KR102531651B1 - Laser crystalling apparatus - Google Patents

Abstract

A laser crystallization apparatus according to an embodiment of the present invention includes a laser generator for generating an incident laser beam, an optical system for processing the incident laser beam to generate an output laser beam, a monitoring unit for monitoring the output laser beam, and the output laser beam. It includes a process chamber in which the thin film is crystallized by irradiation, and an inspection unit inspecting the thin film in the process chamber.

Description

Laser crystallization device {LASER CRYSTALLING APPARATUS}

The present invention relates to a laser crystallization device.

In general, methods for crystallizing an amorphous silicon layer into a poly-crystal silicon layer include solid phase crystallization (SPC), metal induced crystallization (MIC), There are Metal Induced Lateral Crystallization (MILC) and Excimer Laser Annealing (ELA).

In particular, in the manufacturing process of an organic light emitting diode display (OLED) or a liquid crystal display (LCD), an excimer laser heat treatment method (ELA) for crystallizing amorphous silicon into polycrystalline silicon using a laser beam Use

A laser crystallization device used in the excimer laser annealing (ELA) includes a laser generator for generating a source laser beam. Here, the source laser beam is the first unprocessed laser beam. Accordingly, the laser crystallization apparatus includes an optical system for processing a source laser beam into a laser beam having a uniform energy distribution.

On the other hand, laser crystallization proceeds by scanning while overlapping laser beams. At this time, a defect may occur due to an energy difference between a plurality of shots.

A technical problem to be achieved by the present invention is to provide a laser crystallization apparatus capable of minimizing crystallization defects.

A laser crystallization apparatus according to an embodiment of the present invention includes a laser generator for generating an incident laser beam, an optical system for processing the incident laser beam to generate an output laser beam, a monitoring unit for monitoring the output laser beam, and the output laser beam. It includes a process chamber in which the thin film is crystallized by irradiation, and an inspection unit inspecting the thin film in the process chamber.

The monitoring unit may check the shortening of the emitted laser beam and quantify the steepness.

The inspection unit may inspect the thin film and digitize a short axis peak of the emission laser beam.

The laser crystallization apparatus according to an embodiment of the present invention may further include a control unit that collects the digitized stiffness data and the digitized data of the shortened peak of the emitted laser beam.

The controller may feed back the collected data to the optical system.

The optical system may include a plurality of lenses and a plurality of modulators.

The optical system may move the plurality of lenses and the plurality of modulators according to the fed back data.

The optical system may further include a motor for moving the plurality of lenses and the plurality of modulators.

The optical system may include a reflection mirror that reflects a portion of the emitted laser beam to the monitoring unit.

When the thin film is crystallized by the laser crystallization device according to the embodiment of the present invention, it is possible to improve streak defects.

1 is a diagram schematically illustrating a laser crystallization apparatus according to an embodiment of the present invention.
2 is a diagram schematically illustrating a short-axis profile of an emitting laser beam.
FIG. 3(a) shows an image of a thin film before stiffness is corrected, and FIG. 3(b) shows an image of a thin film after stiffness is corrected.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, the present invention is not necessarily limited to the shown bar.

In the drawings, the thickness is shown enlarged to clearly express the various layers and regions. And in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated. When a part such as a layer, film, region, plate, etc. is said to be "on" or "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between.

In addition, throughout the specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated. In addition, throughout the specification, "on" means to be located above or below the target part, and does not necessarily mean to be located on the upper side relative to the direction of gravity.

In addition, throughout the specification, when it is referred to as "planar image", it means when the target part is viewed from above, and when it is referred to as "cross-sectional image", it means when a cross section of the target part cut vertically is viewed from the side.

Then, a laser crystallization apparatus according to an embodiment of the present invention will be described with reference to FIG. 1 .

1 is a diagram schematically illustrating a laser crystallization apparatus according to an embodiment of the present invention.

Referring to FIG. 1 , the laser crystallization apparatus 1000 according to the present embodiment includes a laser generator 100 that generates a laser incident laser beam L, and an output laser beam L1 by processing the incident laser beam L. and a process chamber 300 in which a process of crystallizing the thin film T formed on the substrate G by irradiating the optical system 200 and the emitting laser beam L1 is performed.

