Method for transferring a dummy wafer
AssigneesAsahi Glass Company, Limited, Tokai Carbon Co., Ltd.
InventorHiroshi Kojima
Life of this patent
Estimating the term…
Abstract
Dummy wafers of SiC having low light transmission properties to light from the light source of a photo-sensor are used, and when wafers undergoes a heat treatment, the dummy wafers are transferred from a wafer cassette to a wafer boat in which the number of dummy wafers and a state of arrangement of the wafers are detected or monitored.
Claims16
A method for transferring a dummy wafer of SiC from a wafer cassette to a wafer boat to be housed in a wafer heating apparatus, the method comprising the steps of:
- (a) removing the dummy wafer from the wafer cassette using a wafer transferring device;
- (b) transferring the dummy wafer to the wafer boat;
- (c) placing the dummy wafer in a wafer supporting slot in the wafer boat;
- and
- (d) monitoring whether the dummy wafer is correctly positioned within the wafer supporting slot using a photo-sensor and a light source during at least one of steps (a) through (c),
- wherein the dummy wafer has minimal transmittance to light from the light source of the photo-sensor.
A method for transferring a dummy wafer of SiC from a wafer boat after a heat treatment to a wafer cassette, the method comprising the steps of:
- (a) removing the dummy wafer from the wafer boat using a wafer transferring device;
- (b) transferring the dummy wafer to the wafer cassette;
- (c) placing the dummy wafer in the wafer cassette;
- and
- (d) monitoring whether the dummy wafer is correctly positioned within the wafer supporting slot using a photo-sensor and a light source during at least one of steps (a) through (c),
- wherein the dummy wafer has minimal transmittance to light from the light source of the photo-sensor.
A method for transferring a dummy wafer of SiC from a wafer cassette to a wafer boat to be housed in a wafer heating apparatus, and successively transferring the dummy wafer from the wafer boat after a heat treatment to the wafer cassette, the method comprising the steps of:
- (a) removing the dummy wafer from the wafer cassette using a wafer transferring device;
- (b) transferring the dummy wafer to the wafer boat;
- (c) placing the dummy wafer in a wafer supporting slot in the wafer boat;
- (d) removing the dummy wafer from the wafer boat;
- (e) transferring the dummy wafer to the wafer cassette;
- (f) placing the dummy wafer in the wafer cassette;
- (g) monitoring whether the dummy wafer is correctly positioned within the wafer supporting slot using a photo-sensor and a light source during at least one of steps (a) through (f),
- wherein the dummy wafer has minimal transmittance to light from the light source of the photo-sensor.
Dependencies are inferred from the claim text.