基于非晶硅薄膜的微测辐射热计光学仿真和优化

Optical Optimization and Simulation of Micro-bolometers Based on α-Si:H Thin Film

基于非晶硅薄膜的非制冷微测辐射热计具有结构简单、易于大规模集成、工艺兼容以及良好探测性能等特点,在红外探测领域等受到关注。引入氮化钛薄膜作为新型红外吸收材料,通过光学导纳矩阵法,对基于非晶硅薄膜的微测辐射热计的红外吸收特性,进行了仿真和优化研究。结果表明,非晶硅微测辐射热计中,氮化钛/非晶硅复合薄膜具有良好的红外吸收性能。当非晶硅薄膜厚度为120 nm时,由氮化钛/非晶硅组成的膜系在8～14μm范围内具有96%左右的红外吸收率,其中氮化钛薄膜的最佳吸收厚度为32nm。

Uncooled micro-bolometer based on hydrogenated amorphous silicon（a-Si：H） thin film has attracted many attentions in the infrared （IR） field of civilian and military applications due to its simple cell-structure, good compatibility for large scale integration and effective detection. In this paper, we bring in titanium nitride as a novel infrared absorption material and carry out some optical simulation and optimization on the infrared absorbing performance of micro-bolometers based on a-Si：H thin film. The results show that when the a-Si：H thin film is taken as 120 nm thick, the combined thin film layer consisting of TiN and a-Si：H has a high infrared absorption as high as 96% in the wavelength from 8 ktm to 14 um, in which the best thickness of TiN thin film is 32 nm.