Uncooled microbolometers with hydrogenated amorphous germanium-silicon films: Different device configurations and improvements on the thermosensing films

摘要

We report our main results on the development of un-cooled microbolometers based on hydrogenated amorphous Germanium-Silicon (a-Ge_xSi_y:H) thermo-sensing films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD). Our research has been conducted to improve both, the structure of the devices (pixels) and the performance characteristics of the amorphous Germanium-Silicon thermosensing films. Our motivation is to produce microbolometers with much better performance characteristics (larger thermal coefficient of resistance, larger conductivity and better stability) than those available in commercial microbolometer arrays, based on boron doped hydrogenated amorphous silicon (a-Si:H,B). As part of our latest research, we also report the study of what we believe is the next generation of thermosensing films based on Silicon and Geranium amorphous films with embedded nanocrystals in the amorphous matrix (polymorphous films). Those materials have several advantages over amorphous, as a lower defect density, better stability and better transport properties.