| 摘要 |
The present invention aims to provide a method to control a film thickness by a crystal oscillation type film thickness monitor with an improved error correction which is very precise, and an improved film thickness measurement which is very precise. The method of the present invention measures the film thickness of a thin film of a substrate for measurement on each of the different oscillation frequencies using a crystal vibrator for a prior measurement before a film formation process; calculates a ratio of the target film thickness measured by a crystal vibrator for a prior measurement, and an actual film thickness of the thin film for the substrate to measure on each of the different oscillation frequencies as the correction ratio; corrects the film thickness of the thin film of the substrate (for film formation) or the film formation speed by multiplying the film thickness of the thin film of the substrate (for film formation) measured by the crystal vibrator during film formation in the film formation process or the film formation speed by the correction ratio in accordance to the oscillation frequency of the correction ratio; and controls the film thickness. |
