# US 10,872,767 B2 · Laser annealing apparatus, and fabrication methods of polycrystalline silicon thin film and thin film transistor

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- Number: US 10,872,767 B2
- Document ID: US10872767B2
- Status: Granted
- Kind: B2
- Application number: 15/696,814
- Filed: 2017-09-06
- Published: 2018-05-31
- Granted: 2020-12-22
- Earliest claimed: 2016-11-29
- Assignees: Boe Technology Group Co., Ltd.; Ordos Yuansheng Optoelecetronics Co., Ltd.
- Applicants: Boe Technology Group Co., Ltd.; Ordos Yuansheng Optoelectronics Co., Ltd.
- Inventors: Jingshuai Wang
- Web page: https://patentgrep.com/patent/US10872767B2

## CPC

- H10P 14/381: {Beam shaping, e.g. using a mask}
- B23K 26/0626: {Energy control of the laser beam (B23K26/0622 takes precedence)}
- B23K 26/0665: {by beam condensation on the workpiece, e.g. for focusing}
- B23K 26/0673: {into independently operating sub-beams, e.g. beam multiplexing to provide laser beams for several stations}
- B23K 26/127: {in an enclosure}
- B23K 26/128: {Laser beam path enclosures}
- G02B 19/0019: {having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors)}
- G02B 19/0023: {at least one surface having optical power}
- G02B 19/0047: {for use with a light source (G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005)}
- G02B 27/14: operating by reflection only
- H10D 30/0314: {of lateral top-gate TFTs comprising only a single gate}
- H10D 30/0316: {of lateral bottom-gate TFTs comprising only a single gate}
- H10D 30/0321: {comprising silicon, e.g. amorphous silicon or polysilicon}
- H10D 86/0229: {characterised by control of the annealing or irradiation parameters}
- H10D 86/0251: {characterised by increasing the uniformity of device parameters}
- H10P 14/24: using chemical vapour deposition [CVD]
- H10P 14/3411: {Silicon, silicon germanium or germanium}
- H10P 14/3454: {Amorphous}
- H10P 14/3456: {Polycrystalline}
- H10P 14/3816: {Pulsed laser beam}
- H10P 14/382: {Scanning of a beam}
- H10P 72/0436: {mainly by radiation}
- H01S 3/225: comprising an excimer or exciplex
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL

## Abstract

A laser annealing apparatus, a fabrication method of a polysilicon thin film, and a fabrication method of a thin film transistor are provided. The laser annealing apparatus includes: a laser generator, an optical system and an annealing chamber. The laser generator is configured to emit a laser beam, and the laser beam is guided to the annealing chamber via the optical system. The optical system includes a beam splitter, the beam splitter decomposes the laser beam into a first beam and a second beam, an energy density of the first beam is greater than an energy density of the second beam, and the first beam and the second beam are guided into the annealing chamber for laser annealing.

## Claims

### Claim 1

A laser annealing apparatus, comprising: a laser generator, an optical system and an annealing chamber, wherein,
the laser generator is configured to emit a laser beam, the laser beam is guided to the annealing chamber after passing the optical system;
the optical system includes a beam splitter, the beam splitter decomposes the laser beam into a first beam and a second beam, an energy density of the first beam is greater than an energy density of the second beam, and the first beam and the second beam are guided into the annealing chamber for laser annealing;
a side of the annealing chamber is provided with a first slit and a second slit, the first beam enters into the annealing chamber through the first slit, the second beam enters into the annealing chamber through the second slit, the first slit and the second slit are configured that the first slit is opened while the second slit is closed, and the second slit is opened while the first slit is closed;
the optical system further includes a light uniformization component, a focus mirror and a reflection mirror, and in a propagation direction of the laser beam, the light uniformization component and the focus mirror are provided in front of the beam splitter, and the reflection mirror is provided after the beam splitter;
the light uniformization component includes a short axis light uniformization element, a collection element, a long axis light uniformization element, a long axis expansion element and a short axis contraction element; and
in the propagation direction of the laser beam, the short axis light uniformization element, the collection element, the long axis light uniformization element, the long axis expansion element, and the short axis contraction element are sequentially arranged in this order;
the focus mirror includes a long axis focus mirror, a short axis focus mirror, and an auxiliary focus mirror;
in the propagation direction of the laser beam, the long axis focus mirror is located between the long axis light uniformization element and the long axis expansion element;
in the propagation direction of the laser beam, the short axis focus mirror is located between the short axis contraction element and the beam splitter; and
in the propagation direction of the laser beam, the auxiliary focus mirror is located behind the beam splitter and the reflection mirror.

