Advanced Metal Oxide Semiconductor and Bipolar Devices on Bonded Silicon‐on‐Insulators

Abstract

Silicon-on-insulator devices have problems with both performance and cost. We developed three advanced evices on bonded SOI produced using pulse-field-assisted bonding and selective polishing in an attempt to solve these problems. We tightly bonded highly implanted wafers, epitaxial wafers, and wafers covered with smoothed CVD oxide at emperatures below 1000 ~ We uniformly thinned bonded wafers by grinding, polishing, resistivity-sensitive etching, or selective polishing. We formed buried layers and buried electrodes by bonding and polishing techniques. Our high speed epitaxial-base transistor on 1-~m thick SOI has a cutoff frequency of 32 GHz. Our lateral bipolar transistor with a thin base on 0.15-~m thick SOI had a cutoff frequency of 4 GHz. A double-gate MOSFET on 60-nm thick SOI had a transconductance of more than twice that of a conventional SOI MOSFET. This paper discusses further advantages of bonded SOI techniques. Silicon-on-insulator (SOi) technology based on wafer bonding is an emerging technology for high-performance integrated circuits. The most useful SOI properties are a direct result of the ability to provide total electrical isola-tion. The quality of bonded SOI is similar to that of conven-tional bulk Si wafers, and bonded SOI usually can be used