| 摘要 |
PURPOSE:To improve electric characteristics and to contract the area of an element by forming a recess by selective etching, the forming a low resistance diffused layer on the entire recess, burying the recess to form a semiconductor layer, and flattening the surface of a semiconductor substrate. CONSTITUTION:A silicon oxide film 2 is formed on a P type silicon substrate 1, selectively etched, and the substrate 1 is etched with the remaining film 2 as a mask. An N<+> type collector buried layer 3 is formed, the film 2 and a glass layer 4 containing As or Sb are removed by etching, and an N type epitaxial layer 5 is formed on the entire surface. After the layer 5 is formed, a resist 6 is spin coated, dried and flattened. The resist 6 and the silicons are etched to the specific surfaces, the substrate is flattened, oxided in oxidative atmosphere to form a thermally oxidized silicon film 7, and a P type diffused layer 8 and a P type diffused layer 9 are formed with the film 7 as a mask. Thus, a collector buried diffused layer is formed in high density, a collector resistance is reduced to decrease a saturated voltage. |