### Claim 2 (depends on 1)

The laser annealing apparatus according to claim 1, wherein, an energy of the first beam is greater than an energy of the second beam.

### Claim 3 (depends on 1)

The laser annealing apparatus according to claim 1, wherein, the laser generator is an excimer laser.

### Claim 4 (depends on 3)

The laser annealing apparatus according to claim 3, wherein, the excimer laser includes an inert gas excimer laser, an inert gas halide excimer laser, a mercury halide excimer laser, an inert gas oxide excimer laser and a polyatomic excimer laser.

### Claim 5 (depends on 1)

The laser annealing apparatus according to claim 1, wherein,
the reflection mirror includes a first reflection mirror, a second reflection mirror and a third reflection mirror;
the first beam is reflected by the first reflection mirror and the second reflection mirror and then is guided to the annealing chamber; and
the second beam is reflected by the third reflection mirror and then is guided to the annealing chamber.

### Claim 6 (depends on 1)

The laser annealing apparatus according to claim 1, comprising at least two laser generators respectively emitting a first laser beam and a second laser beam, the first laser beam and the second laser beam being combined to obtain the laser beam.

### Claim 7 (depends on 6)

The laser annealing apparatus according to claim 6, wherein, an energy of the first laser beam and an energy of the second laser beam are both 1000 mj, an energy of the first beam is 1200 mj, and an energy of the second beam is 800 mj.

### Claim 8 (depends on 1)

The laser annealing apparatus according to claim 1, further comprising a carrier provided in the annealing chamber for carrying a substrate, and a first detector and a second detector respectively provided on both ends of the carrier;
wherein, the first detector and the second detector respectively detect the energy density of the first beam and the energy density of the second beam.

### Claim 9 (depends on 1)

The laser annealing apparatus according to claim 1, wherein, the annealing chamber is filled with a protective gas.

### Claim 10 (depends on 1)

The laser annealing apparatus according to claim 1, further comprising a first attenuator and a second attenuator, wherein, the first attenuator and the second attenuator respectively attenuate the energy density of the first beam and the energy density of the second beam.

### Claim 11

A laser annealing apparatus, comprising: a laser generator, an optical system and an annealing chamber, wherein,
the laser generator is configured to emit a laser beam, the laser beam is guided to the annealing chamber after passing the optical system;
the optical system includes a beam splitter, the beam splitter decomposes the laser beam into a first beam and a second beam, an energy of the first beam is greater than an energy of the second beam, and the first beam and the second beam are guided into the annealing chamber for laser annealing; and
a side of the annealing chamber is provided with a first slit and a second slit, the first beam enters into the annealing chamber through the first slit, the second beam enters into the annealing chamber through the second slit, the first slit and the second slit are configured that the first slit is opened while the second slit is closed, and the second slit is opened while the first slit is closed,
the optical system further includes a light uniformization component, a focus mirror and a reflection mirror, and in a propagation direction of the laser beam, the light uniformization component and the focus mirror are provided in front of the beam splitter, and the reflection mirror is provided after the beam splitter;
the light uniformization component includes a short axis light uniformization element, a collection element, a long axis light uniformization element, a long axis expansion element and a short axis contraction element; and
in the propagation direction of the laser beam, the short axis light uniformization element, the collection element, the long axis light uniformization element, the long axis expansion element, and the short axis contraction element are sequentially arranged in this order;
the focus mirror includes a long axis focus mirror, a short axis focus mirror, and an auxiliary focus mirror;
in the propagation direction of the laser beam, the long axis focus mirror is located between the long axis light uniformization element and the long axis expansion element;
in the propagation direction of the laser beam, the short axis focus mirror is located between the short axis contraction element and the beam splitter; and
in the propagation direction of the laser beam, the auxiliary focus mirror is located behind the beam splitter and the reflection mirror.