Film thickness measurement method, epitaxial wafer production process and epitaxial wafer
AssigneeSumco Corporation
InventorKazuhiro Ohkubo
Life of this patent
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Abstract
A film thickness measurement method for measuring a change in film thickness of 0.3 μm or less in a silicon wafer by FTIR, having an auxiliary film formation step for depositing an auxiliary film for measurement on a surface to be measured for the change in film thickness, an auxiliary film thickness measurement step for measuring the film thickness of the auxiliary film, a measurement step for measuring the film thickness of the auxiliary film after the change in film thickness, and a calculation step for calculating a change in film thickness of a back surface deposit from the result of the measurement step and the result of the auxiliary film thickness measurement step.
Claims8
A film thickness measurement method for measuring a change in film thickness of 0.3 μm or less in a silicon wafer by FTIR, comprising:
- an auxiliary film formation step for depositing an auxiliary film for measurement of a prescribed film thickness on a side to be measured for the change in film thickness;
- an auxiliary film thickness measurement step for measuring the film thickness of the auxiliary film;
- a measurement step for measuring the film thickness of the auxiliary film after the change in film thickness;
- and
- a calculation step for calculating a change in film thickness from the result of the measurement step and the result of the auxiliary film thickness measurement step.
An epitaxial wafer production process in which an epitaxial layer is deposited on the front surface of a wafer, comprising:
- an auxiliary film formation step for depositing an auxiliary film for measurement of a prescribed film thickness on the back surface of the wafer;
- an auxiliary film thickness measurement step for measuring the film thickness of the auxiliary film by FTIR;
- a front surface epitaxial layer deposition step for depositing an epitaxial layer on the front surface of the wafer;
- a measurement step for measuring the film thickness of the auxiliary film caused by a back surface deposit on the auxiliary film by FTIR after the front surface epitaxial layer deposition step;
- and
- a calculation step for calculating a change in film thickness of 0.3 μm or less caused by the back surface deposit from the result of the measurement step and the result of the auxiliary film thickness measurement step.
Dependencies are inferred from the claim text.