| 摘要 |
A film thickness measuring method and apparatus sets forth a spectral reflectance ratio S(lambda) at a spot where the film to be measured is present and a spectral reflectance ratio R(lambda) at a spot where the film to be measured is not present are measured to determine a spectral reflectance ratio Rmeas(lambda)=S(lambda)/R(lambda). A theoretical value Rcalc(lambda) of the spectral reflectance ratio at an assumed film thickness d is determined, and an evaluation value Ed is determined from the total sum of differences between the value of Rmeas(lambda) and the value of Rcalc(lambda). Assuming that the spectral reflectance ratio Rmeas(lambdae) of the film is 1 (Rmeas(lambdae)=1), an evaluation value Enewd is determined. The film thickness d is changed to determine an evaluation function Enew(d). An evaluation function ratio PE(d) is determined from E(d)/Enew(d), and a film thickness d that gives a minimum value of the ratio PE(d) is determined to be a measured film thickness D.
|
