Abstract: A process for fabricating a bipolar junction transistor, featuring the use of multiple self-aligned collector regions, used to limit the width of the base region of the transistor, has been developed. The self-aligned collector regions are formed via multiple ion implantation procedures, performed through, and self-aligned to, an overlying emitter opening, in an oxide layer. The self-aligned collector regions, completely fill the space in the lighter doped collector region, located between the overlying base region, and the underlying subcollector region.

Abstract: A process for fabricating a BiCMOS device, on a semiconductor substrate, featuring PFET and NFET devices, and an NPN bipolar junction transistor, has been developed. The process features the integration, or the sharing of process steps, used for both the CMOS and bipolar devices, such as the creation of an N type buried layer, used in one region for isolation of PFET devices, and used in a second region, of the semiconductor substrate, as a subcollector region, for the bipolar device. Features of the BiCMOS process include the formation of N well, and P well regions, for CMOS device, as well as the use of an epitaxial silicon layer, to allow optimum bipolar characteristics to be achieved.

Abstract: A bipolar junction transistor structure and method of forming the bipolar junction transistor structure comprising an intrinsic base surrounded by a base link and an extrinsic base surrounding the base link. An emitter is formed above the base. The extrinsic base, base link, and intrinsic base are formed using ion implantation. A single layer of doped polysilicon is used to provide the doping source for the emitter and a collector contact. Silicide contacts to the emitter, collector, or base are not required or used.

Abstract: A new method of forming simultaneously both shallow and deep trenches is described. A pad oxide layer is provided over a semiconductor substrate. A silicon nitride layer is deposited overlying the pad oxide layer. A silicon dioxide layer is deposited overlying the silicon nitride layer. A photoresist mask is formed over the silicon dioxide layer wherein the photoresist mask has a first opening having a first width and a second opening having a second width and wherein the second width is larger than the first width. Trench openings are etched through the silicon dioxide, silicon nitride, and pad oxide layers to the underlying semiconductor substrate within the first and second openings. The photoresist mask is removed.