit in an operation stop (OFF) state in the rising section. Is transmitted through the zero-order diffraction beam.

Then, after the rising period, the optical modulation unit is operated by the ON signal of the optical modulation controller to diffract the semiconductor laser output from the semiconductor laser output unit into the first diffraction beam and then laser-process the object to be processed. , The optical modulation unit is turned off by the OFF signal of the optical modulation controller and transmits the semiconductor laser output from the semiconductor laser output unit to the zero-order diffraction beam, and the semiconductor laser output unit is stopped by the OFF signal of the laser controller. .

In addition, the first diffraction beam diffracted from the light modulation unit is diffracted by the ON signal of the light modulation controller to a rising period in which an output value reaches a preset output value from 0, and an OFF signal of the light modulation controller. By this, a falling section reaching the output value 0 from a preset output value is formed.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings.

Prior to this, the terms or words used in the specification and claims should not be interpreted in a conventional and lexical sense, and the inventor can properly define the concept of terms in order to best describe his or her invention. Based on the principle of being present, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

As described above, according to the present invention, when using a laser beam, while using the energy of the maximum efficiency of the laser beam while shortening the irradiation time of the laser beam than conventional, reducing the time to be exposed to heat, thermal damage to the surface of the semiconductor mask It has the effect of reducing and improving the quality of the machined surface.

1 is a view for explaining the output state of a typical laser beam,
Figure 2 is a view for schematically showing the output state of the laser beam according to the operating state of the laser system according to an embodiment of the present invention,
Figure 3 is a block diagram schematically showing the operating state of the laser system according to an embodiment of the present invention,
Figure 4 is a block diagram schematically showing the operating state of the laser system during processing according to an embodiment of the present invention,
5 is a block diagram schematically showing an operating state of a laser system during non-processing according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience.

In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or practice. Therefore, definitions of these terms should be made based on the contents throughout the present specification.

In addition, the following embodiments are not intended to limit the scope of the present invention, but are merely illustrative of the components presented in the claims of the present invention, and are included in the technical idea throughout the specification of the present invention and constitute the claims. Embodiments that include a substitutable component as an equivalent in the elements can be included in the scope of the present invention.

Attached Figure 1 is a view for explaining the output state of a general laser beam, Figure 2 is a view for schematically showing the output state of the laser beam according to the operating state of the laser system according to an embodiment of the present invention, 3 is a block diagram schematically showing an operating state of the laser system according to an exemplary embodiment of the present invention, and FIG. 4 is a block diagram schematically showing an operating state of the laser system during processing according to an exemplary embodiment of the present invention. 5 is a block diagram schematically showing an operating state of a laser system during non-processing according to a preferred embodiment of the present invention.

1, the present invention relates to a semiconductor laser processing system for processing a workpiece using a semiconductor laser in a semiconductor mask process, the laser processing system capable of controlling the laser irradiation time irradiated to the workpiece It is about.

Accordingly, the laser system according to the present invention reduces the irradiation time of the laser beam to the object to be processed by controlling the time until the semiconductor laser reaches a preset output value before irradiating the beam to the object. It is characterized in that it is possible to reduce damage to a workpiece due to heat during laser processing.

Accordingly, the semiconductor laser system includes a laser supply unit 10 for generating the semiconductor laser, a laser processing unit 20 for irradiating the semiconductor laser generated from the laser supply unit 10 to the object to be processed, and the semiconductor laser. A control unit 30 is provided to control the operation of the laser supply unit 10 and the laser processing unit 20 to reduce the time until reaching the set output value.

Also, the laser supply unit 10 includes a semiconductor laser output unit 11 through which the semiconductor laser is output, and a laser controller 12 that generates a control signal for controlling ON / OFF of the semiconductor laser output unit 11. Including.

In addition, the laser processing unit 20 receives the semiconductor laser output from the semiconductor laser output unit and diffracts them to have different diffraction angles, and controls to control ON / OFF of the optical modulation unit. It comprises a light modulation controller 22 for generating a signal.

In addition, the optical modulation unit 21 is preferably provided with an acoustic optical device (AOM; Acoustic Optic Modulator).

The optical modulator 21 diffracts and outputs the semiconductor laser output from the semiconductor laser output unit 11 as a primary diffraction beam having a first diffraction angle during operation, and when the operation is stopped, the semiconductor laser output unit 11 ) Transmits the semiconductor laser output from the 0th-order diffraction beam.

