FIELD EFFET CONTROL TYPE BIPOLAR POWER SEMICONDUCTOR DEVICE AND ITS MANUFACTURE

摘要

PURPOSE: To increase a latchup current of a bipolar power semiconductor element until it is largely immune to its latchup, by performing the conductive coupling of its individual cathode contact to its accessory n-region via the conductive layer extended between them on the surface of its substrate. CONSTITUTION: In a bipolar power semiconductor element, the creations of conductive layers 12, 13 are started from the stage wherein the doping of the inside of a substrate 1 exists and a gate electrode 7 is formed to cover its surface with a gate insulator 6. While an anisotropic etching is applied to the gate insulator 6, the gate insulator 6 present in the peripheral region of the electrode 7 is left and the one present under the electrode 7 is also conversed due to the ununiformity of the edge thicknesses of the gate electrode 7. Then, on the whole surface of this structure, metals are welded or deposited to form metal silicides with silicon. Adjusting a tempering temperature so that the metal silicides are formed on both the substrate 1 and the gate electrode 7 made of polymerized silicon but not formed in the peripheral region of the SiO2 gate insulator 6 of the gate electrode 7, remaining non- reaction metals are removed therefrom by etching and an insulated SiO2 layer is welded thereon to metallize the cathode of the element thereafter by digging a contact hole through the insulated SiO2 layer. As a result, an n-region length X3 of the element can be shortened to make the latchup of the element remarkably preventable.