Design and fabrication of low-deformation micro-bolometers for THz detectors

Control of the residual film stress to the desired levels is critical for the design and fabrication of high-quality micro-bolometers for terahertz (THz) detectors. In this work, a stress equivalent method was employed to investigate the deformations of the suspended mull-layer micro-bolometers. According to the orthogonal calculation results obtained by a design of experiment (DOE) method, the optimal residual stress for each layer was simulated, by which high-quality micro-bolometers with low deformation were designed. Furthermore, 384 x 288 THz focal plane arrays constructed by the as-designed micro-bolometers were successfully fabricated. Particularly, the as-fabricated micro-bolometers have uniform morphologies, smooth surfaces, low deformations of 0.063 mu m, all of which are accordance with the simulated results and suggest suitable applications of the designed micro-bolometers in THz detecting.