A method of manufacture and structure for a monolithic single chip single crystal device. The method can include forming a first single crystal epitaxial layer overlying the substrate and forming one or more second single crystal epitaxial layers overlying the first single crystal epitaxial layer. The first single crystal epitaxial layer and the one or more second single crystal epitaxial layers can be processed to form one or more active or passive device components. Through this process, the resulting device includes a monolithic epitaxial stack integrating multiple circuit functions.

A semiconductor thin film structure may include a substrate, a buffer layer on the substrate, and a semiconductor layer on the buffer layer, such that the buffer layer is between the semiconductor layer and the substrate. The buffer layer may include a plurality of unit layers. Each unit layer of the plurality of unit layers may include a first layer having first bandgap energy and a first thickness, a second layer having second bandgap energy and a second thickness, and a third layer having third bandgap energy and a third thickness. One layer having a lowest bandgap energy of the first, second, and third layers of the unit layer may be between another two layers of the first, second, and third layers of the unit layer.

Disclosed is a preparation method for a semiconductor structure. The semiconductor structure includes: a substrate; an epitaxial layer and an epitaxial structure that are stacked on the substrate in sequence. The epitaxial layer is doped with a doping element. In the forming process, a sacrificial layer is formed on the epitaxial layer, and the sacrificial layer is repeatedly etched, such that a concentration of the doping element in the epitaxial layer is lower than a preset value. In this application, the sacrificial layer is formed on the epitaxial layer, and the sacrificial layer is repeatedly etched, such that the concentration of the doping element in the epitaxial layer is lower than the preset value, so as to prevent the doping element in the epitaxial layer from being precipitated upward into an upper-layer structure, ensure the mobility of electrons in a channel layer, and improve the performance of a device.

A SiC epitaxial wafer includes a SiC substrate and an epitaxial layer laminated on the SiC substrate, wherein the epitaxial layer contains an impurity element which determines the conductivity type of the epitaxial layer and boron which has a conductivity type different from the conductivity type of the impurity element, and the concentration of boron in the center of the epitaxial layer is less than 5.0×10.sup.12 cm.sup.−3.

A SiC epitaxial wafer includes a SiC substrate and an epitaxial layer laminated on the SiC substrate, wherein the epitaxial layer contains an impurity element which determines the conductivity type of the epitaxial layer and boron which has a conductivity type different from the conductivity type of the impurity element, and the concentration of boron is less than 1.0×10.sup.14 cm.sup.−3 at any position in the plane of the epitaxial layer.

A semiconductor laminate includes a silicon carbide substrate having a first main surface and a second main surface opposite the first main surface, and an epitaxial layer composed of silicon carbide disposed on the first main surface. The second main surface has an average value of roughness Ra of 0.1 μm or more and 1 μm or less with a standard deviation of 25% or less of the average value.

A method for manufacturing an epitaxial wafer comprising a silicon carbide substrate and a silicon carbide voltage-blocking-layer, the method includes: epitaxially growing a buffer layer on the substrate, doping a main dopant for determining a conductivity type of the buffer layer and doping an auxiliary dopant for capturing minority carriers in the buffer layer at a doping concentration less than the doping concentration of the main dopant, so that the buffer layer enhances capturing and extinction of the minority carriers, the minority carriers flowing in a direction from the voltage-blocking-layer to the substrate, so that the buffer layer has a lower resistivity than the voltage-blocking-layer, and so that the buffer layer includes silicon carbide as a main component; and epitaxially growing the voltage-blocking-layer on the buffer layer.

A silicon carbide crystal includes a seed layer, a bulk layer, and a stress buffering structure formed between the seed layer and the bulk layer. The seed layer, the bulk layer, and the stress buffering structure are each formed with a dopant that cycles between high and low dopant concentration. The stress buffering structure includes a plurality of stacked buffer layers and a transition layer over the buffer layers. The buffer layer closest to the seed layer has the same variation trend of the dopant concentration as the buffer layer closest to the transition layer, and the dopant concentration of the transition layer is equal to the dopant concentration of the seed layer.

A method for manufacturing an epitaxial substrate includes the steps of: epitaxially growing a group III nitride semiconductor layer on a substrate; removing the substrate from a growth furnace; irradiating a surface of the group III nitride semiconductor layer with ultraviolet light while exposing the surface to an atmosphere containing oxygen; and measuring a sheet resistance value of the group III nitride semiconductor layer.

A method for producing a silicon carbide component includes forming a silicon carbide layer on an initial wafer, forming a doping region of the silicon carbide component to be produced in the silicon carbide layer, and forming an electrically conductive contact structure of the silicon carbide component to be produced on a surface of the silicon carbide layer. The electrically conductive contact structure electrically contacts the doping region. Furthermore, the method includes splitting the silicon carbide layer or the initial wafer after forming the electrically conductive contact structure, such that a silicon carbide substrate at least of the silicon carbide component to be produced is split off.