HEAT TREATMENT APPARATUS AND HEAT TREATMENT METHOD FOR HEATING SUBSTRATE BY IRRADIATING SUBSTRATE WITH FLASHES OF LIGHT

• US 20120076477A1
• Filed: 07/07/2011
• Published: 03/29/2012
• Est. Priority Date: 09/28/2010
• Status: Active Grant

• Current Assignee: SCREEN Holdings Co., Ltd.
• Original Assignee: SCREEN Holdings Co., Ltd.
• Inventors: KUROIWA, Toru
• Granted Patent: US 9,025,943 B2
• Time in Patent Office: Days
• US Class Current: 392/416
• CPC Class Codes: F27B 17/0025 Especially adapted for treating semiconductor wafers
• CPC Class Codes: F27B 5/18 Arrangement of controlling, monitoring, alarm or like devices
• CPC Class Codes: F27D 2019/0003 Monitoring the temperature or a characteristic of the charge and using it as a controlling value
• CPC Class Codes: G01J 5/0007 of wafers or semiconductor substrates, e.g. using Rapid Thermal Processing
• CPC Class Codes: G01J 5/026 Control of working procedures of a pyrometer, other than calibration; Bandwidth calculation; Gain control
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/67248 Temperature monitoring

Abstract

Radiant energy from a semiconductor wafer which is determined from the theoretical value of black body radiation and the actually measured result of an output from a photodiode are brought into correspondence with each other, and a table showing a correlation therebetween is acquired and stored on a magnetic disk. When a semiconductor wafer to be treated is irradiated with flashes of light from flash lamps, the photodiode receives radiant light emitted from the semiconductor wafer. A controller determines, from the output from the photodiode, the radiant energy emitted per unit time from the semiconductor wafer irradiated with flashes of light, based on the acquired table. The controller further determines the surface temperature of the semiconductor wafer from the determined radiant energy.

Claims

1. A heat treatment apparatus for heating a substrate by irradiating the substrate with flashes of light, comprising:

a chamber for receiving a substrate;

a holder for holding the substrate within said chamber;

a flash lamp for irradiating the substrate held by said holder with flashes of light;

a photodiode for receiving radiant light emitted from the substrate held by said holder;

a storage part for storing a table showing a correlation between radiant energy per unit time from the substrate and an output from said photodiode;

an energy calculating part for determining, from the output from said photodiode, the radiant energy emitted per unit time from the substrate irradiated with flashes of light from said flash lamp, based on said table; and

a temperature determining part for determining the surface temperature of the substrate from the radiant energy per unit time from the substrate determined by said energy calculating part.

2. The heat treatment apparatus according to claim 1, further comprising:

an insulated-gate bipolar transistor for establishing and interrupting a current flowing to said flash lamp; and

an IGBT controller for switching OFF said insulated-gate bipolar transistor when the surface temperature of the substrate determined by said temperature determining part reaches a predetermined value.

3. The heat treatment apparatus according to claim 1, further comprising:

an insulated-gate bipolar transistor for establishing and interrupting a current flowing to said flash lamp; and

an IGBT controller for switching OFF said insulated-gate bipolar transistor when the radiant energy per unit time from the substrate determined by said energy calculating part reaches a predetermined value.

4. The heat treatment apparatus according to claim 1, further comprising:

an insulated-gate bipolar transistor for establishing and interrupting a current flowing to said flash lamp; and

an IGBT controller for switching OFF said insulated-gate bipolar transistor when total radiant energy reaches a predetermined value, the total radiant energy being determined from the radiant energy per unit time from the substrate determined by said energy calculating part.

5. The heat treatment apparatus according to claim 1, wherein

said storage part stores a table showing a correlation between radiant energy per unit time from the substrate and an output from said photodiode, the radiant energy per unit time from the substrate being determined from the theoretical value of the energy of black body radiation and the emissivity of the substrate.

6. The heat treatment apparatus according to claim 1, wherein

said storage part stores a table showing a correlation between radiant energy per unit time from the substrate measured with a pyrometer and an output from said photodiode.

7. The heat treatment apparatus according to claim 1, wherein

said flash lamp is a xenon flash lamp, and

said photodiode has a measuring wavelength of not less than 3 μ

m.

8. The heat treatment apparatus according to claim 1, further comprising

a sampling part including:

a current-to-voltage converter circuit for converting a current signal generated by said photodiode into a voltage signal;

an amplifier circuit for amplifying the voltage signal outputted from said current-to-voltage converter circuit;

an A-D converter for converting the voltage signal amplified by said amplifier circuit into a digital signal; and

a one-chip microcomputer for sampling the digital signal outputted from said A-D converter at predetermined time intervals to sequentially store sampled data in a memory.

9. The heat treatment apparatus according to claim 1, further comprising

a display part for displaying the surface temperature of the substrate determined by said temperature determining part.

10. A method of heating a substrate by irradiating the substrate with flashes of light, comprising the steps of:

(a) acquiring a table showing a correlation between radiant energy per unit time from a substrate and an output from a photodiode receiving radiant light emitted from the substrate;

(b) irradiating the substrate with flashes of light from a flash lamp;

(c) determining, from the output from said photodiode, the radiant energy emitted per unit time from the substrate irradiated with flashes of light, based on said table; and

(d) determining the surface temperature of the substrate from the radiant energy per unit time from the substrate determined in said step (c).

11. The method according to claim 10, wherein

an insulated-gate bipolar transistor for establishing and interrupting a current flowing to said flash lamp is turned OFF when the surface temperature of the substrate determined in said step (d) reaches a predetermined value.

12. The method according to claim 10, wherein

an insulated-gate bipolar transistor for establishing and interrupting a current flowing to said flash lamp is turned OFF when the radiant energy per unit time from the substrate determined in said step (c) reaches a predetermined value.

13. The method according to claim 10, wherein

an insulated-gate bipolar transistor for establishing and interrupting a current flowing to said flash lamp is turned OFF when total radiant energy reaches a predetermined value, the total radiant energy being determined from the radiant energy per unit time from the substrate determined in said step (c).

14. The method according to claim 10, wherein

a table showing a correlation between radiant energy per unit time from the substrate and an output from said photodiode is acquired in said step (a), the radiant energy per unit time from the substrate being determined from the theoretical value of the energy of black body radiation and the emissivity of the substrate.

15. The method according to claim 10, wherein

a table showing a correlation between radiant energy per unit time from the substrate measured with a pyrometer and an output from said photodiode is acquired in said step (a).

16. The method according to claim 10, wherein

said flash lamp is a xenon flash lamp, and

said photodiode has a measuring wavelength of not less than 3 μ

m.