Linear arrays of uncoolded poly SiGe microbolometers for IR detection

摘要

In this work we demonstrate the advantages of using polycrystalline silicon germanium (poly SiGe) as a structural material for surface micromachined devices, and more specifically uncooled Infra-Red (IR) microbolometers. The low stress and the low thermal conductivity of poly SiGe enable the realization of IR microbolometers having an effective detectivity above 2 $MUL 10$+9$/ cm.Hz$+$HLF$//W. Currently, linear arrays of optimized devices included in an on-chip vacuum package are developed. The vapor HF sacrificial etching technique is used to release extremely thin microbolometers with high yield. Combined with the practical advantage of an uncooled system, a low-cost yet sensitive sensor system is the result. Possible applications include space based pushbroom earth sensing, spectral environmental monitoring and process control.