| 摘要 |
PURPOSE:To microminiaturize and accelerate an IIL by contracting the pattern area of an upper base leading region. CONSTITUTION:A P-type impurity such as boron ions are implanted to a region to become a lower base leading region 19a to be superposed on the first doped layer 21 to form the second doped layer 22. A P-type impurity is selectively ion implanted to a region to become a buried base region 16 to be superposed with the layer 21 to form the third doped layer 23 of lower density than the layer 22. Then, an N<-> type epitaxial layer 12 is formed on the entire substrate 11. A separating region 14 is selectively diffused, the first-third doped layers 21-23 doped previously by heating treating at this time are diffused elevationally to simultaneously form a buried layer 13, a lower base leading region 19a and a buried base region 16. A P-type injector region 17 and a P-type upper base leading region 19b are selectively diffused, an N<+> type collector contacting region 18 and an N<+> type emitter contacting region 20 are further selectively diffused, and electrodes are eventually arranged on the regions. |
