Abstract: Methods of forming structures that include InP-based materials, such as a transistor operating as an inversion-type, enhancement-mode device are disclosed. A dielectric layer may be deposited by ALD over a semiconductor layer including In and P. A channel layer may be formed above a buffer layer having a lattice constant similar to a lattice constant of InP, the buffer layer being formed over a substrate having a lattice constant different from a lattice constant of InP.

Abstract: A transfer printing method provides a first wafer having a receiving surface, and removes a second die from a second wafer using a die moving member. Next, the method positions the second die on the receiving surface of the first wafer. Specifically, to position the second die on the receiving surface, the first wafer has alignment structure for at least in part controlling movement of the die moving member.

Abstract: A differential pair gain stage is disclosed. In one embodiment, the gain stage includes a differential pair of depletion-mode transistors, including a first and a second n-type transistor. In certain embodiments of the invention, the depletion mode transistor may be GaN (gallium nitride) field effect transistors. The gain stage includes an active load including one or more depletion mode transistors electrically coupled to at least one of the drains of depletion mode transistors of the differential pair. The active load may include a source follower for maintaining the AC voltages at the drains of the differential pair at a constant value and may further include a casocde stage for setting a fixed drain source voltage across the output transistors to increase the output impedance and gain of the stage.

Abstract: Solar cell structures including multiple sub-cells that incorporate different materials that may have different lattice constants. In some embodiments, solar cell devices include several photovoltaic junctions.

Abstract: Methods and structures are provided for formation of devices, e.g., solar cells, on substrates including, e.g., lattice-mismatched materials, by the use of aspect ratio trapping and epitaxial layer overgrowth. A method includes forming an opening in a masking layer disposed over a substrate that includes a first semiconductor material. A first layer, which includes a second semiconductor material lattice-mismatched to the first semiconductor material, is formed within the opening. The first layer has a thickness sufficient to extend above a top surface of the masking layer. A second layer, which includes the second semiconductor material, is formed on the first layer and over at least a portion of the masking layer. A vertical growth rate of the first layer is greater than a lateral growth rate of the first layer and a lateral growth rate of the second layer is greater than a vertical growth rate of the second layer.

Abstract: A method cold-melts a high conductivity region between a high-resistivity silicon substrate and a gallium-nitride layer to form a trap rich region that substantially immobilizes charge carriers in that region. Such a process should substantially mitigate the parasitic impact of that region on circuits formed at least in part by the gallium-nitride layer.

Abstract: Methods of forming structures that include InP-based materials, such as a transistor operating as an inversion-type, enhancement-mode device are disclosed. A dielectric layer may be deposited by ALD over a semiconductor layer including In and P. A channel layer may be formed above a buffer layer having a lattice constant similar to a lattice constant of InP, the buffer layer being formed over a substrate having a lattice constant different from a lattice constant of InP.

Abstract: Methods of forming structures that include InP-based materials, such as a transistor operating as an inversion-type, enhancement-mode device. A dielectric layer may be deposited by ALD over a semiconductor layer including In and P. A channel layer may be formed above a buffer layer having a lattice constant similar to a lattice constant of InP, the buffer layer being formed over a substrate having a lattice constant different from a lattice constant of InP.

Abstract: A device includes a crystalline material within an area confined by an insulator. A surface of the crystalline material has a reduced roughness. One example includes obtaining a surface with reduced roughness by using a planarization process configured with a selectivity of the crystalline material to the insulator greater than one. In a preferred embodiment, the planarization process uses a composition including abrasive spherical silica, H2O2 and water. In a preferred embodiment, the area confined by the insulator is an opening in the insulator having an aspect ratio sufficient to trap defects using an ART technique.

Abstract: A method cold-melts a high conductivity region between a high-resistivity silicon substrate and a gallium-nitride layer to form a trap rich region that substantially immobilizes charge carriers in that region. Such a process should substantially mitigate the parasitic impact of that region on circuits formed at least in part by the gallium-nitride layer.

Abstract: Strain is induced in a semiconductor layer. Embodiments include inducing strain by, for example, creation of free surfaces.

Abstract: A device includes a crystalline material within an area confined by an insulator. A surface of the crystalline material has a reduced roughness. One example includes obtaining a surface with reduced roughness by using a planarization process configured with a selectivity of the crystalline material to the insulator greater than one. In a preferred embodiment, the planarization process uses a composition including abrasive spherical silica, H2O2 and water. In a preferred embodiment, the area confined by the insulator is an opening in the insulator having an aspect ratio sufficient to trap defects using an ART technique.

Abstract: Non-silicon based semiconductor devices are integrated into silicon fabrication processes by using aspect-ratio-trapping materials. Non-silicon light-sensing devices in a least a portion of a crystalline material can output electrons generated by light absorption therein. Exemplary light-sensing devices can have relatively large micron dimensions. As an exemplary application, complementary-metal-oxide-semiconductor photodetectors are formed on a silicon substrate by incorporating an aspect-ratio-trapping technique.

Abstract: Fabrication of monolithic lattice-mismatched semiconductor heterostructures with limited area regions having upper portions substantially exhausted of threading dislocations, as well as fabrication of semiconductor devices based on such lattice-mismatched heterostructures.

Abstract: A differential pair gain stage is disclosed. In one embodiment, the gain stage includes a differential pair of depletion-mode transistors, including a first and a second n-type transistor. In certain embodiments of the invention, the depletion mode transistor may be GaN (gallium nitride) field effect transistors. The gain stage includes an active load including one or more depletion mode transistors electrically coupled to at least one of the drains of depletion mode transistors of the differential pair. The active load may include a source follower for maintaining the AC voltages at the drains of the differential pair at a constant value and may further include a casocde stage for setting a fixed drain source voltage across the output transistors to increase the output impedance and gain of the stage.

Abstract: A transfer printing method provides a first wafer having a receiving surface, and removes a second die from a second wafer using a die moving member. Next, the method positions the second die on the receiving surface of the first wafer. Specifically, to position the second die on the receiving surface, the first wafer has alignment structure for at least in part controlling movement of the die moving member.

Abstract: Fabrication of monolithic lattice-mismatched semiconductor heterostructures with limited area regions having upper portions substantially exhausted of threading dislocations, as well as fabrication of semiconductor devices based on such lattice-mismatched heterostructures.

Abstract: A device includes a crystalline material within an area confined by an insulator. A surface of the crystalline material has a reduced roughness. One example includes obtaining a surface with reduced roughness by using a planarization process configured with a selectivity of the crystalline material to the insulator greater than one. In a preferred embodiment, the planarization process uses a composition including abrasive spherical silica, H2O2 and water. In a preferred embodiment, the area confined by the insulator is an opening in the insulator having an aspect ratio sufficient to trap defects using an ART technique.

Abstract: Fabrication of monolithic lattice-mismatched semiconductor heterostructures with limited area regions having upper portions substantially exhausted of threading dislocations, as well as fabrication of semiconductor devices based on such lattice-mismatched heterostructures.

Abstract: Non-silicon based semiconductor devices are integrated into silicon fabrication processes by using aspect-ratio-trapping materials. Non-silicon light-sensing devices in a least a portion of a crystalline material can output electrons generated by light absorption therein. Exemplary light-sensing devices can have relatively large micron dimensions. As an exemplary application, complementary-metal-oxide-semiconductor photodetectors are formed on a silicon substrate by incorporating an aspect-ratio-trapping technique.