Northrop Grumman Systems Corporation

Donald James Sawdai

Augusto L Gutierrez-Aitken

Vincent Gambin

Vesna Radisic

Tsung-Pei Chin

Gregory Scott Leslie

Kwok K Loi

A unipolar diode with low turn-on voltage includes a subcathode semiconductor layer, a low-doped, wide bandgap cathode semiconductor layer, and a high-doped, narrow bandgap anode semiconductor layer. A junction between the cathode layer and the anode layer creates an electron barrier in the conduction band, with the barrier configured to produce a low turn-on voltage for the diode. A unipolar diode with low turn-on voltage includes an nsubcathode semiconductor layer, a low-doped, wide bandgap cathode semiconductor layer, and an nnarrow bandgap anode semiconductor layer. Again, a junction between the cathode layer and the anode layer creates an electron barrier in the conduction band, with the barrier configured to produce a low turn-on voltage for the diode.

Unipolar diode with low turn-on voltage

Formation of a regrowth layer of a Group III&#x2013;V semiconductor material is facilitated by prior formation of an intermediate layer, selected primarily for its smooth morphology properties. The intermediate layer is formed over an underlying substrate and over a dielectric layer formed over portions of the substrate. The intermediate layer maintains the monocrystalline properties of the underlying substrate in regions other than those covered by the dielectric layer, and improves the electrical and morphology properties of the regrowth layer formed over the intermediate layer.

Method for growth of group III-V semiconductor material on a dielectric

A double heterojunction bipolar transistor structure having desirable properties of a low base-emitter turn-on voltage and no electron blocking discontinuities in the base-collector junction. These properties are achieved by selecting base, emitter and collector materials to provide a bandgap profile that exhibits abrupt transitions at the heterojunctions, such that both abrupt transitions are due to transitions in the valence band edge of the bandgap, but not in the conductive band edge of the bandgap.

Low turn-on voltage, non-electron blocking double HBT structure

A heterojunction bipolar transistor (HBT) device structure is provided which facilitates the reduction of the base-collector capacitance and a method for making the same. The base-collector capacitance is decreased by fabricating a base micro-bridge connecting a base contact to a base mesa on the HBT. The base micro-bridge is oriented along about one of 001, 010, 00{overscore (1)}, and 0{overscore (1)}0 direction to a major flat of the wafer. The HBT device employs a phosphorous based collector material. During removal of the phosphorous based collector material, the base layer is undercut forming the micro-bridge, successfully removing the collector and sub-collector material below the bridge due to the orientation of the micro-bridge. The removal of collector and sub-collector material reduces the base-collector junction area, and therefore reduce the base-collector junction capacitance.

Double HBT base metal micro-bridge

A preferred embodiment of the present invention provides a Schottky diode formed from a conductive anode contact, a semiconductor junction layer supporting the conductive contact and a base layer ring formed around at least a portion of the conductive anode contact. In particular, the base layer ring has material removed to form layer material gap (e.g., a vacuum gap) adjacent to the conductive anode contact. A dielectric layer is also provided to form one boundary of the base layer material gap.

Low leakage schottky diode

A preferred embodiment of the present invention provides a Schottky diode ( ) formed from a conductive anode contact ( ), a semiconductor junction layer ( ) supporting the conductive contact ( ) and a base layer ring ( ) formed around at least a portion of the conductive anode contact ( ). In particular, the base layer ring ( ) has material removed to form a base layer material gap ( ) (e.g., a vacuum gap) adjacent to the conductive anode contact ( ). A dielectric layer ( ) is also provided to form one boundary of the base layer material gap ( ).

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Redondo Beach, CA, United States of America

Donald James Sawdai