Method for preparing face-centered cubic phase silicon crystal film

Abstract

The invention discloses a method for preparing a face-centered cubic phase silicon crystal film. The method comprises the following steps: performing co-sputtering on a Si target and a Al target under the pressure of 0.1-20Pa, wherein the sputtering power of the aluminum target is 30-200W, and the sputtering power of the silicon target is 80-300W; performing deposition on the surface of a substrate to obtain a AlxSi1-x mixed film, wherein 0.05<x<0.8; and annealing the obtained AlxSi1-x mixed film to obtain the face-centered cubic phase silicon crystal film. By adopting the method for preparing the face-centered cubic phase silicon crystal film, the film can be prepared under normal pressure, the film contains significant face-centered cubic phase silicon crystal, and the thickness of the film can reach more than 500nm and meet the requirement of application level of devices.

Description

technical field [0001] The invention relates to the field of preparation of silicon crystal thin films, in particular to a preparation method of a face-centered cubic phase silicon crystal thin film. Background technique [0002] Silicon material is the most important and widely used semiconductor material today, and its crystal structure is diamond phase structure. In fact, the diamond phase is the atmospheric phase of silicon. As the pressure increases, the silicon crystal will transform from diamond phase to β-tin phase, simple hexagonal phase, body-centered cubic phase, close-packed hexagonal phase, face-centered cubic phase and other high-pressure phase structures (Yin and Cohen 1982, Chang and Cohen 1985, Mercer Jr and Chou 1993, Needs and Mujica 1995), the face-centered cubic phase is the high-pressure phase with the highest equilibrium phase transition pressure, and it is also the most studied high-pressure phase silicon material so far. [0003] High-pressure phas...

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Problems solved by technology

However, the face-centered cubic silicon crystal materials prepared by these methods are still difficult to use in semiconductor devices, and the corresponding disadvantages are as follows: laser ablation of the silicon wafer surface method can only prepare a small amount of dispersed face-centered cubic phase Silicon nanoparticles; microwave radio frequency assisted vapor deposition silicon film method can only prepare silicon films mixed with diamond phase and face-centered cubic phase, and the content of face-centered cubic silicon crystals is very low and there is no complete granular crystal; large lining The bottom bias assisted magnetron sputtering method uses a substrate bias voltage close to 1000V, the film is severely bombarded by ions, and the face-centered cubic phase crystals are embedded in SiO x Medium but not conductive; ion beam irradiation method SiO x Films likewise can only be obtained embedded in SiO x Face-centered cubic silicon crystals in ; rapid annealing of SiC x The face-centered cubic silicon crystals obtained by the thin-film method are embedded in SiC in the thin film, and the crystal content is very low, only distributed within tens of nanometers on the surface of the thin film

In general, the problems in the above method can be roughly attributed to the following aspects: the face-centered cubic silicon crystals of dispersed particles have a small amount, and the face-centered cubic silicon crystals embedded in the silicide film have crystals. The content is so low that the presence of face-centered cubic silicon crystals cannot be detected by grazing incidence X-rays (GI-XRD), and there are also problems such as small film thickness and poor electrical conductivity

In short, the face-centered cubic silicon crystals obtained by the above methods cannot meet the requirements of device-level applications.

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