METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce the parasitic capacitance of a transistor having a gate all around (GAA) structure.SOLUTION: A channel region 11 made of a silicon film is formed on a silicon oxide film 3 arranged on a silicon substrate 2. Phosphorus is injected into the silicon oxide film 3 under the channel region 11 and on a side thereof so as to form a modified part having a higher etching rate than that of a region into which phosphorus is not injected. Phosphorus is injected into the silicon oxide film 3 under the channel region 11 also through the channel region 11. Then, a cavity is formed by removing the modified part 21 by isotropic wet etching. A gate electrode is deposited inside and above the cavity.