| 摘要 |
PURPOSE:To increase a current amplification factor, and to manufacture a semiconductor device stably with high yield by forming a buried second conduction type high-concentration region and selectively forming a first conduction type buried region, which is not in contact with others, on the semiconductor layer side in the high-concentration region. CONSTITUTION:An N<+> type buried region 2 is formed to a P type semiconductor substrate 1, and a P type buried layer 3 is formed. An N type epitaxial layer 4 is formed on the whole surface. A P type impurity is diffused to the layer 4 to form P type regions 5, 6. The P type region 5 functions as an I<2>L injector and the P type region 6 as an I<2>L base. N<+> type regions 7 are formed in the P type region 6. The N<+> type regions 7 function as I<2>L collectors. Holes injected to the emitter 4 from the P type base 6 are captured by the P type buried region 3, potential rises with the increase of the holes, and finally holes begin to be injected to the emitter region 4. Accordingly, hole concentration on the emitter side in the vicinity of a base-emitter junction increases, an injection from the base is Inhibited, and injection efficiency is improved. Most of a current amplification factor are determined by the injection efficiency. |
