Arrays of un-cooled micro-bolometers based on amorphous silicon-germanium thin films deposited by plasma

摘要

We report the study of a fabrication process and characterization of one (1 D) dimensional arrays of un-cooled micro-bolometers based on amorphous silicon-germanium thermo-sensing films deposited by a low frequency PECVD at low temperature and fully compatible with the IC fabrication technology. Two different thermo-sensing films have been employed in the micro-bolometer arrays, an intrinsic film a-SixGey:H and a boron alloy a-SixGeyBz:H. The 1D array is composed of 32 elements. The active area of the cells in the array is A(b) = 70 x 66 mu m(2) and the area of the array including interconnection lines and pads is A(A) = 1.6 x 3.1 mm(2). The temperature dependence of conductivity sigma(T), current-voltage characteristics I(U) and spectral noise density have been measured in the micro-bolometer arrays with both types of thermo-sensing films in order to characterize and compare their performance characteristics, such as responsivity R and detectivity D*.