METHOD OF CONTROLLING THE FILM PROPERTIES OF A CVD-DEPOSITED SILICON NITRIDE FILM

Fecha de publicación: 09/02/2006
Fuente: WIPO "miel"
We have discovered that adding H2 to a precursor gas composition including SiH4, NH3, and N2 is effective at improving the wet etch rate and the wet etch rate uniformity across the substrate surface off a-SiNx:H films which are deposited on a substrate by PECVD. Wet etch rate is an indication of film density. Typically, the lower the wet etch rate, the denser the film. The addition of H2 to the SiH4 / NH3 / N2 precursor gas composition did not significantly increase the variation in deposited film thickness across the surface of the substrate. The a-SiNx:H films described herein are particularly useful as TFT gate dielectrics in the production of flat panel displays. The uniformity of the film across the substrate enables the production of flat panel displays having surface areas of 25,000 cm2 and larger.