An infrared sensing material using a large-grain polysilicon film

Abstract

We first report the feasibility of using large-grain polycrystalline silicon films as a sensing material for infrared bolometers. To increase the average grain size of polysilicon films, we used seed selection through ion channeling, which resulted in a large grain size of 1670 A. The temperature coefficient of resistance (TCR) at 20 degrees C and the grain boundary defect density of the film were as high as -2.46%/K for a resistivity of 30 Q cm and about 1.752 x 10(12)/cm(2), respectively. From the measurement of noise characteristics of the film, the value of k, 1/f noise parameter, was calculated to be 1.35 x 10(-9). As a result, the estimated detectivity was found to approach 5.6 x 10(8) cm Hz (1/2)/W.