Abstract: The present disclosure provides a method of fabricating a semiconductor device. The method includes forming a buffer layer over a substrate, the buffer layer containing a first compound semiconductor that includes elements from one of: III-V families of a periodic table; and II-VI families of the periodic table. The method includes forming a channel layer over the buffer layer. The channel layer contains a second compound semiconductor that includes elements from the III-V families of the periodic table. The method includes forming a gate over the channel layer. The method includes depositing impurities on regions of the channel layer on either side of the gate. The method includes performing an annealing process to activate the impurities in the channel layer.

Abstract: Embodiments include semiconductor devices with low leakage Schottky contacts. An embodiment is formed by providing a partially completed semiconductor device including a substrate, a semiconductor on the substrate, and a passivation layer on the semiconductor, and using a first mask, locally etching the passivation layer to expose a portion of the semiconductor. Without removing the first mask, a Schottky contact is formed of a first material on the exposed portion of the semiconductor, and the first mask is removed. Using a further mask, a step-gate conductor of a second material electrically coupled to the Schottky contact is formed overlying parts of the passivation layer adjacent to the Schottky contact. By minimizing the process steps between opening the Schottky contact window in the passivation layer and forming the Schottky contact material in this window, the gate leakage of a resulting field effect device having a Schottky gate may be substantially reduced.

Abstract: Methods and apparatus are described for semiconductor devices. A method comprises providing a partially completed semiconductor device including a substrate, a semiconductor on the substrate, and a passivation layer on the semiconductor, and using a first mask, locally etching the passivation layer to expose a portion of the semiconductor, and without removing the first mask, forming a Schottky contact of a first material on the exposed portion of the semiconductor, then removing the first mask, and using a further mask, forming a step-gate conductor of a second material electrically coupled to the Schottky contact and overlying parts of the passivation layer adjacent to the Schottky contact. By minimizing the process steps between opening the Schottky contact window in the passivation layer and forming the Schottky contact material in this window, the gate leakage of a resulting field effect device having a Schottky gate may be substantially reduced.

Abstract: A semiconductor device comprising a honeycomb heteroepitaxy and method for making same are described. One embodiment is a method comprising defining a mask on a silicon substrate, the mask comprising a plurality of nano-size openings therethrough; subsequent to the defining, creating essentially defect-free non-silicon semiconductor nano-islands on portions of a surface of the silicon substrate exposed through the mask openings; subsequent to the creating, depositing high-k gate dielectric is deposited on the nano-islands; and subsequent to the deposition, constructing transistors on the nano-islands.

Abstract: A thin body MOSFET with conducting surface channel extensions and gate-controlled channel sidewalls is described. One embodiment is a MOSFET comprising a semiconductor substrate; a channel layer disposed on a top surface of the substrate; a gate dielectric layer interposed between a gate electrode and the channel layer; and dielectric extension layers disposed on top of the channel layer and interposed between the gate electrode and Ohmic contacts. The gate dielectric layer comprises a first material, the first material forming an interface of low defectivity with the channel layer. In contrast, the dielectric extensions comprise a second material different than the first material, the second material forming a conducting surface channel with the channel layer.

Abstract: A semiconductor fabrication process includes forming a gate dielectric layer (120) overlying a substrate (101) that includes a III-V semiconductor compound. The gate dielectric layer is patterned to produce a gate dielectric structure (121) that has a substantially vertical sidewall (127), e.g., a slope of approximately 45° to 90°. A metal contact structure (130) is formed overlying the wafer substrate. The contact structure is laterally displaced from the gate dielectric structure sufficiently to define a gap (133) between the two. The wafer (100) is heat treated, which causes migration of at least one of the metal elements to form an alloy region (137) in the underlying wafer substrate. The alloy region underlies the contact structure and extends across all or a portion of the wafer substrate underlying the gap. An insulative or dielectric capping layer (140,150) is then formed overlying the wafer and covering the portion of the substrate exposed by the gap.

Abstract: A method of forming a semiconductor structure includes forming a channel layer; forming a superlattice barrier layer overlying the channel layer, and forming a gate dielectric overlying the superlattice barrier layer. The superlattice barrier layer includes alternating first and second layers of barrier material. In addition, the superlattice barrier layer is configured for increasing a transconductance of the semiconductor device by at least a factor of three over a semiconductor device absent such superlattice barrier layer.