In addition, the 0th-order diffraction beam is emitted in the same direction as the semiconductor laser output from the semiconductor laser output unit 11 enters the light modulation unit 21, and the primary diffraction beam is the semiconductor laser As the semiconductor laser output from the output unit 11 is emitted in the same direction as the direction in which the light modulator 21 is incident, it is deflected by a predetermined angle θ1 based on the 0th-order diffraction beam.

Accordingly, the acoustic optical device (AOM) may be composed of an electrode attached to an acoustic optical medium, and an electro-acoustic modulator that generates acoustic acoustic waves depending on an electrical signal applied from a driving circuit through the electrode.

In addition, when a signal by a laser beam from the driving circuit is applied to the electro-acoustic modulator, the electro-acoustic modulator generates an acoustic wave surface in the acoustic optical medium, and the laser beam of a predetermined wavelength incident on the incident surface of the acoustic optical medium is acoustic Bragg is reflected from the wavefront and is emitted as 1st order diffracted light, and a part of the incident laser beam is not diffracted at the acoustic wavefront but is emitted as 0th order diffracted light.

In addition, the diffraction rate of the Acoustic Optic Modulator (AOM) is formed from 85% to 95%.

The laser processing unit 20 may further include an optical unit 23 that receives the primary diffraction beam diffracted from the light modulation unit 21 and is radiated to a target position of the object to be processed.

Also, the laser processing unit 20 may further include a shutter 24 that receives and blocks the 0th-order diffraction beam transmitted from the light modulation unit 21 and emitted.

On the other hand, the control unit 30 is the ON operation of the optical modulation controller 21 is operated at regular intervals after the ON operation of the laser controller 11, the OFF operation of the laser controller 11 is the optical modulation controller After the OFF operation of (22), the laser controller 11 and the light modulation controller 22 are synchronized to operate at regular intervals.

In addition, the semiconductor laser output from the semiconductor laser output unit 11 is output by the ON signal of the laser controller 12, the rising value reaches a preset output value from 0, and a rising section, the laser controller ( By the OFF signal of 12), a falling section reaching the output value 0 from a preset output value is formed.

And when the time when the semiconductor laser reaches a predetermined output value is Ta and the time when the OFF signal of the laser controller 12 is output is Tb, the control unit 30 is in a section between the time point Ta and the time point Tb. It characterized in that to operate the light modulator 21.

In addition, the first diffraction beam diffracted from the light modulation unit 21 is diffracted by the ON signal of the light modulation controller 22, and a rising section in which an output value reaches a preset output value from 0, and the light A falling section reaching the output value 0 from a preset output value is formed by the OFF signal of the modulation controller.

In addition, when the time point at which the primary diffraction beam reaches a predetermined output value is Tc and the time point at which the OFF signal of the optical modulation controller is output is Td, the rising period and falling of the primary diffraction beam The section may be formed from 1/10 times to 1/1000 times the rising and falling section of the semiconductor laser output from the semiconductor laser output unit 11, but this is the output value of the semiconductor laser, the optical modulation controller It is natural that the section can be formed from 1/10 times to 1 / thousands of times because it can be changed depending on the design of.

Accordingly, in the laser system, the semiconductor laser output unit 11 is operated by the ON signal of the laser controller 12, and in the rising section, the light modulation unit 21 is in an OFF state. The semiconductor laser output from the semiconductor laser output unit 11 is transmitted through the zero-order diffraction beam.

In addition, after the rising period, the light modulation unit 21 is operated by the ON signal of the light modulation controller 22 to convert the semiconductor laser output from the semiconductor laser output unit 11 into the first diffraction beam. After diffracting and laser-processing the object to be processed, the optical modulation unit 21 is stopped by the OFF signal of the optical modulation controller 22, so that the semiconductor laser output from the semiconductor laser output unit 11 is zero-order diffraction. Through the beam, the semiconductor laser output unit 11 is stopped by the OFF signal of the laser controller 12.

Accordingly, the rising and falling sections of the laser output from the semiconductor laser output unit 11 take tens of microseconds (ㅅ s), whereas the first diffraction beam diffracted by the light modulation unit 21 The rising and falling sections of can reduce the time to heat exposure by reducing the time until reaching a predetermined output value in several microseconds (ㅅ s).

For example, if 50W power is scanned for 200us using a laser output from the semiconductor laser output unit 11, the first diffraction beam diffracted by the light modulation unit 21 has a time to reach a predetermined output value. Even if only 150us of 50W is injected, the same amount of energy is injected, so that the heat exposure time is reduced, thereby preventing thermal damage at the interface where heat is transferred.

In addition, since the amount of heat transferred in the direction in which the laser beam is not scanned is also reduced in the boundary where the laser beam is scanned, edge sharpness at the interface is steeply formed, so that a sharper surface can be obtained.

