Silicon on sapphire

The advantage of sapphire is that it is an excellent electrical insulator, preventing stray currents caused by radiation from spreading to nearby circuit elements.

SOS faced early challenges in commercial manufacturing because of difficulties in fabricating the very small transistors used in modern high-density applications.

This is because the SOS process results in the formation of dislocations, twinning and stacking faults from crystal lattice disparities between the sapphire and silicon.

In 1963, Harold M. Manasevit was the first to document epitaxial growth of silicon on sapphire while working at the Autonetics division of North American Aviation (now Boeing).

These RFICs are designed for commercial RF applications such as mobile handsets and cellular infrastructure, broadband consumer and DTV, test and measurement, and industrial public safety, as well as rad-hard aerospace and defense markets.