Production of ZnO metal Schottky-based contact and its use in ultraviolet detector

Abstract

The invention is concerned with a method to form Schottky contacts by in-situ producing metal thin film electrode on ZnO crystal thin film surface with MBE low temperature growth method, especially a method to use ultra-high vacuum in-situ depositing metal conduct thin film. Use ultra-high vacuum sample-feeding system and send ZnO crystal thin film sample produced in MBE growth room to electrode evaporation room during ultra-high vacuum. The sample table can cool and maintain the ZnO thin film sample under the room temperature(<=20 degree), then the deposition of metal thin film can be carried by MBE method with low temperature. The ZnO surface with continuous and equably deposit metal conductive film can be prepared and can be used to produce and research the metal-semiconductor Schottky contacts and other devices, especially ZnO base ultraviolet detector with high photo-electricity responsivity with good schottky junction fromed by silver and n tape of ZnO.

Description

technical field [0001] The invention relates to a method for preparing a metal Schottky contact on the surface of a ZnO single crystal film, especially in an ultra-high vacuum environment, using molecular beam epitaxy technology to deposit a metal film at a low temperature in situ on a ZnO clean surface to prepare a Schottky contact Contact, and further methods of fabricating UV detectors. Background technique [0002] As the core basic material of the third-generation semiconductor, ZnO has very superior photoelectric properties. Its room temperature bandgap is 3.37eV and the free exciton binding energy is 60meV. An important wide-bandgap semiconductor material has a very broad application prospect in the field of low-threshold, high-efficiency short-wavelength optoelectronic devices. At present, the two most promising potential applications of ZnO in the world are ZnO-based ultraviolet detectors and ZnO-based short-wavelength laser diodes (LEDs). [0003] Because ZnO has...

AI Technical Summary

Problems solved by technology

This method is easy to damage the surface of the single crystal substrate, resulting in a large number of defects, which is not conducive to obtaining a good metal-semiconductor contact

In addition, the magnetron sputtering coating method is used for electrode deposition under a rough vacuum with a pressure of about 1 Pa. The surface of the substrate has been polluted to a certain extent, which cannot protect the clean surface of the ZnO sample, let alone achieve in-situ Electrode deposition

The limitations of the thermal evaporation method are: 1. The vapor pressure of refractory metals is low, and it is difficult to form thin films; 2. Some elements are easy to form alloys with heating wires; 3. It is difficult to obtain alloy films with uniform composition

In addition, due to its fast deposition rate, the metal electrode is a polycrystalline phase, which does not take advantage of the formation of good contact properties.

The electron beam evaporation method is generally not used for depositing metals with lower melting points, such as gold and silver, due to its high cost.

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