Abstract: Narrow and wide, planar field isolation region (72, 74, 152, 172, 182) is formed by forming trenches (52, 54) within a substrate (10). For wide, planar field isolation regions (72, 152, 172, 182), the trenches (52) define at least one mesa (76, 150, 170, 180) within the field isolation region (72, 152, 172, 182). The trenches (52, 54) are filled with a material (62) that is polished or etched to form the planar field isolation region (72, 74, 152, 172, 182) where the wide, planar field isolation regions (72, 152, 172, 182) include the mesa(s) (76, 150, 170, 180). Etching can be used or by polishing with minimal, if any, dishing occurs because the widths of the trenches (52, 54) are kept relatively narrow (usually no more than five microns wide). Mesas (180) within a wide, planar field isolation region (182) can form linguistic characters to better identify the part number or mask set of the device.

Abstract: A substantially concentric lateral bipolar transistor having a base region that is disposed about a periphery of an emitter region, and a collector region that is disposed about a periphery of the base region to form the concentric lateral bipolar transistor of the invention. A gate overlies the substrate and at least a portion of the base region. At least one electrical contact is formed connecting the base and the gate, although a plurality of contacts may be formed. A further bipolar transistor is formed according to the following method of the invention. A base region is formed in a substrate and a gate region is formed overlying at least a portion of the base region. Emitter and collector terminals are formed on opposed sides of the base region. The gate is used as a mask during first and second ion implants.

Abstract: In a semiconductor device manufacturing method for forming first and second bipolar transistors on a semiconductor substrate 1, a link base layer 5 for connecting a graft base layer (graft base layer 8) of the first bipolar transistor and an intrinsic base layer 12 to each other, and at least a part of a base layer 6 of the second bipolar transistor are formed simultaneously with each other, and then the link base layer 5 in a region where the intrinsic base layer 12 will be formed is removed by an etching treatment, and then by a selective epitaxial growth method, the intrinsic base layer 12 is formed in the region where the link base layer 5 is removed.

Abstract: A bonded, SOI wafer which has stepped isolation trenches and sublayer interconnections first formed in a bulk silicon wafer. After these process steps are complete, a thin polysilicon layer is formed on the planarized upper surface of the bulk silicon wafer. This thin polysilicon layer is then bound to an oxide layer on the surface of a separate wafer to form a bonded silicon-on-oxide structure. The entire assembly is, in effect inverted, and what had been the lower surface of the bulk silicon wafer, is removed to the bottom of the deepest trench step. In this bonded SOI structure, regions between the trenches are deep and suitable for bipolar device fabrication, while the trench steps form shallow regions suitable for fabrication of CMOS devices.

Abstract: n type epitaxial layers are formed on the main surface of a p type semiconductor substrate. A field oxide film is selectively formed in the surface of n type epitaxial layers. An n type diffusion region is formed in n type epitaxial layers positioned directly under field oxide film. A base region and a collector region are respectively formed in the surface of n type epitaxial layer positioned between field oxide films. As a result, a semiconductor device having an IIL circuit is obtained which can suppress the parasitic bipolar operation between base regions, reduce the junction capacitance between the base region and the emitter region and which can be reduced in size.

Abstract: A heterojunction type of compound semiconductor integrated circuit in which a PNP transistor has an N type substrate made of a first compound semiconductor for mounting the PNP transistor and for insulating positive holes transmitted in the PNP transistor, a P type second compound semiconductor limitedly arranged on a part of the substrate for functioning as an emitter of the PNP transistor, an N type third compound semiconductor arranged on both the second compound semiconductor and the substrate for functioning as a base of the PNP transistor, electrons being applied from the substrate to the third compound semiconductor, a P type fourth compound semiconductor limitedly arranged on a part of the N type third compound semiconductor, a P.sup.