METHOD FOR MANUFACTURING DUAL SILICON SUBSTRATE

摘要

PURPOSE: A method for manufacturing a dual silicon substrate is provided to effectively eliminate a dishing phenomenon occurring on the surface of a semiconductor substrate, and to improve a characteristic of a device by increasing thickness uniformity of the semiconductor substrate. CONSTITUTION: A trench isolation layer is formed on a semiconductor substrate. A buried oxide layer(13) is formed on the semiconductor substrate having the isolation layer. A base substrate(14) is bonded to the buried oxide layer. A part of the semiconductor substrate is polished to form a semiconductor layer of which the center portion is dished, by the first chemical mechanical polishing(CMP) process using the isolation layer as a polishing stop layer. The isolation layer is etched to a predetermined thickness. A photoresist layer is deposited on the etched isolation layer and the polished semiconductor layer. The photoresist layer and the semiconductor layer are polished to form a semiconductor layer of a uniform thickness by the second CMP process using the etched isolation layer as a polishing stop layer.