Metal-induced laterally crystallized polycrystalline silicon for integrated sensor applications

A novel metal-induced lateral crystallization (MILC) technique, involving a low temperature crystallization step followed by a high temperature recrystallization step, has been applied to the formation of polycrystalline silicon (poly-Si) with enhanced material characteristics. A range of devices, including piezo-resistors, thermistors, resistors and thin-film transistors, has been fabricated both on MILC and regular low-pressure chemical vapor deposited (LPCVD) poly-Si. Compared to the latter, MILC poly-Si leads to much improved device performance. The piezo-resistive gauge factor of MILC poly-Si is at least double that of LPCVD poly-Si, with a maximum value of 60 measured, higher mobility, steeper subthreshold slope, lower threshold voltage, and higher on-off current ratio have been obtained for thin-film transistors realized on MILC poly-Si that those realized on LPCVD poly-Si. A variety of sensing and electronic devices based on MILC poly-Si can be simultaneously realized, thus making MILC an enabling technology for integrated silicon sensor applications.