SIDEWALL JUNCTION FOR BIPOLAR SEMICONDUCTOR DEVICES

摘要

A bipolar semiconductor device (450) having sidewall junction structures is comprised of a wafer substrate (460) having substantially vertical trenches (452, 454) formed therein and defined by a plurality of sidewalls. Through the sidewalls, dopants of preselected conductivity are introduced into the substrate to form sidewall junctions (462, 464). Additionally, the vertical trenches are used to contain a corresponding metal electrode (456, 468) (e.g., emitter, collector cathode, or anode) of the device, such electrodes being a function of the type of semiconductor junction device formed. According to the present invention, the current flow is parallel to the wafer surface (458), as with a typical lateral device, but the current flow is also perpendicular to the surfaces (i.e., sidewalls) through which the dopants are introduced, which is typical of a vertical device. Such a sidewall junction structure results in better utilization of the area volume of the device. Semiconductor junction devices which may be formed using the present invention include transitors, thyristors, and rectifiers.