Abstract: A fabrication process of a novel SOI material with a non-planar buried oxide layer was developed using a series of key processes.A high quality non-planar buried oxide film was made by dry etching,thermal growth,and chemical-vapor deposition.A poly-silicon buffer layer for bonding was deposited by CVD and was planarized by photoresist block masking and chemical mechanical polishing.The active and substrate wafers were bonded by vacuum contacting at room temperature,with pre-bonding at a moderate temperature and final firming bonding at a high temperature.Based on these key processes,a novel SOI material with a non-planar buried oxide layer was fabricated.The structure includes an active layer with a thickness of 21μm,a buried oxide with a thickness of 0.943μm,and self-aligned top and bottom trenches with thicknesses of about 0.9μm.The measurements indicate a high quality bonded interface with a large combining intensity and excellent electrical performance with a high breakdown electric field.

Key words: SOI, planarization, bonding, buried oxide layer