In other words, when the boundary surface of the object to be processed, which has a relatively longer heat transfer time, is viewed through TEM, the slope becomes larger, and the smaller the heat transfer time, the smaller the slope of the slope, so the boundary surface is clear and the quality of the processed surface is improved. do.

Therefore, by irradiating the object to be processed by using the laser beam diffracted from the light modulator 21, a predetermined output value can be quickly reached and laser processing can be performed using the energy of the maximum efficiency for a set time. It has the effect of reducing damage and improving the quality of the machined surface.

Although the present invention has been described in detail through specific examples, the present invention is specifically for describing the present invention, and the present invention is not limited to this, and by those skilled in the art within the technical spirit of the present invention. It is clear that modification and improvement are possible.

All simple modifications or changes of the present invention belong to the scope of the present invention, and the specific protection scope of the present invention will be clarified by the appended claims.

10: laser supply unit 11: laser output unit
12: laser controller 20: laser processing unit
21: light modulation unit 22: light modulation controller
30: control unit

Claims (9)

In the semiconductor laser processing system for processing the object to be processed by irradiating a semiconductor laser,
The semiconductor laser system,
By controlling the time until the semiconductor laser reaches a predetermined output value before irradiating the beam to the object to be processed, irradiating the object to be processed to reduce the irradiation time of the laser beam to the object to be processed by heat during laser processing To reduce damage to the object
The semiconductor laser system,
A laser supply unit for generating the semiconductor laser,
A laser processing unit for irradiating a semiconductor laser generated from the laser supply to the object to be processed;
A control unit is provided to control the operation of the laser supply unit and the laser processing unit to reduce the time until the semiconductor laser reaches a predetermined output value.
The laser supply unit,
A semiconductor laser output unit for outputting the semiconductor laser,
A laser controller that generates a control signal for controlling ON / OFF of the semiconductor laser output unit is included.
The laser processing unit,
And a light modulator for receiving the semiconductor laser output from the semiconductor laser output unit to diffract to have a different diffraction angle,
An optical modulation controller for generating a control signal for controlling the ON / OFF of the optical modulation unit is included,
The control unit,
The ON operation of the light modulation controller is operated at regular intervals after the ON operation of the laser controller,
The OFF operation of the laser controller synchronizes the laser controller and the optical modulation controller so that the optical modulation controller operates at regular intervals after the OFF operation.
The light modulator,
In operation, the semiconductor laser output from the semiconductor laser output unit is diffracted and radiated into a first diffraction beam having a first diffraction angle,
When the operation is stopped, the semiconductor laser output from the semiconductor laser output unit is transmitted through a zero-order diffraction beam
The semiconductor laser output from the semiconductor laser output unit,
There is a rising section in which the output value reaches the preset output value from 0 by the ON signal of the laser controller, and a falling interval in which the output value reaches the output value 0 in the preset output value by the OFF signal of the laser controller. Is formed,
When the time when the semiconductor laser reaches a predetermined output value is Ta, and when the OFF signal of the laser controller is output is Tb,
The control unit operates the light modulator in a section between the time point Ta and the time point Tb,
In the laser system, the semiconductor laser output unit 11 is operated by an ON signal from the laser controller 12, and the optical modulator 21 is in an OFF state in the rising section. The semiconductor laser output from the laser output unit 11 is transmitted through the zero-order diffraction beam,
After the rising period, the light modulation unit 21 is operated by the ON signal of the light modulation controller 22 to diffract the semiconductor laser output from the semiconductor laser output unit 11 into the first diffraction beam. After laser processing the object to be processed, the optical modulation unit 21 is stopped by the OFF signal of the optical modulation controller 22 and the semiconductor laser output from the semiconductor laser output unit 11 is zero-order diffraction beam. And the semiconductor laser output unit 11 is stopped by the OFF signal of the laser controller 12.
When the point at which the first diffraction beam reaches a predetermined output value is Tc and the time at which the OFF signal of the light modulation controller is output is Td, the rising and falling intervals of the first diffraction beam are Is a semiconductor laser processing system, characterized in that formed from 1/10 times to 1/1000 times the rising and falling sections of the semiconductor laser output from the semiconductor laser output section 11.
delete delete delete According to claim 1,
The optical modulator is an acoustic optical device (AOM; Acoustic Optic Modulator) semiconductor laser processing system, characterized in that.
delete delete According to claim 1, The laser processing unit,
A semiconductor laser processing system comprising an optical unit that receives a first diffraction beam diffracted from the light modulation unit and is emitted to be irradiated to a target position of the object to be processed.

delete

Images