Abstract: A method of forming a portion (10) of a compound semiconductor MOSFET structure comprises forming a compound semiconductor layer structure (14) and an oxide layer (20) overlying the same. Forming the compound semiconductor structure (14) includes forming at least one channel material (16) and a group-III rich surface termination layer (18) overlying the at least one channel material. Forming the oxide layer (20) includes forming the oxide layer to overlie the group-III rich surface termination layer and comprises one of (a) depositing essentially congruently evaporating oxide of at least one of (a(i)) a ternary oxide and (a(ii)) an oxide more complex than a ternary oxide and (b) depositing oxide molecules, with use of at least one of (b(i)) a ternary oxide and (b(ii)) an oxide more complex than a ternary oxide.

Abstract: A method of forming a III-V compound semiconductor structure (10) comprises providing a III-V compound semiconductor substrate including a semi-insulating substrate (12) having at least one epitaxial layer formed thereon and further having a gate insulator (14) overlying the at least one epitaxial layer. The at least one epitaxial layer formed on the semi-insulating substrate comprises an epi-structure suitable for use in the formation of a channel of a III-V compound semiconductor MOSFET device, wherein the channel (30) having a first polarity. The method further comprises forming a charge layer (22) at a surface of the gate insulator, the charge layer having a second polarity, wherein the second polarity is opposite to the first polarity.

Abstract: An improved insulated gate field effect device (60) is obtained by providing a substrate (20) desirably comprising a III-V semiconductor, having a further semiconductor layer (22) on the substrate (20) adapted to contain the channel (230) of the device (60) between spaced apart source-drain electrodes (421, 422) formed on the semiconductor layer (22). A dielectric layer (24) is formed on the semiconductor layer (22). A sealing layer (28) is formed on the dielectric layer (24) and exposed to an oxygen plasma (36). A gate electrode (482) is formed on the dielectric layer (24) between the source-drain electrodes (421, 422). The dielectric layer (24) preferably comprises gallium-oxide (25) and/or gadolinium-gallium oxide (26, 27), and the oxygen plasma (36) is preferably an inductively coupled plasma. A further sealing layer (44) of, for example, silicon nitride is desirably provided above the sealing layer (28).

Abstract: A semiconductor fabrication process includes forming a gate dielectric layer (120) overlying a substrate (101) that includes a III-V semiconductor compound. The gate dielectric layer is patterned to produce a gate dielectric structure (121) that has a substantially vertical sidewall (127), e.g., a slope of approximately 45° to 90°. A metal contact structure (130) is formed overlying the wafer substrate. The contact structure is laterally displaced from the gate dielectric structure sufficiently to define a gap (133) between the two. The wafer (100) is heat treated, which causes migration of at least one of the metal elements to form an alloy region (137) in the underlying wafer substrate. The alloy region underlies the contact structure and extends across all or a portion of the wafer substrate underlying the gap. An insulative or dielectric capping layer (140,150) is then formed overlying the wafer and covering the portion of the substrate exposed by the gap.

Abstract: Method and apparatus are described for semiconductor devices. The method (100) comprises, providing a partially completed semiconductor device (31-1) including a substrate (21), a semiconductor (22) on the substrate (21) and a passivation layer (25) on the semiconductor (22), and using a first mask (32), locally etching the passivation layer (25) to expose a portion (36) of the semiconductor (22), and without removing the first mask (32) forming a Schottky contact (42-1) of a first material on the exposed portion (36) of the semiconductor (22), then removing the first mask (32) and using a further mask (44), forming a step-gate conductor (48-1) of a second material electrically coupled to the Schottky contact (42-1) and overlying parts (25-1) of the passivation layer (25) adjacent to the Schottky contact (42-1).

Abstract: A method of forming a portion (10) of a compound semiconductor MOSFET structure comprises forming a compound semiconductor layer structure (14) and an oxide layer (20) overlying the same. Forming the compound semiconductor structure (14) includes forming at least one channel material (16) and a group-III rich surface termination layer (18) overlying the at least one channel material. Forming the oxide layer (20) includes forming the oxide layer to overlie the group-III rich surface termination layer and comprises one of (a) depositing essentially congruently evaporating oxide of at least one of (a(i)) a ternary oxide and (a(ii)) an oxide more complex than a ternary oxide and (b) depositing oxide molecules, with use of at least one of (b(i)) a ternary oxide and (b(ii)) an oxide more complex than a ternary oxide.

