Semi-Insulating Silicon Substrates

The growth in voice, video and data communications has spurred the development of a wide range of high-speed devices and circuits required to achieve continually increasing bandwidth. Traditionally III-V based circuits have been used for theseapplications because of their intrinsic properties and availability of a semi-insulating (SI) substrates. SI substrates permit simple integration of passive and active devices, greatly enhancing isolation at RF frequencies. However, III-V circuits arenot suitable for a wide range of applications that require lower cost or very high integration levels. This is especially true in BiCMOS circuits that integrate analog and digital functions. These circuits are included in an ever-increasing number ofsystems employed by both the military and commercial sectors. It is clear that a SI silicon substrate that meets the other requirements of the silicon world would provide a wide range of advantages to silicon-based RF integrated circuits. These could beused for both silicon and SiGe circuits and would permit realization of the full advantages of monolithic integration of these devices and circuits. This proposal describes a new approach to making large area, true semi-insulating silicon substrates.Greatly reduced costs and wide spread use of RF integrated circuits in Government and commercial applications based on the use of a semi-insulating silicon substrate.