Quasi-SOI MOSFETs using selective epitaxy and polishing

A Quasi-SOI MOSFET structure has been fabricated in which the drain-side channel is placed over oxide while the source-side channel is left connected to the substrate. This device has many of the advantages of SOI MOSFET without some of its problems. In particular, the drain breakdown voltage is found to improve over both the bulk and the complete-SOI counterparts. It is confirmed that the maximum lateral electric field is lower in the SOI channel than in same-size bulk device. The selective epitaxy and polishing technology combination used here makes it possible to fabricate all device types ranging from bulk to quasi-SOI to complete SOI on the same substrate, thus facilitating meaningful comparative studies.<>