| 摘要 |
PROBLEM TO BE SOLVED: To provide superior transistor characteristics by forming an STI structure having a liner silicon nitride film uniformly. SOLUTION: A semiconductor substrate 101 is etched on which a first silicon oxide film 102 and a first silicon nitride film 103 are deposited sequentially, and an element separation trench 105 is formed. A second silicon oxide film 106 is formed on all the face including trench inner wall, and a second silicon nitride film 107 is formed for covering the second silicon oxide film. A third silicon oxide film 103 is formed for covering the second silicon nitride film isotropically, and a fourth silicon oxide film 109 is embedded inside the trench. Part of the third silicon oxide film and the fourth silicon oxide film in the trench is removed by etching, and an exposed part of the second silicon nitride film is removed by etching. A fifth silicon oxide film 110 is deposited on all the face including the inside of the trench, and the fifth silicon oxide film and the second silicon oxide film are removed by using the first silicon nitride film as polishing stopper film, and then the first silicon nitride film is removed by etching. COPYRIGHT: (C)2008,JPO&INPIT
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