Preparation method of Si substrate AlN template and preparation method of Si substrate GaN epitaxial structure

Abstract

The invention discloses a preparation method of a Si substrate AlN template and a preparation method of a Si substrate GaN epitaxial structure. The preparation method of the Si substrate AlN templatecomprises the following steps: selecting a Si substrate; growing an AlN nucleating layer on the Si substrate; and injecting ions into the Si substrate through the AlN nucleating layer. After the AlN nucleating layer is prepared on the Si substrate, ion implantation on the Si substrate and injecting ions into the AlN nucleating layer are performed through the AlN nucleating layer, so that the typesof the ions injected in the mode can be expanded, the carrier concentration at the Si / AlN interface and the carrier concentration in the AlN nucleating layer can also be reduced, the radio frequencyloss of the Si substrate AlN template is reduced, the characteristics of a GaN microwave device manufactured by using the Si substrate AlN template are improved, and the application requirements of the GaN microwave device in the fields of aerospace, radar, mobile communication and the like are met. In addition, a GaN device epitaxial structure is prepared by using the Si substrate AlN template, and the design of the GaN device epitaxial structure has more degrees of freedom.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and in particular relates to a method for preparing an AlN template on a Si substrate and a method for preparing a GaN epitaxial structure on an Si substrate. Background technique [0002] The third-generation semiconductor material GaN has the advantages of wide band gap, high critical breakdown field strength, high electron mobility, and high saturation electron drift velocity. It has great development potential in the field of microwave and millimeter wave high-power electronic devices and can be widely used. In aerospace, radar, 5G communication and other fields. There are two types of GaN epitaxial wafers: homoepitaxy and heteroepitaxy. Due to the high cost of GaN homoepitaxy, the commonly used technology is heteroepitaxy. Commonly used substrates for GaN heteroepitaxy include sapphire, SiC and Si, etc. Compared with other substrates, Si substrates have larger size, lower cost and ar...

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Problems solved by technology

This patent does not propose to deal with the background carrier concentration in the III-nitride material, and the background carrier concentration in the III-nitride material is also an important part of the electromagnetic loss of the GaN device on the Si substrate.

Moreover, ion implantation is performed after the epitaxial growth of the AlGaN transition layer. Because the nitride layer is too thick, if the relative atomic mass of the implanted ions is greater than 5, the implantation depth is limited, so that it cannot be implanted at the AlN / Si interface. Therefore It is necessary to limit the implanted ion species to elements with a relative atomic weight less than 5, which reduces the number and selection of implanted ion species, and the ion implantation is performed after the epitaxial growth of the AlGaN transition layer, and the surface of the material will adsorb impurity ions. When continuing to epitaxially grow the GaN buffer layer and the subsequent device heterojunction structure, impurity ions will diffuse into the GaN buffer layer and device heterojunction structure, thereby affecting the performance of the device

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