In addition, the laser crystallization apparatus 1000 according to the present embodiment includes a monitoring unit 400 for monitoring the output laser beam L1 emitted from the optical system 200, and a thin film crystallized in the process chamber 300 ( It includes an inspection unit 500 and a monitoring unit 400 that inspect T) and a control unit 600 that feeds back digitized data from the inspection unit 500 to an optical system.

The laser generator 100 is a device that generates an incident laser beam L, and may include a laser generator. The incident laser beam L may be an excimer laser beam that induces a phase change of the thin film T.

The optical system 200 changes the energy distribution of an incident laser beam (L) having an asymmetrical energy distribution, and changes it into an outgoing laser beam (L1) having a uniform energy distribution.

The optical system 200 includes a plurality of lenses and a plurality of modulators. A plurality of lenses and a plurality of modulators invert the incident laser beam L in the major axis direction and the minor axis direction to change it into an outgoing laser beam L1.

Crystallization of the thin film T formed on the substrate G is performed in the process chamber 300 . The emitting laser beam L1 is irradiated to the thin film T to achieve crystallization of the thin film T.

A stage S on which a substrate G on which a thin film T is formed is placed is positioned in the process chamber 300 . Here, the thin film T may be an amorphous silicon layer, which is low pressure chemical vapor deposition (LPCVD), atmospheric pressure chemical vapor deposition (APCVD), plasma enhanced chemical vapor deposition (PECVD), sputtering (sputtering), vacuum It may be formed by a method such as vacuum evaporation.

The monitoring unit 400 monitors the output laser beam L1 emitted from the optical system 200 .

The emitted laser beam L1 emitted from the optical system 200 is irradiated into the process chamber 300, and the monitoring unit 400 receives and monitors a portion of the emitted laser beam L1 emitted from the optical system 200. At this time, the optical system 200 may include a reflection mirror that reflects a portion of the emitted laser beam L1 to the monitoring unit 400 .

The monitoring unit 400 receives and monitors a portion of the emitted laser beam L1 emitted from the optical system 200 to quantify the steepness of the emitted laser beam L1. The stiffness can be quantified by checking the shortening of the emitting laser beam L1.

The inspection unit 500 inspects the thin film T undergoing crystallization in the process chamber 300 with a microscope.

When the thin film T is crystallized, the emission laser beam L1 is overlapped and scanned, and at this time, the difference in intensity of energy is caused by the profile of the emission laser beam L1. Occurs. When the thin film T is crystallized due to this difference in energy intensity, streaks occur. The stripe is caused by a difference in energy of the short-axis of the emitting laser beam L1 at intervals of scan pitches of the emitting laser beam L1.

In the inspection unit 500, the thin film T undergoing crystallization is inspected under a microscope to quantify the short-axis peak of the emission laser beam L1 according to the streak pattern.

The control unit 600 collects the stiffness data of the emitted laser beam L1 digitized by the monitoring unit 400 and the short-axis peak data of the emitted laser beam L1 digitized by the inspection unit 500, and transmits the data to the optical system 200. give feedback

In order to improve the unevenness of lines according to the interval of the scan pitch of the emitting laser beam L1, it is necessary to increase the stiffness. In addition, when the short-axis peak of the emitted laser beam L1 increases, it is necessary to correct the stiffness. Accordingly, the control unit 600 feeds back the collected data to the optical system 200, and the optical system 200 moves the positions of the plurality of lenses and the plurality of modulators according to the feedback data to determine the stiffness of the emitted laser beam L1. can be corrected. In particular, among a plurality of lenses and a plurality of modulators, the stiffness of the emitted laser beam L1 can be corrected by adjusting the lens and modulator involved in the shortening of the emitted laser beam L1. At this time, the lens or modulator may be automatically moved by mounting a motor on the lens or modulator.

Then, the steepness of the emitting laser beam L1 will be described with reference to FIG. 2 .

2 is a diagram schematically illustrating a short-axis profile of an emitting laser beam.

