Computer Hardware Terms, Glossary and Dictionary

Silicon-On-Insulator (SOI), developed by IBM, is a chipmaking technology that builds transistors on a thinner layer of silicon than previously possible, improving chip performance and reducing power consumption. SOI is a layered structure consisting of a thin layer of silicon, from 50 nm to 100 µm, which is created on an insulating substrate, which is usually sapphire or a silicon with an insulating layer of silicon dioxide 80 nm thick on its surface. This process reduces the amount of electrical charge that the transistor has to move during a switching operation, increasing speed (up to 15%) and reducing switching energy (up to 20%) over CMOS-based chips. SOI chips cost more to produce and are generally used for high-end applications.

Related Terms

SOI: Silicon-On-Insulator