Fabrication of a micro cryogenic cooler using MEMS-technology

This paper describes the design and production process of a variety of reliable micro cryogenic coolers. The different cold stages are based on an optimized design found during a study which was done to maximize the cold-stage effectiveness. Typical cold-stage dimensions are 30 × 2 × 0.5 mm with an expected net cooling power varying from 10 mW to 20 mW at a tip temperature of 96 K. A cold stage consists of a stack of three fusion bonded D263T glass wafers. The production process has 7 lithography steps and roughly 100 process steps. In order to determine the maximum bend, shear and bond stresses inside a 175 µm thick D263T glass wafer, several pressure tests were performed.