Method for preparing high quality ZnO single crystal thin film on (La, Sr) (Al, Ta) O3

Abstract

The prodn. steps are: 1) to do low-temp. oxygen plasma preprocessing to LSAT(111) substrate surface, 2) to deposit magnesium ultrathin layer in ultrahigh vacuum and low temp., 3) to do annealing process to magnesium ultrathin layer by increasing substrate temp. to make magnesium atoms moving and deabsorbing on LSAT (111) substrate, 4) to obtain ultrathin magnesium adsorption layer, thus to realize that ZnO film grows according to crystal lattice small mismatch and epitaxial orientation to produce atom grade smooth high-quality ZnOfilm with single O polarity and domain. The smooth ZnO film produced by the invention has high crystal quality and photoelectric performance.

Description

technical field [0001] The invention relates to a method for preparing a wide bandgap semiconductor zinc oxide (ZnO) single crystal film, especially in (La, Sr) (Al, Ta) O 3 (LSAT for short) (111) A method for obtaining high-quality ZnO single crystal thin films by controlling epitaxial orientation, eliminating spin domains, and controlling polarity when preparing zinc oxide thin films on substrates. Background technique [0002] ZnO has a variety of superior properties and is widely used in transparent conductive films, surface acoustic wave devices and piezoelectric ceramics. ZnO is also a direct transition II-VI semiconductor with a band gap of 3.37eV at room temperature. Due to its high free exciton binding energy (60meV), ZnO has become another important wide-bandgap semiconductor material after GaN, and has a very broad application prospect in the preparation of low-threshold, high-efficiency short-wavelength optoelectronic devices. The preparation of device-quality ...

AI Technical Summary

Problems solved by technology

However, the in-plane orientation relationship between the ZnO epitaxial film grown along the c-axis and the LSAT(111) substrate prepared by the existing method is often inconsistent with the above ideal situation, and the in-plane epitaxial orientation is ZnO‖ LSAT and ZnO‖LSAT, there is a 30° rotation from the ideal, resulting in a lattice mismatch of up to 18.9%

Therefore, the obtained ZnO epitaxial film has problems such as large film strain and high defect density caused by large lattice mismatch, and its crystal quality and photoelectric performance are very poor.

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