| 摘要 |
PURPOSE:To assure high yield and quantity by a method wherein thin oxide film is formed inside polysilicon layer and then only the upper part of thin film inside polysilicon layer is ion-implanted. CONSTITUTION:An N type epitaxial layer 22 is formed on a P type silicon substrate 21 to form an oxide film 23a and a P type impurity layer 24 by selective oxidizing process. Next thin oxide film 29 several Angstrom - several scores of Angstrom thick is formed by introducing oxidizing gas while polysilicon is being grown and then polysilicon films 27a, 27b with the oxide film 29 are formed by means of sustaining to grow silicon. Then an emitter part 25, a collector contact part 26 are ion implanted with As and only the upper part of oxide film 29 is implanted with impurity by controlling implanting energy and amount. Finally the emitter part 25 and the collector part 26 may be formed by means of diffusing as by heat treatment. |
