| 摘要 |
PURPOSE:To simplify processes, by forming two p-n junctions by a single epitaxial growing process and a heat treatment process at a low temperature. CONSTITUTION:On the surface of a p type CZ silicon substrate 1 including excessively saturated oxygen atoms, an n type epitaxial layer 2 is grown to a thickness of about 5mum by an epitaxial growing method utilizing thermal deomposition of SiH4, and a first p-n junction 3 is formed. Then heat treatment of the epitaxial substrate is carried out in an N2 atmosphere at 400 deg.C for about 60hr. A second p-n junction 4 is generated in the bulk of the p type silicon substrate 1. A p type region 5 and an n type region 6 are formed. An npn structured bipolar transistor is formed. By controlling the low-temperature heat treatment hours, the width of the p type region 5 (width of a base) can be readily controlled. |