Referring to FIG. 2 , when the thin film T is crystallized, the output laser beam L1 is scanned while overlapping, so that a scan pitch is generated.

In the short-axis profile of the emitted laser beam, a difference in energy intensity between 10% and 90% of both ends is referred to as steepness.

When the energy difference due to the interval of the scan pitch is X, the energy difference according to the scan pitch can be obtained by Equation 1.

[Equation 1]

X = (Scan Pitch × Beam Intensity) / (Steepness × 1.25)

In order to reduce the energy difference due to the interval of the scan pitch, it is necessary to reduce the scan pitch and the intensity of the emitted laser beam or increase the stiffness. However, when the scan pitch is reduced, a problem of productivity deterioration occurs due to an increase in process time, and when the intensity of the emitted laser beam is reduced, energy may be insufficient during crystallization of the thin film T.

Accordingly, an increase in stiffness is required to improve streak unevenness caused by an energy difference according to a scan pitch interval.

As described above, the controller 600 collects the data of the stiffness of the emitted laser beam L1 digitized by the monitoring unit 400 and the short-axis peak data of the emitted laser beam L1 digitized by the inspection unit 500, , The collected data may be fed back to the optical system 200, and the optical system 200 may correct the stiffness of the emitted laser beam L1 by moving the positions of the plurality of lenses and the plurality of modulators according to the feedback data. In particular, among a plurality of lenses and a plurality of modulators, the stiffness of the emitted laser beam L1 can be corrected by adjusting the lens and modulator involved in the shortening of the emitted laser beam L1.

By correcting the stiffness, it is possible to improve streak unevenness caused by an energy difference according to a scan pitch interval.

Next, with reference to FIG. 3 , improvement of streaks of thin films according to correction of stiffness will be described.

FIG. 3(a) shows an image of a thin film before stiffness is corrected, and FIG. 3(b) shows an image of a thin film after stiffness is corrected.

Referring to FIG. 3 , it can be seen that the streak after correction for stiffness is improved compared to before correction for stiffness.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also made according to the present invention. falls within the scope of the rights of

100: laser generator 200: optical system
300: process chamber 400: monitoring unit
500: inspection unit 600: control unit

Claims (10)

A laser generator generating an incident laser beam;
An optical system that processes the incident laser beam to produce an outgoing laser beam;
A monitoring unit for monitoring the emitted laser beam;
A process chamber in which the emission laser beam is irradiated to crystallize a thin film; and
Including an inspection unit for inspecting the thin film in the process chamber,
The monitoring unit checks the shortening of the emitting laser beam and quantifies the steepness of the emitting laser beam;
The inspection unit inspects the thin film and digitizes a short axis peak of the emitted laser beam,
A laser crystallizer for correcting the stiffness of the emitted laser beam based on the digitized data of the stiffness and the digitized data of the shortened peak of the emitted laser beam. delete delete In paragraph 1,
The laser crystallization apparatus further includes a controller that collects the digitized data of the stiffness and the digitized data of the short-axis peak of the emitted laser beam. In paragraph 4,
The controller feeds back the collected data to the optical system. In paragraph 5,
The optical system includes a plurality of lenses and a plurality of modulators. In paragraph 6,
wherein the optical system corrects the stiffness of the emitted laser beam by moving the plurality of lenses and the plurality of modulators according to the fed back data. In paragraph 6,
The optical system further comprises a motor for moving the plurality of lenses and the plurality of modulators. In paragraph 1,
The optical system includes a reflection mirror for reflecting a portion of the emitted laser beam to the monitoring unit. A laser generator generating an incident laser beam;
An optical system that processes the incident laser beam to produce an outgoing laser beam;
a monitoring unit that checks the shortening of the emitting laser beam and quantifies the steepness of the emitting laser beam;
A process chamber in which the emitted laser beam is irradiated to crystallize a thin film;
An inspection unit for inspecting the thin film in the process chamber and digitizing a short-axis peak of the emission laser beam; and
A controller that collects the digitized data of the stiffness and the digitized data of the short-axis peak of the emitted laser beam, and feeds back the collected data to the optical system;
A laser crystallizer for correcting the stiffness of the output laser beam based on the fed back data.

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