| 摘要 |
PURPOSE:To form, on a substrate, a P-type layer and N-type layer well controlled in terms of thickness and concentration by a method wherein an N-type diffusion layer is formed on a P-type epitaxial layer and, simultaneously, a conductive layer is formed through the intermediary of an insulating film for the construction of a trench capacitor. CONSTITUTION:A trench is provided in a P-type Si substrate by RIE and, next, a P-type epitaxial layer 2 doped with an impurity of 5X10<16>/cm<3> boron is formed by selective epitaxy. On the P-type epitaxial layer 2, an N-type diffusion layer 3 doped with an impurity of 10<21>/cm<3> phosphorus is formed with a junction depth xj of 0.2mums. On it, an oxide film 4 is grown by thermal diffusion, and then a polycrystalline silicon layer 5 is grown by LPCVD. Phosphorus is diffused into the polycrystalline silicon layer 5 for the construction of an electrode, and then the remaining vacancy is filled with a polycrystalline silicon filler 6 for the completion of a trench capacitor. |
