Materials, device and gate oxide integrity evaluation of SIMOX and bonded SOI wafers

In this paper, we will review our recent material and electrical device results on SIMOX and BESOI wafers. The substrates were obtained from 2 SIMOX suppliers (IBIS and SOITEC) and one bonded supplier (HDOS). Substrates were routinely obtained over a period of more than two years and this has given us some insight into the various manufacturers quality and reproducibility as well as improvement efforts. The material parameters such as film uniformity, contamination, defects, and wafer warp and bow will be discussed. In addition, the integrity of gate oxides grown on these substrates will be compared to those grown on bulk wafers. Device results such as threshold voltage control (Vt) and subthreshold leakage for devices built on SIMOX and BESOI wafers will be compared. These results have been obtained from several lots processed in our line and thus represent variations in both the material and the process.