The present disclosure provides a fabricating method of a high electron mobility transistor device, including a substrate, a nucleation layer, a buffer layer, an active layer and a gate electrode. The nucleation layer is disposed on the substrate, and the buffer layer is disposed on the nucleation layer, wherein the buffer layer includes a first superlattice layer having at least two heteromaterials alternately arranged in a horizontal direction, and a second superlattice layer having at least two heteromaterials vertically stacked along a vertical direction. The at least two heteromaterials stack at least once within the second superlattice layer. The active layer is disposed on the buffer layer, and the gate electrode is disposed on the active layer.

A method for manufacturing a silicon substrate for a quantum computer, the method includes the steps of forming a Si epitaxial layer by epitaxial growth using a Si source gas as a silicon-based raw material gas, in which a total content of 28Si and 30Si in a whole silicon contained in the silicon-based raw material gas is 99.9% or more, on a silicon substrate, forming an oxygen (O) -doped layer by oxidizing a surface of the Si epitaxial layer, and forming a Si epitaxial layer by epitaxial growth using a Si source gas, in which a total content of 28Si and 30Si in a whole silicon contained in the silicon-based raw material gas is 99.9% or more, on the -doped layer.

Methods for forming structures that include forming a heteroepitaxial layer on a substrate are disclosed. The presently disclosed methods comprise epitaxially forming a buffer layer on the substrate. The substrate has a substrate composition. The buffer layer has a buffer layer composition. The buffer layer composition is substantially identical to the substrate composition. The presently disclosed methods further comprise epitaxially forming a heteroepitaxial layer on the buffer layer. The heteroepitaxial layer has a heteroepitaxial layer composition which is different from the substrate composition.

A method for making a semiconductor device may include forming a superlattice gettering layer on a substrate. The superlattice may include a plurality of stacked groups of layers, with each group of layers comprising a plurality of stacked base semiconductor monolayers defining a base semiconductor portion, and at least one non-semiconductor monolayer constrained within a crystal lattice of adjacent base semiconductor portions. The method may also include forming a memory device above the superlattice gettering layer including a metal induced crystallization (MIC) channel adjacent the semiconductor substrate, and a gate associated with the MIC channel. The superlattice gettering layer may further include gettered metal particles from the MIC channel.