Plasma-deposited silicon oxynitride (a-SiON:H) films for use as interlevel dielectrics.

This report summarizes the development of plasma-deposited amorphous oxygen-doped silicon nitride (oxygen doped SiNCAP) films for use as the interlevel dielectric on two-level metal codes produced at AT&T-TS-RD. We found that the electrical resistivity, dielectric breakdown field, deposition rate, and BHF etch rate, increase with increasing oxygen content. The film stress, static and dynamic dielectric constants, refractive index, hydrogen content, defect density, and sodium penetration resistance decrease with increasing oxygen content. Based on these results we chose an oxynitride film containing 17%O as the interlevel dielectric for TLM codes. The front probe yields were at least 5% higher for the oxynitride film than for the normal SiNCAP film. This yield increase is due to a lower stress and a lower defect density in the oxynitride than in the normal SiNCAP film. This improvement in yield did not affect the processing or reliability of the device.