On the Limiting of Minimum Size of SOS/MOS Devices by the Microtwins in the Silicon

Plan view TEM micrographs of operating SOS/MOS transistors clearly show the extent and distribution of the silicon microtwins throughout the junction and channel regions. Numerous microtwins are found in the junctions without causing any detectible electrical problems. It is suggested that these defects will probably not be a fundamental limitation to geometrical reduction of SOS/ MOS devices. The twins cause a dependence of field effect mobility on current flow direction.