Abstract: A semiconductor wafer includes a substrate (1), a buffer layer (2) deposited on the substrate (1), and an epitaxial layer (4) above the buffer layer (2). The buffer layer (2) includes a plurality of semiconductor material layers (22) and a plurality of oxygen-doped material layers (21). The semiconductor material layers (22) and the oxygen-doped material layers (21) are deposited in an alternating arrangement on top of each other. Oxygen concentrations of the oxygen-doped material layers (21) gradually decrease along a direction from the substrate (1) to the epitaxial layer (4).

Abstract: Disclosed is a wafer or a material stack for semiconductor-based optoelectronic or electronic devices that minimizes or reduces misfit dislocation, as well as a method of manufacturing such wafer of material stack. A material stack according to the disclosed technology includes a substrate; a basis buffer layer of a first material disposed above the substrate; and a plurality of composite buffer layers disposed above the basis buffer layer sequentially along a growth direction. The growth direction is from the substrate to a last composite buffer layer of the plurality of composite buffer layers. Each composite buffer layer except the last composite buffer layer includes a first buffer sublayer of the first material, and a second buffer sublayer of a second material disposed above the first buffer sublayer. The thicknesses of the first buffer sublayers of the composite buffer layers decrease along the growth direction.

Abstract: A semiconductor wafer includes a substrate (1), a buffer layer (2) deposited on the substrate (1), and an epitaxial layer (4) above the buffer layer (2). The buffer layer (2) includes a plurality of semiconductor material layers (22) and a plurality of oxygen-doped material layers (21). The semiconductor material layers (22) and the oxygen-doped material layers (21) are deposited in an alternating arrangement on top of each other. Oxygen concentrations of the oxygen-doped material layers (21) gradually decrease along a direction from the substrate (1) to the epitaxial layer (4).

Abstract: Disclosed is a wafer or a material stack for semiconductor-based optoelectronic or electronic devices that minimizes or reduces misfit dislocation, as well as a method of manufacturing such wafer of material stack. A material stack according to the disclosed technology includes a substrate; a basis buffer layer of a first material disposed above the substrate; and a plurality of composite buffer layers disposed above the basis buffer layer sequentially along a growth direction. The growth direction is from the substrate to a last composite buffer layer of the plurality of composite buffer layers. Each composite buffer layer except the last composite buffer layer includes a first buffer sublayer of the first material, and a second buffer sublayer of a second material disposed above the first buffer sublayer. The thicknesses of the first buffer sublayers of the composite buffer layers decrease along the growth direction.

Abstract: Disclosed is a wafer or a material stack for semiconductor-based optoelectronic or electronic devices that minimizes or reduces misfit dislocation, as well as a method of manufacturing such wafer of material stack. A material stack according to the disclosed technology includes a substrate; a basis buffer layer of a first material disposed above the substrate; and a plurality of composite buffer layers disposed above the basis buffer layer sequentially along a growth direction. The growth direction is from the substrate to a last composite buffer layer of the plurality of composite buffer layers. Each composite buffer layer except the last composite buffer layer includes a first buffer sublayer of the first material, and a second buffer sublayer of a second material disposed above the first buffer sublayer. The thicknesses of the first buffer sublayers of the composite buffer layers decrease along the growth direction.

Abstract: Disclosed is a wafer or a material stack for semiconductor-based optoelectronic or electronic devices that minimizes or reduces misfit dislocation, as well as a method of manufacturing such wafer of material stack. A material stack according to the disclosed technology includes a substrate; a basis buffer layer of a first material disposed above the substrate; and a plurality of composite buffer layers disposed above the basis buffer layer sequentially along a growth direction. The growth direction is from the substrate to a last composite buffer layer of the plurality of composite buffer layers. Each composite buffer layer except the last composite buffer layer includes a first buffer sublayer of the first material, and a second buffer sublayer of a second material disposed above the first buffer sublayer. The thicknesses of the first buffer sublayers of the composite buffer layers decrease along the growth direction.

Abstract: Disclosed is a method of manufacturing a semiconductor-based wafer for reducing misfit dislocation. The method includes steps of depositing a basis buffer layer of aluminum nitride (AlN) on a substrate; forming an AlN sublayer of a composite buffer layer on the basis buffer layer by supplying pulses of reactants for AlN for a first total pulse time period; forming an gallium nitride (GaN) sublayer of the composite buffer layer on the AlN sublayer by supplying pulses of reactants for GaN for a second total pulse time period; and growing additional composite buffer layers along a growth direction from the substrate to the composite buffer layers, by repeating steps of forming the AlN sublayer and forming the GaN sublayer. The first total pulse time period for each AlN sublayer decreases among the composite buffer layers along the growth direction.