Semiconductor embedded layer technology utilizing selective epitaxial growth methods

摘要

A permeable base transistor (30) including a metal base layer (34) embedded in a semiconductor crystal (32) to separate collector (38) and emitter (40) regions and form a Schottky barrier with each is disclosed. The metal base layer has at least one opening (37) through which the crystal semiconductor (32) joins the collector (38) and emitter (40) regions. Ohmic contacts (42,44) are made to the emitter (38) and collector (40) regions. The width of all openings (37) in the base layer (34) is of the order of the zero bias depletion width corresponding to the carrier concentration in the opening. The thickness of the metal layer (34) is in the order of 10% of this zero bias depletion width. As a result, a potential barrier in each opening limits current flow over the lower portion of the bias range. With increasing forward base bias the potential in the openings, which is lower than along the metal of the base layer (34), is lowered sufficiently to permit substantial increase in the barrier limited current flow from the collector (38) to emitter (40). A method of fabricating this transistor as well as methods for forming integrated circuit structures are also disclosed. Metal and other layers may be selectively embedded in semiconductor crystal. Embedded metal layers may serve as interconnections between devices. Devices may be in a stacked configuration.