Fabrication and characterization of nickel-induced laterally crystallized polycrystalline silicon piezo-resistive sensors

A novel metal-induced lateral crystallization (MILC) technology has been applied to the formation of improved polycrystalline silicon (poly-Si) piezo-resistors, Nickel has been used for the MILC of amorphous silicon formed by low-pressure chemical vapor deposition. Independent of the physical layout of the resistors, the MILC poly-Si is found to consist of elongated grains with grain lengths comparable to the physical lengths of the resistors. Surface micro-machined micro-channels with integrated pressure sensors using both MILC and conventional low-pressure chemical vapor deposited (LPCVD) poly-Si piezo-resistors have been fabricated and characterized. Compared to the sensors with the LPCVD piezo-resistors, those with the MILC piezo-resistors show 40\% higher pressure sensitivity as well as lower temperature-induced drift in both the zero-pressure offset and the pressure sensitivity. Stability in terms of small temporal drift in the zero point offset has been obtained for the MILC pressure sensors. (C) 2000 Elsevier Science B.V. All rights reserved