Abstract: A trench comprising a portion of a substrate is formed. A nucleation layer is deposited on the portion of the substrate within the trench. A III-N material layer is deposited on the nucleation layer. The III-N material layer is laterally grown over the trench. A device layer is deposited on the laterally grown III-N material layer. A low defect density region is obtained on the laterally grown material and is used for electronic device fabrication of III-N materials on Si substrates.

Abstract: Trenches (and processes for forming the trenches) are provided that reduce or prevent crystaline defects in selective epitaxial growth of type III-V or Germanium (Ge) material (e.g., a “buffer” material) from a top surface of a substrate material. The defects may result from collision of selective epitaxial sidewall growth with oxide trench sidewalls. Such trenches include (1) a trench having sloped sidewalls at an angle of between 40 degrees and 70 degrees (e.g., such as 55 degrees) with respect to a substrate surface; and/or (2) a combined trench having an upper trench over and surrounding the opening of a lower trench (e.g., the lower trench may have the sloped sidewalls, short vertical walls, or tall vertical walls). These trenches reduce or prevent defects in the epitaxial sidewall growth where the growth touches or grows against vertical sidewalls of a trench it is grown in.

Abstract: Techniques are disclosed for forming a defect-free semiconductor structure on a dissimilar substrate with a multi-aspect ratio mask. The multi-aspect ratio mask comprises a first, second, and third layer formed on a substrate. The second layer has a second opening wider than a first opening and a third opening in the first and third layers, respectively. All three openings are centered along a common central axis. A semiconductor material is grown from the top surface of the substrate and laterally onto the top surface of the first layer within the second opening. The semiconductor material disposed within and vertically below the third opening is etched by using the third layer as an etch mask so that the remaining material that laterally overflowed onto the top surface of the first layer forms a remaining structure.

Abstract: An insulating layer is conformally deposited on a plurality of mesa structures in a trench on a substrate. The insulating layer fills a space outside the mesa structures. A nucleation layer is deposited on the mesa structures. A III-V material layer is deposited on the nucleation layer. The III-V material layer is laterally grown over the insulating layer.

Abstract: Transistors or transistor layers include an InAlN and AlGaN bi-layer capping stack on a 2DEG GaN channel, such as for GaN MOS structures on Si substrates. The GaN channel may be formed in a GaN buffer layer or stack, to compensate for the high crystal structure lattice size and coefficient of thermal expansion mismatch between GaN and Si. The bi-layer capping stack an upper InAlN layer on a lower AlGaN layer to induce charge polarization in the channel, compensate for poor composition uniformity (e.g., of Al), and compensate for rough surface morphology of the bottom surface of the InAlN material. It may lead to a sheet resistance between 250 and 350 ohms/sqr. It may also reduce bowing of the GaN on Si wafers during growth of the layer of InAlN material, and provide a AlGaN setback layer for etching the InAlN layer in the gate region.

Abstract: Techniques are disclosed for forming a GaN transistor on a semiconductor substrate. An insulating layer forms on top of a semiconductor substrate. A trench, filled with a trench material comprising a III-V semiconductor material, forms through the insulating layer and extends into the semiconductor substrate. A channel structure, containing III-V material having a defect density lower than the trench material, forms directly on top of the insulating layer and adjacent to the trench. A source and drain form on opposite sides of the channel structure, and a gate forms on the channel structure. The semiconductor substrate forms a plane upon which both GaN transistors and other transistors can form.

Abstract: A trench comprising a portion of a substrate is formed. A nucleation layer is deposited on the portion of the substrate within the trench. A III-N material layer is deposited on the nucleation layer. The III-N material layer is laterally grown over the trench. A device layer is deposited on the laterally grown III-N material layer. A low defect density region is obtained on the laterally grown material and is used for electronic device fabrication of III-N materials on Si substrates.

Abstract: Techniques are disclosed for forming a GaN transistor on a semiconductor substrate. An insulating layer forms on top of a semiconductor substrate. A trench, filled with a trench material comprising a III-V semiconductor material, forms through the insulating layer and extends into the semiconductor substrate. A channel structure, containing III-V material having a defect density lower than the trench material, forms directly on top of the insulating layer and adjacent to the trench. A source and drain form on opposite sides of the channel structure, and a gate forms on the channel structure. The semiconductor substrate forms a plane upon which both GaN transitors and other transistors can form.

Abstract: A III-N semiconductor channel is compositionally graded between a transition layer and a III-N polarization layer. In embodiments, a gate stack is deposited over sidewalls of a fin including the graded III-N semiconductor channel allowing for formation of a transport channel in the III-N semiconductor channel adjacent to at least both sidewall surfaces in response to a gate bias voltage. In embodiments, a gate stack is deposited completely around a nanowire including a III-N semiconductor channel compositionally graded to enable formation of a transport channel in the III-N semiconductor channel adjacent to both the polarization layer and the transition layer in response to a gate bias voltage.

Abstract: Techniques are disclosed for forming a defect-free semiconductor structure on a dissimilar substrate with a multi-aspect ratio mask. The multi-aspect ratio mask comprises a first, second, and third layer formed on a substrate. The second layer has a second opening wider than a first opening and a third opening in the first and third layers, respectively. All three openings are centered along a common central axis. A semiconductor material is grown from the top surface of the substrate and laterally onto the top surface of the first layer within the second opening. The semiconductor material disposed within and vertically below the third opening is etched by using the third layer as an etch mask so that the remaining material that laterally overflowed onto the top surface of the first layer forms a remaining structure.

