| 摘要 |
PURPOSE:To produce a semiconductor device with LDD structure easily subject to excellent controllability by means of ion implanting process utilizing an insulating film both serviceable as interlayer insulating film as a mask. CONSTITUTION:The surface of substrate 1 is firstly ion-implanted with boron thinly at low concentration to form a gate electrode 5 and an oxide film 11 with thickness t as an interlayer insulating film from upper wiring. Then the second ion-implanting process is performed with high energy to increase the concentration of impurity on the substrate. A channel region is formed due to impurity not reaching the surface of substrate since the substrate is coated with gate electrode 5 added to the oxide film 11 immediately below the gate electrode 5 of substrate 1. The oxide film 11 is deposited with thickness almost 2Xt around the gate electrode 5 not to be implanted with impurity forming into a region 7' with thin junction depth. On the other hand, the impurity implanted into source, drain regions coated with the oxide film 11 with thickness of t is diffused by heat treatment to form a LDD type MOSFET formed of composite source, drain comprising a region 10 with remarkable surface concentration and junction depth. |
