Silicon⁺- Post processing CMOS wafers to create integrated sensors, MEMS and electro-optic systems

Silicon based integrated circuit technology has shown astonishing progress scaling to smaller geometries as the industry follows Moore's predictions. However, in recent years the cost associated with staying at the leading edge of silicon IC technology has resulted in many companies being either unable, or unwilling, to afford the investment required. As a consequence some have decided to use foundry technology and/or diversify into new device types and associated novel application areas. All of these diverse Silicon+ technologies have one particular feature in common, namely they all use silicon as a platform for system integration with the added value being the innovation associated with post-processing and/or technology integration, which in many cases is realised on standard foundry technology. This paper examines many of the issues associated with integrating foundry and custom IC wafers with both new materials and technologies such as MEMS based sensors and actuators. In particular it examines the various options available for companies considering Silicon ⁺ technology applications and presents examples of successful applications of this approach. Some of these are illustrated below.