Method for epitaxially growing GeSi quantum dots

Abstract

The invention provides a method for epitaxially growing GeSi quantum dots. The method comprises the following steps of: 1) preparing a truncated inverted pyramid pattern on a silicon substrate by adopting a photoetching and wet etching combined technology to obtain a patterned substrate, wherein the crystal faces of the four side faces of the truncated inverted pyramid are (111) faces; 2) removingthe mask subjected to wet etching on the patterned substrate, and cleaning the patterned substrate; 3) placing the patterned substrate in an epitaxial growth device, and directly carrying out heteroepitaxy on GeSi quantum dots on the truncated inverted pyramid patterned substrate; and 4) epitaxially growing a silicon cover layer on the GeSi quantum dots. According to the method provided by the invention, the defects that the surface of the substrate is damaged by dry etching and the feature size of grown quantum dots is too large due to the fact that the feature size of the patterned substrate prepared by wet etching is too large are avoided; and the quantum dots grown by adopting the method provided by the invention are consistent in size, and the positions of the quantum dots are highlysymmetrical, so that quadruplicated frequency of quantum dot growth is realized.

Description

technical field [0001] The invention belongs to the technical field of semiconductors. In particular, the present invention relates to methods of epitaxial GeSi quantum dots. Background technique [0002] As the most important semiconductor material at present, silicon occupies a mainstream position in the field of microelectronic device materials. With the continuous improvement of integrated circuit integration and the continuous shrinking of the size of electronic devices, the problem of RC delay is becoming more and more serious. This effect seriously restricts the ability of electronic transmission of information. In order to break through this bottleneck, a new information carrier needs to be found, and photons are the preferred object. Thanks to the development of micro-nano processing technology, silicon-based photonics has achieved a blowout development in the past ten years. At present, silicon-based optoelectronic devices have covered the fields of light emissio...

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Problems solved by technology

[0004] However, there are certain problems in growing quantum dots on patterned substrates.

Dry etching can produce patterns with characteristic sizes of tens of nanometers, which are used to grow quantum dots of tens of nanometers. However, during the dry etching process, damage and contamination will inevitably be introduced on the growth surface; wet etching can also prepare patterns. At the same time, compared with dry etching, the surface damage can be reduced, but due to the inevitable lateral undercutting due to wet etching, it is difficult to prepare graphics with a feature size of less than 100 nanometers due to the expansion of the size of the graphics substrate. The size of the bottom-grown quantum dots is too large, and the quantum effect is not obvious

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