The effect of 1300-1380 degrees C anneal temperatures and material contamination on the characteristics of CMOS/SIMOX devices

Abstract

The characteristics of CMOS transistors fabrication on silicon implanted with oxygen (SIMOX) materials were measured as a function of the silicon superficial layer contamination levels. In addition, postimplant anneal temperatures of 1300 degrees C, 1350 degrees C, and 1380 degrees C were examined. It is found that the transistor leakage currents as well as the integrity of the gate oxide and implanted SIMOX oxide are functions of the carbon content in the starting material. Leakage currents below 1.0*10/sup -12/ A/ mu m of channel width have been measured when the carbon concentration is reduced to 2*10/sup 18//cm/sup 2/. In addition, the integrity of the transistor gate dielectric, SIMOX implanted oxide, and oxygen precipitate density are seen to be a function of the postimplant anneal temperature. A gate dielectric breakdown field of 10 MV/cm has been achieved when the postimplant temperature is increased to 1380 degrees C. >