# US 12,191,323 B2 · Display device manufacturing apparatus and method

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- Number: US 12,191,323 B2
- Document ID: US12191323B2
- Status: Granted
- Kind: B2
- Application number: 17/205,509
- Filed: 2021-03-18
- Published: 2022-02-17
- Granted: 2025-01-07
- Earliest claimed: 2020-08-14
- Assignees: Samsung Display Co., Ltd.
- Applicants: Samsung Display Co., Ltd.
- Inventors: Kihwan Seok; Hoonchul Ryoo
- Web page: https://patentgrep.com/patent/US12191323B2

## CPC

- H10D 86/0229: {characterised by control of the annealing or irradiation parameters}
- H10D 86/0212: {comprising manufacture, treatment or coating of substrates}
- H10D 86/0251: {characterised by increasing the uniformity of device parameters}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A display device manufacturing method includes annealing a display substrate by irradiating a laser to the display substrate in different energy values, measuring a transmittance of the annealed display substrate, and determining an optimal crystallization value of the display substrate based on the transmittance, wherein the determining of the optimal crystallization value includes calculating an absorbance of the display substrate for each energy value of the laser based on the transmittance, calculating a band gap energy of the annealed display substrate for each energy value of the laser based on the absorbance, and determining an energy value of the laser corresponding to a minimum value of the band gap energy as the optimal crystallization value. Also provided is a display device manufacturing apparatus that may implement the manufacturing method.

## Claims

### Claim 1

A display device manufacturing method comprising:
annealing a display substrate by irradiating a laser to the display substrate in different energy values;
measuring a transmittance of the annealed display substrate; and
determining an optimal crystallization value of the display substrate based on the transmittance,
wherein the annealing of the display substrate comprises:
dividing the display substrate into a plurality of areas; and
irradiating the laser having different energy values corresponding to the plurality of areas, respectively, of the display substrate,
wherein the determining of the optimal crystallization value comprises:
calculating an absorbance of the annealed display substrate for each energy value of the laser based on the transmittance;
calculating a band gap energy of the annealed display substrate for each energy value of the laser based on the absorbance; and
determining an energy value of the laser corresponding to a minimum value of the band gap energy as the optimal crystallization value.

### Claim 2 (depends on 1)

The display device manufacturing method of claim 1, wherein the annealing of the display substrate and the measuring of the transmittance are simultaneously performed.

### Claim 3 (depends on 1)

The display device manufacturing method of claim 1, wherein the annealing of the display substrate comprises irradiating the laser having the different energy values corresponding to a plurality of areas, respectively, of the display substrate.

### Claim 4 (depends on 3)

The display device manufacturing method of claim 3, wherein the energy values of the laser satisfy an arithmetic progression from a lowest energy value to a highest energy value.

### Claim 5 (depends on 3)

The display device manufacturing method of claim 3, wherein the measuring of the transmittance comprises measuring transmittances of the plurality of areas of the display substrate.

### Claim 6 (depends on 1)

The display device manufacturing method of claim 1, further comprising measuring a reflectance of the annealed display substrate.

### Claim 7 (depends on 6)

The display device manufacturing method of claim 6, wherein the calculating of the absorbance comprises calculating an absorbance for each energy value of the laser based on the transmittance and the reflectance.

### Claim 8 (depends on 1)

The display device manufacturing method of claim 1, wherein the calculating of the band gap energy is performed by using a Tauc plot based upon the absorbance.

### Claim 9 (depends on 8)

The display device manufacturing method of claim 8, wherein the band gap energy corresponds to a point where a straight line extending from a linear section of the Tauc plot meets an energy axis.

### Claim 10 (depends on 1)

The display device manufacturing method of claim 1,
wherein a median value of the energy values of the laser is equal to the optimal crystallization value.

### Claim 11 (depends on 10)

The display device manufacturing method of claim 10, wherein
a part of the energy values of the laser decrease by predetermined energy intervals from the median value, and
another part of the energy values of the laser increase by predetermined energy intervals from the median value.

### Claim 12 (depends on 1)

The display device manufacturing method of claim 1, further comprising moving the display substrate.

### Claim 13 (depends on 12)

The display device manufacturing method of claim 12, wherein the annealing of the display substrate and the measuring of the transmittance are sequentially performed while the display substrate moves.

### Claim 14 (depends on 1)

The display device manufacturing method of claim 1, wherein:
the transmittance is measured at a wavelength including ultraviolet light;
the absorbance is calculated based on the transmittance at the wavelength including ultraviolet light.