Influence of low dielectric SiOF film on metal oxide semiconductor field effect transistor characteristics and its impact on circuit performance

A low dielectric fluorine-doped silicon oxide (SiOF) film, which was produc ed by adding C2F6 to the conventional chemical vapor deposited oxide, was a pplied to a 0.35 mu m complementary metal oxide semiconductor (CMOS) and it s influence on metal oxide semiconductor field effect transistor characteri stics was analyzed. A shift of the transconductance was observed when the S iOF film was used as an intermediate dielectric and the Si3N4 film as the d ielectric on the metal. An improvement in speed of 13% due to the SiOF film was experimentally confirmed under the condition where the transconductanc e does not show a shift. Using circuit simulations, the necessity for such low dielectric films as the SiOF film, on the scaling trend in the improvem ent of circuit performance, was clearly shown and was also emphasized from the point of view of power reduction. It was revealed that circuit speed an d power consumption of 0.35 mu m CMOS were degraded if the SiOF film was no t used, because the improvement of the transistor performance did not overc ome the increase in interconnect capacitance due to the increase in the adj acent interconnect capacitance component.