Semiconductor device having a channel for a zero-or one-dimensional carrier gas

Abstract

An undoped GaAs layer is epitaxially grown on a substrate in a crystal growth device. An undoped Al.sub.x Ga.sub.1-x As layer is then epitaxially grown to form an undoped hetero-junction structure. After this, a sample is transferred to a focused ion beam (FIB) apparatus. A dopant ion beam is focused and implanted into the Al.sub.x Ga .sub.1-x As layer in a dot-like or wire-like pattern so that it does not extend to the undoped GaAs layer or channel layer, and a zero- or one-dimensional carrier gas 8 is generated in the channel layer. The invention allows maskless ion implantation, and makes the fabrication process much easier because quantum wires and dots are drawn, patterned or formed directly by ion implantation. In addition, no etching process is required, so quantum wires and quantum dots can be fabricated precisely. Furthermore, since there is no influence of the impurity scattering and damage by ion implantation in the channel where electrons and holes are transported, high mobility is obtained and a high-speed device can be fabricated. The invention overcomes the problem of crystal damage in prior processes that required chemical etching and ion implantation.

Dependencies are inferred from the claim text.