| 摘要 |
PURPOSE:To obtain a bipolar type element simply by using a polycrystalline Si film containing an impurity as a foundation layer for an emitter electrode as a mask for forming an external base, forming the extenal base in a self-alignment manner and employing the Si film as a diffusion source for an emitter. CONSTITUTION:An N<+> type buried layer 4 is diffused and formed to a P type Si substrate 1, an N type layer 2 as a collector is grown on the layer 4 in an epitaxial manner, and the layer 2 is divided into a base forming region 2a and a collector extracting region 2b by three dielectric layers 3 reaching to the layer 4. The regions 2a and 2b are coated with thin SiO2 films 5, and B and P ions are each implanted to several region to form a P type base region 6 in the region 2a and an N<+> type extracting region 7 in the region 2b. An emitter diffusion hole 8 is bored to the film 5, a polycrystalline Si film 9 containing As is deposited on the whole surface including the hole 8, and As is diffused through heat treatment to form an N<+> type emitter region 10 in the region 6. The film 9 is left only on the region 10, and B ions are implanted while using the film 9 as a mask to form a P type external base region 11 under the region 6. |
