The Microassembly Technique for a 3D Single Crystalline Silicon Structure Using a Polyimide/Chromium Cantilever

The microassembly technique on the wafer is key technology to realize multi-axis sensors (e. g. magnetometer) or three-dimensional micro systems (e. g. an optical system). We have investigated the bending of a polyimide/chromium cantilever to lift a silicon island (400×300×10μm3 and 1000×1000×240μm3) on the wafer at an angle of 90°, the planarization of a diced silicon sidewall and the bonding of a silicon island to the planarized silicon sidewall with polyimide interlayer. With this microassembly technique, the three-dimensional single crystalline silicon structures have been fabricated.