Abstract: A method of forming a semiconductor structure comprises forming a channel layer; forming a superlattice barrier layer overlying the channel layer, and forming a gate dielectric overlying the superlattice barrier layer. The superlattice barrier layer includes a plurality of alternating first and second layers of barrier material. In addition, the superlattice barrier layer is configured for increasing a transconductance of the semiconductor device by at least a factor of three over a semiconductor device absent such superlattice barrier layer.

Abstract: A method of forming a dielectric layer structure on a supporting semiconductor structure having a first surface comprises providing a first beam of oxide; depositing a first layer of oxide on the first surface of the supporting semiconductor structure using the first beam of oxide, wherein the first layer of oxide has a second surface; terminating the first beam of oxide, and concurrently providing a second beam of oxide, a beam of metal and a beam of oxygen, wherein the first and second beams of oxide are separate and distinct beams of oxide; and depositing a second layer of oxide on the second surface simultaneously using the second beam of oxide, the beam of metal, and the beam of oxygen.

Abstract: A III-V based, implant free MOS heterostructure field-effect transistor device comprises a gate insulator layer overlying a compound semiconductor substrate; ohmic contacts coupled to the compound semiconductor substrate proximate opposite sides of an active device region defined within the compound semiconductor substrate; and a gate metal contact electrode formed on the gate insulator layer in a region between the ohmic contacts. The ohmic contacts have portions thereof that overlap with portions of the gate insulator layer within the active device region. The overlapping portions ensure avoidance of an undesirable gap formation between an edge of the ohmic contact and a corresponding edge of the gate insulator layer.

Abstract: A method of forming a compound semiconductor device comprises forming a gate insulator layer overlying a compound semiconductor substrate, defining an active device region within the compound semiconductor substrate, forming ohmic contacts to the compound semiconductor substrate proximate opposite sides of the active device region, and forming a gate metal contact electrode on the gate insulator layer in a region between the ohmic contacts. The ohmic contacts having portions thereof that overlap with portions of the gate insulator layer within the active device region. The overlapping portions ensure an avoidance of an undesirable gap formation between an edge of the ohmic contact and a corresponding edge of the gate insulator layer.

Abstract: A method of forming a III-V compound semiconductor structure (10) comprises providing a III-V compound semiconductor substrate including a semi-insulating substrate (12) having at least one epitaxial layer formed thereon and further having a gate insulator (14) overlying the at least one epitaxial layer. The at least one epitaxial layer formed on the semi-insulating substrate comprises an epi-structure suitable for use in the formation of a channel of a III-V compound semiconductor MOSFET device, wherein the channel (30) having a first polarity. The method further comprises forming a charge layer (22) at a surface of the gate insulator, the charge layer having a second polarity, wherein the second polarity is opposite to the first polarity.

Abstract: A compound semiconductor structure is provided, which includes a GaAs-based supporting semiconductor structure having a surface on which a dielectric material is to be formed. A first layer of gallium oxide is located on the surface of the supporting semiconductor structure to form an interface therewith. A second layer of a Ga—Gd oxide is disposed on the first layer. The GaAs-based supporting semiconductor structure may be a GaAs-based heterostructure such as an at least partially completed semiconductor device (e.g., a metal-oxide field effect transistor, a heterojunction bipolar transistor, or a semiconductor laser). In this manner a dielectric layer structure is provided which has both a low defect density at the oxide-GaAs interface and a low oxide leakage current density because the dielectric structure is formed from a layer of Ga2O3 followed by a layer of Ga—Gd-oxide.

Abstract: In one embodiment, a semiconductor device (500) includes a buffer layer (504) formed over a substrate (502). An AlxGa1?xAs layer (506) is formed over the buffer layer (504) and has a first doped region (508) formed therein. An InxGa1?xAs channel layer (512) is formed over the AlxGa1?xAs layer (506). An AlxGa1?xAs layer (518) is formed over the InxGa1?xAs channel layer (512), and the AlxGa1?xAs layer (518) has a second doped region formed therein. A GaAs layer (520) having a first recess is formed over the AlxGa1?xAs layer (518). A control electrode (526) is formed over the AlxGa1?xAs layer (518). A doped GaAs layer (524) is formed over the undoped GaAs layer (520) and on opposite sides of the control electrode (526) and provides first and second current electrodes. When used to amplify a digital modulation signal, the semiconductor device (500) maintains linear operation over a wide temperature range.