Fabricating silicon mesh bolometers for BAM

• Main Author: Chen, Karen
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/10248

Silicon membranes have been fabricated and etched into mesh structures using both wet and Cl₂ plasma etching. The most repeatable process involoved wet etching triple bonded wafers with a buried oxide layer. A recipe to build Si meshes, with a grid spacing of 375 μm and leg cross-sections of 5 μm by 30 μm, from 5 μm thick membranes is described. The meshes are supported by 4 legs that are each 30 μm wide and 1 mm long. Also, the resistivity of thin gold films was measured for temperatures ranging from 4.2 K to 300 K. It was found that the ideal thickness, that leads to a sheet resistance of at 300 mK for of 5μm by 385μm gold lines, was 150 Å. A bolometer building process that incorporates the gold evaporations with the mesh building procedure is given, although preliminary attempts to produce bolometers have been unsuccessful.