# US 11,908,703 B2 · Light irradiation type heat treatment method

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- Number: US 11,908,703 B2
- Document ID: US11908703B2
- Status: Granted
- Kind: B2
- Application number: 17/370,026
- Filed: 2021-07-08
- Published: 2022-02-03
- Granted: 2024-02-20
- Earliest claimed: 2020-07-31
- Assignees: SCREEN Holdings Co., Ltd.
- Applicants: SCREEN Holdings Co., Ltd.
- Inventors: Mao Omori; Kazuhiko Fuse
- Web page: https://patentgrep.com/patent/US11908703B2

## CPC

- H10P 95/90: Thermal treatments, e.g. annealing or sintering
- H05B 3/0047: {for semiconductor manufacture}
- H10P 34/422: {using incoherent radiation}
- H10P 72/0432: {mainly by conduction}
- H10P 72/0436: {mainly by radiation}
- H10P 72/7602: {the wafers being placed on a robot blade or gripped by a gripper for conveyance}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL

## Abstract

Heating treatment is performed on multiple dummy wafers to preheat in-chamber structures including a susceptor and the like prior to the treatment of a semiconductor wafer to be treated. The first few ones of the multiple dummy wafers are heated to a first heating temperature by light irradiation from halogen lamps, and are thereafter irradiated with a flash of light. The subsequent few ones of the multiple dummy wafers are heated to a second heating temperature lower than the first heating temperature by light irradiation from the halogen lamps, and are thereafter irradiated with a flash of light. This stabilizes the temperature of the in-chamber structures in a shorter time with fewer dummy wafers because the dummy wafers are heated to the high temperature and thereafter heated to the low temperature.

## Claims

### Claim 1

A method of irradiating a substrate with light to heat the substrate, said method comprising the steps of:
(a) sequentially transporting multiple dummy wafers into a chamber and placing the dummy wafers on a susceptor before a substrate to be treated is transported into said chamber;
(b) irradiating a back surface of each dummy wafer in a first group among said multiple dummy wafers with light from a continuous lighting lamp to heat each dummy wafer in the first group to a first heating temperature, and thereafter irradiating a front surface of each dummy wafer in the first group with a flash of light from a flash lamp to heat each dummy wafer in the first group;
(c) measuring, as a judgment temperature, a predetermined temperature at a time when a predetermined time period has elapsed since turning off of said continuous lighting lamp and said flash lamp upon completion of heating of each dummy wafer in the first group; and
(d) irradiating a back surface of each dummy wafer in a second group among said multiple dummy wafers with light from said continuous lighting lamp to heat each dummy wafer in the second group to a second heating temperature lower than said first heating temperature, and thereafter irradiating a front surface of each dummy wafer in the second group with a flash of light from said flash lamp to heat each dummy wafer in the second group, said step (d) being started after said judgment temperature falls within a predetermined range with respect to a target temperature,
wherein said judgment temperature is a temperature of the back surface of each dummy wafer in the first group or an atmosphere temperature in said chamber.

### Claim 2 (depends on 1)

The method according to claim 1,
wherein said second heating temperature is a temperature to which said substrate to be treated is heated by irradiating said substrate with light from said continuous lighting lamp.

### Claim 3 (depends on 1)

The method according to claim 1,
wherein said first heating temperature is 5° to 100° C. higher than said second heating temperature.

### Claim 4 (depends on 1)

The method according to claim 1,
wherein said first heating temperature is decreased stepwise in said step (b).

### Claim 5 (depends on 1)

The method according to claim 1,
wherein the number of dummy wafers in the first group is in the range of 1 to 10.

### Claim 6 (depends on 1)

The method according to claim 1,
wherein the number of dummy wafers in the second group is in the range of 1 to 10.

### Claim 7

A method of irradiating a substrate with light to heat the substrate, said method comprising the steps of:
(a) sequentially transporting multiple dummy wafers into a chamber and placing the dummy wafers on a susceptor before a substrate to be treated is transported into said chamber;
(b) irradiating a back surface of each dummy wafer in a first group among said multiple dummy wafers with light from a continuous lighting lamp, and thereafter irradiating a front surface of each dummy wafer in the first group with a flash of light from a flash lamp to heat each dummy wafer in the first group to a first heating temperature;
(c) measuring, as a judgment temperature, a predetermined temperature at a time when a predetermined time period has elapsed since turning off of said continuous lighting lamp and said flash lamp upon completion of heating of each dummy wafer in the first group; and
(d) irradiating a back surface of each dummy wafer in a second group among said multiple dummy wafers with light from said continuous lighting lamp, and thereafter irradiating a front surface of each dummy wafer in the second group with a flash of light from said flash lamp to heat each dummy wafer in the second group to a second heating temperature lower than said first heating temperature, said step (d) being started after said judgment temperature falls within a predetermined range with respect to a target temperature,
wherein said judgment temperature is a temperature of the back surface of each dummy wafer in the first group or an atmosphere temperature in said chamber.