| 摘要 |
PURPOSE:To improve integration by forming an insulator isolating region made of a groove having a depth sufficient to electrically isolate on a semiconductor substrate between adjacent other MOS type transistor pair. CONSTITUTION:MOS type transistors are formed on the counter side faces of one hole in the hole formed from the surface of a semiconductor substrate 1 toward the interior of the substrate. The two transistors both have diffused layers 4 formed in the bottom of the hole. An insulator isolating region 5 is formed on the periphery of the hole. It is so etched back that a suitable amount of a coating insulating film 2 containing impurity remains in the hole, and a thin gate insulating film is formed on the surface of the substrate 1. A gate electrode material is etched back except a suitable length in the hole, an impurity exhibiting opposite conductivity type to that of the substrate 1 is implanted to a groove opening side, then heat treated at a high temperature to form a diffused layer 4. Simultaneously, impurity is thermally diffused in the substrate 1 from the film 2 containing the impurity in the depth of the hole, thereby forming a diffused layer 4 also in the deep bottom of the hole. |