Abstract: Enhancement mode gallium nitride (GaN) semiconductor devices having a composite high-k metal gate stack and methods of fabricating such devices are described. In an example, a semiconductor device includes a gallium nitride (GaN) channel region disposed above a substrate. A gate stack is disposed on the GaN channel region. The gate stack includes a composite gate dielectric layer disposed directly between the GaN channel region and a gate electrode. The composite gate dielectric layer includes a high band gap Group III-N layer, a first high-K dielectric oxide layer, and a second high-K dielectric oxide layer having a higher dielectric constant than the first high-K dielectric oxide layer. Source/drain regions are disposed on either side of the GaN channel region.

Abstract: Trenches (and processes for forming the trenches) are provided that reduce or prevent crystaline defects in selective epitaxial growth of type III-V or Germanium (Ge) material (e.g., a “buffer” material) from a top surface of a substrate material. The defects may result from collision of selective epitaxial sidewall growth with oxide trench sidewalls. Such trenches include (I) a trench having sloped sidewalls at an angle of between 40 degrees and 70 degrees (e.g., such as 55 degrees) with respect to a substrate surface; and/or (2) a combined trench having an upper trench over and surrounding the opening of a lower trench (e.g., the lower trench may have the sloped sidewalls, short vertical walls, or tall vertical walls). These trenches reduce or prevent defects in the epitaxial sidewall growth where the growth touches or grows against vertical sidewalls of a trench it is grown in.

Abstract: An insulating layer is conformally deposited on a plurality of mesa structures in a trench on a substrate. The insulating layer fills a space outside the mesa structures. A nucleation layer is deposited on the mesa structures. A III-V material layer is deposited on the nucleation layer. The III-V material layer is laterally grown over the insulating layer.

Abstract: A III-N semiconductor channel is compositionally graded between a transition layer and a III-N polarization layer. In embodiments, a gate stack is deposited over sidewalls of a fin including the graded III-N semiconductor channel allowing for formation of a transport channel in the III-N semiconductor channel adjacent to at least both sidewall surfaces in response to a gate bias voltage. In embodiments, a gate stack is deposited completely around a nanowire including a III-N semiconductor channel compositionally graded to enable formation of a transport channel in the III-N semiconductor channel adjacent to both the polarization layer and the transition layer in response to a gate bias voltage.

Abstract: A fin over an insulating layer on a substrate having a first crystal orientation is modified to form a surface aligned along a second crystal orientation. A device layer is deposited over the surface of the fin aligned along the second crystal orientation.

Abstract: A trench comprising a portion of a substrate is formed. A nucleation layer is deposited on the portion of the substrate within the trench. A III-N material layer is deposited on the nucleation layer. The III-N material layer is laterally grown over the trench. A device layer is deposited on the laterally grown III-N material layer. A low defect density region is obtained on the laterally grown material and is used for electronic device fabrication of III-N materials on Si substrates.

Abstract: Transistors or transistor layers include an InAlN and AlGaN bi-layer capping stack on a 2DEG GaN channel, such as for GaN MOS structures on Si substrates. The GaN channel may be formed in a GaN buffer layer or stack, to compensate for the high crystal structure lattice size and coefficient of thermal expansion mismatch between GaN and Si. The bi-layer capping stack an upper InAlN layer on a lower AlGaN layer to induce charge polarization in the channel, compensate for poor composition uniformity (e.g., of Al), and compensate for rough surface morphology of the bottom surface of the InAlN material. It may lead to a sheet resistance between 250 and 350 ohms/sqr. It may also reduce bowing of the GaN on Si wafers during growth of the layer of InAlN material, and provide a AlGaN setback layer for etching the InAlN layer in the gate region.

Abstract: A III-N semiconductor channel is compositionally graded between a transition layer and a III-N polarization layer. In embodiments, a gate stack is deposited over sidewalls of a fin including the graded III-N semiconductor channel allowing for formation of a transport channel in the III-N semiconductor channel adjacent to at least both sidewall surfaces in response to a gate bias voltage. In embodiments, a gate stack is deposited completely around a nanowire including a III-N semiconductor channel compositionally graded to enable formation of a transport channel in the III-N semiconductor channel adjacent to both the polarization layer and the transition layer in response to a gate bias voltage.

Abstract: A III-N semiconductor channel is compositionally graded between a transition layer and a III-N polarization layer. In embodiments, a gate stack is deposited over sidewalls of a fin including the graded III-N semiconductor channel allowing for formation of a transport channel in the III-N semiconductor channel adjacent to at least both sidewall surfaces in response to a gate bias voltage. In embodiments, a gate stack is deposited completely around a nanowire including a III-N semiconductor channel compositionally graded to enable formation of a transport channel in the III-N semiconductor channel adjacent to both the polarization layer and the transition layer in response to a gate bias voltage.

Abstract: An embodiment includes depositing a material onto a substrate where the material includes a different lattice constant than the substrate (e.g., III-V or IV epitaxial (EPI) material on a Si substrate). An embodiment includes an EPI layer formed within a trench having walls that narrow as the trench extends upwards. An embodiment includes an EPI layer formed within a trench using multiple growth temperatures. A defect barrier, formed in the EPI layer when the temperature changes, contains defects within the trench and below the defect barrier. The EPI layer above the defect barrier and within the trench is relatively defect free. An embodiment includes an EPI layer annealed within a trench to induce defect annihilation. An embodiment includes an EPI superlattice formed within a trench and covered with a relatively defect free EPI layer (that is still included in the trench). Other embodiments are described herein.