Abstract: In one embodiment, a high voltage element is formed overlying a doped semiconductor region that can be depleted during the operation of the high voltage element includes a conductor overlying a space in a resistor.

Abstract: In one embodiment, a high voltage element is formed overlying a doped semiconductor region that can be depleted during the operation of the high voltage element includes a conductor overlying a space in a resistor.

Abstract: A method of manufacturing a semiconductor device having an improved ohmic contact system to epitaxially grown, low bandgap compound semiconductors. In an exemplary embodiment, the improved ohmic contact system comprises a thin reactive layer of nickel deposited on a portion of an epitaxially grown N+ doped InGaAs emitter cap layer. The improved ohmic contact system further comprises a thick refractory layer of titanium or other suitable material deposited on the thin reactive layer. Both the reactive layer and the refractory layer are substantially free of gold and other low resistivity, high conductivity metal overlayers.

Abstract: According to one exemplary embodiment, a heterojunction bipolar transistor comprises an emitter. The heterojunction bipolar transistor further comprises a first emitter cap comprising a first high-doped layer, a low-doped layer, and a second high-doped layer, where the first high-doped layer is situated on the emitter, the low-doped layer is situated on the first high-doped layer, and the second high-doped layer is situated on the low-doped layer. The first high-doped layer, the low-doped layer, and the second high-doped layer form an emitter ballast resistor. According to this exemplary embodiment, the low-doped layer has a thickness and a dopant concentration level such that the resistance of the low-doped layer is substantially independent of the dopant concentration level, but corresponds to the thickness of the low-doped layer.

Abstract: According to one disclosed embodiment, a heavily doped subcollector is formed. Subsequently, a collector is fabricated over the heavily-doped subcollectoi, wherein the collector comprises a medium-doped collector layer adjacent to the subcollector and a low-doped collector layer over the medium-doped collector layer. Both the medium-doped collector layer and the low-doped collector layer can comprise gallium-arsenide doped with silicon at between approximately 5×1016 cm−3 and approximately 1×1018 cm−3, and at between approximately 1×1016 cm−3 and approximately 3×1016 cm−3, respectively. Thereafter, a base is grown over the collector, and an emitter is deposited over the base. The collector of the HBT prevents the depletion region from reaching the subcollector without unduly impeding the expansion of the depletion region. As a result, filamentation in the subcollector is prevented, but the HBT's performance remains optimal.

Abstract: According to one embodiment, an NiV adhesion layer is deposited over the backside surface of a semiconductor substrate. The semiconductor substrate might comprise a group III-V compound semiconductor. The NiV adhesion layer can be deposited over the backside surface of the semiconductor substrate in, for example, a magnetron deposition system. In certain embodiments, the backside surface of the semiconductor surface may be cleaned to remove oxides from the surface prior to deposition of the NiV adhesion layer. After the NiV adhesion layer has been deposited, a gold seed layer is deposited over the NiV adhesion layer. Following deposition of the gold seed layer, a second gold layer is electroplated, or otherwise deposited, over the gold seed layer. In one embodiment, the invention is a structure fabricated according to the process steps described above.

Abstract: According to one embodiment, an NiV adhesion layer is deposited over the backside surface of a semiconductor substrate. The semiconductor substrate might comprise a group III-V compound semiconductor. The NiV adhesion layer can be deposited over the backside surface of the semiconductor substrate in, for example, a magnetron deposition system. In certain embodiments, the backside surface of the semiconductor surface may be cleaned to remove oxides from the surface prior to deposition of the NiV adhesion layer. After the NiV adhesion layer has been deposited, a gold seed layer is deposited over the NiV adhesion layer. Following deposition of the gold seed layer, a second gold layer is electroplated, or otherwise deposited, over the gold seed layer. In one embodiment, the invention is a structure fabricated according to the process steps described above.

Abstract: A method of manufacturing a semiconductor device having an improved ohmic contact system. The improved ohmic contact system comprises a thin reactive layer of platinum deposited on a portion of the base layer. The improved ohmic contact system further comprises a thick refractory layer of titanium or other suitable material deposited on the thin reactive layer. Both the reactive layer and the refractory layer are substantially free of gold. The improved ohmic contact system and method for forming the same eliminate base contact punchthrough on high performance semiconductor devices, such as heterojunction bipolar transistors, minimize raw material costs, and decrease manufacturing costs.

Abstract: According to one disclosed embodiment, a heavily doped subcollector is formed. Subsequently, a collector is fabricated over the heavily-doped subcollector, wherein the collector comprises a medium-doped collector layer adjacent to the subcollector and a low-doped collector layer over the medium-doped collector layer. Both the medium-doped collector layer and the low-doped collector layer can comprise gallium-arsenide doped with silicon at between approximately 5×1016 cm−3 and approximately 1×1018 cm−3, and at between approximately 1×1016 cm−3 and approximately 3×1016 cm−3, respectively. Thereafter, a base is grown over the collector, and an emitter is deposited over the base. The collector of the HBT prevents the depletion region from reaching the subcollector without unduly impeding the expansion of the depletion region. As a result, filamentation in the subcollector is prevented, but the HBT's performance remains optimal.

Abstract: A method of defining a line width includes forming a spacer (45) over a layer (42) and using the spacer (45) as an etch mask (57) while etching the layer (42). In this manner, a width (47) of the spacer (45) is used to define a width or line width (47) for the layer (42). Another method of using a spacer to define a line width includes forming a spacer (14) over a substrate (11), depositing a layer (15) over the substrate (11) and the spacer (14), planarizing the layer (15) to expose the spacer (14), and removing the spacer (14) to form an opening (19) over the substrate (11), wherein the opening (19) has a width or line width (17) of the spacer (14).