| 摘要 |
A method for improved planarization of surface topographies encountered in semiconductor processing that involve the etch-back of exposed surfaces of an oxide of silicon and a spin-on-glass. The oxide of silicon is chosen to be oxygen-deficient and thus silicon-rich, with a spectroscopically-defined silicon richness coefficient CSR that is greater than 0, and preferably greater than 0.005. A fluorine-containing process gas such as CHF3 combined with one or more of CF4, C2F6 and SF6 can be used in the etch chemistry. Sensitivity of the etch rate to certain parameters, such as the relative surface area of the exposed oxide of silicon and the fraction of fluorine present, is either reduced or eliminated. Improvement and better control of planarization is achieved by the process, resulting in a widening of the etch-back process window.
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