| 摘要 |
PURPOSE:To obtain the titled device of the junction capcacitance per unit area by a method wherein an n<+> type buried region is diffusion-formed in the surface layer part of a p<-> type Si substrate, an n type layer epitaxially grown over the entire surface including the region, and the surface of the buried region being then exposed by boring a recess in the epitaxial layer, where a p type region and n<+> type region are diffusion- formed, and a negative voltage and a positive voltage are inpressed on these regions, respectively. CONSTITUTION:The n<+> type buried region 8 is diffusion-formed in the surface layer part of the p type Si substrate 1, the n type layer 2 being epitaxially grown over the entire surface including the region, and at the same time the upper part of the region 8 then being advanced into the layer 2 by the swelling of the volume of the region 8. Next, the surface of the region 8 is exposed by etching the layer 2 with SiO2 films 9 and 10 formed by methods of oxidation and CVD as a mask, and then the layers 2 is isolated in island form by means of a p type region 14 reaching the substrate 1, while containing the region 8. thereafter, the p type region 13 and the n<+> type region 15 are provided in the region 8, the films 9 and 10 are removed, windows are opened after adhesion of an SiO2 film 16 over the entire surface, and electrodes A1 ans B1 for impressing negative and positive voltages are mounted on the regions 13 and 15, respectively. |
