THYRISTOR HAVING AT LEAST FOUR SEMICONDUCTIVE REGIONS AND METHOD OF MAKING THE SAME

摘要

A thyristor having a base region shorted to an associated emitter region on one of the principal faces of the thyristor wafer, wherein there is a net impurity center concentration equal to at least 1018 impurity centers per cubic centimeter at the surface of the base region in contact with the shorting electrode, wherein there is a continual decrease of the net impurity center concentration in the base region from its value at the shorting electrode at least over the distance from the shorting electrode to the side of the emitter region farthest from the shorting electrode, and wherein there is an ohmic contact of very small contact resistance between the shorting electrode and the base region.