The objective of this program is to develop asilicon-on-insulator technology (SOI) using CVD diamond films asinsulators. Such structures should permit the fabrication of integratedcircuits with performance capabilities superior to those fabricated usingconventional SOI structures including silicon-on-Sapphire (SOS), SIMOX,Epitaxial Layer Overgrowth (ELO) and Bond Etchback SOI (BESOI). Diamond insulating substrates should extend the radiation tolerance of existingSOI technologies due to their high transparency to radiation. TheSilicon-on-diamond (SOD) technology is the only SOI approach that allowsfor efficient heat dissipation from the active regions of integratedcircuits as a result of the exceptional thermal conductivity of diamond. Diamond films provide unsurpassed thermal conductivity of 20W-cm-1K-1,excellent radiation resistance of greater than 107 RAD for SOD devicesand high electrical resistivity of greater than 1 x 1014 Ohm-cm. The goalof this project is to successfully fabricate SOD wafers using a waferbonding process and to have good performance of the SOD wafers in termsof low leakage, high thermal conductivity and high radiation resistance.These performance advantages will be available for use in CMOSstructures, analog circuits, BICMOS structures and radiation hardcircuits. SOD wafers have application within the large SOI market wherethere is a demand for radiation hardness, high temperature performanceand high heat dissipation from the devices. One example of theapplication of SOD wafers is to use them as substrates for highperformance ICs used in space, in the atmosphere and on the ground. Dueto the superior heat dissipation of SOD substrates, enhanced performancecan be achieved in technologies such as dense bipolar integrated circuitsand CMOS devices. Problems with short-channel effects and leakage in CMOSdevices make a change from bulk silicon to SOD wafers desirable.
