| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of a nodule effectively while restraining influence of auto-dope by surely removing an unnecessary oxide film alone by simple operation. SOLUTION: The degree of surface roughness of a granular porous oxide film 2b', which creeps from a circumferential side 1b of a silicon single crystal substrate 1 to a surface 1c side and attaches, is higher than that of flat oxide films 2a, 2b, which are laminated along a rear 1a of the silicon single crystal substrate 1 and have a uniform thickness. When such a granular porous oxide film 2b' comes into contact with an etchant 6, an etching amount per unit time is large since a surface area in contact with the etchant 6 is larger than that of the flat uniform oxide films 2a, 2b of the rear 1a. Therefore, the granular porous oxide film 2b' alone is removed due to the difference in etching rate. COPYRIGHT: (C)2003,JPO
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