| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for forming an extremely thin silicon oxide film of low leak current density and high quality on a silicon substrate at a low temperature with highly controllablity of film thickness. SOLUTION: After cleaning the surface of the silicon substrate 1, the silicon substrate 1 is dipped in an HF aqueous solution of a 0.5 vol% concentration to remove impurities and natural oxide films from the surface of the silicon substrate 1. After rinsing the silicon substrate 1 with super-pure water for 5 min, the silicon substrate 1 is dipped in an azeotropic nitric acid heated at a 120.7°C azeotropic temperature, an extremely thin chemical oxide film 5 is formed on the surface of the silicon substrate 1, a metal film 6 (aluminum/silicon alloy film) is deposited, and then the silicon film 1 covered with the films 5, 6 are heated in gas containing hydrogen at 200°C for 20 min. Since heat treatment is performed in the atmosphere containing hydrogen, hydrogen reacts with boundary levels and defect levels formed in the chemical oxide film 5, so that these levels disappear. Consequently, film quality can be improved. COPYRIGHT: (C)2004,JPO
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