| 摘要 |
PROBLEM TO BE SOLVED: To realize a stable hFE, by surely preventing a single crystal of polycrystalline silicon, constituting an emitter electrode in the case of heat treatment for diffusing impurities, preventing the remain of an interface oxide film and reducing emitter-electrode resistance, while controlling emitter-electrode concentration according to a design, and to improve yield and enhance reliability on an element by preventing the generation of a watermark and foreign substance in cleaning, after dry etching for forming the emitter electrode. SOLUTION: An insulating film 4 and the first polycrystalline silicon film 5 are selectively dry-etched and a connecting hole is formed, and a substrate is cleaned by using a cleaning liquid composed of ammonia, hydrogen peroxide and water.
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