To: MEMS researchers and users From: S.H. Jones, Department of Electrical Engineering University of Virginia, Charlottesville, VA shj2n@virginia.edu We have recently completed a series of optical characteriztions on Ultra-Thin Silicon Substrates supplied by Virginia Semiconductor Incorporated. These substrates range in thickness from 4.0 - 150 um in thickness, and 1.0 - 4.0 inches in diameter. They are doulble-side polished. The wafers have been analysed using our recently developed optical micrometer and TTV system, as well as a spectrophotometer. Also, surface profiling for microroughness, and dicing for fracturing behavior have been looked at. The 4-150 um thick wafers consistently have total thickness variation (T TV) on the order of 2 um, microroughness less than 25A, and can be diced into at least 1 mil strips without fracturing. I believe these Ultra-Thin Substrates may be ideal for novel MEMS processing. If you are interested in working with me to use these substrates in a MEMs process please contact me at (804) 924-6080 or shj2n@virginia.edu.