Ultra low stress silicon-rich nitride films for micro structure fabrication

We have set up a LPCVD system enabling us to deposit ultra low stress (less than or equal to 10Mpa) single layer silicon-rich nitride film at high temperature (less than or equal to 900 degrees C) with fast deposition rate for micro-structures fabrication. Silicon-rich nitride films deposited at high temperature have ultra low stress and are relatively independent of silicon and nitrogen containing gas-flow ratio during deposition. Deposition process parameters were optimized employing Taguchi method and no post deposition process is required to obtain low stress films. Detailed study of the effects of deposition parameters on film properties is also presented. The high temperature deposited ultra low stress silicon rich nitride film is resistant to all commonly used silicon anisotropic etchants (KOH, EDP, TMAH, Hydrazine), an ideal material for various micro-structures fabrication.