Method for preparing large-area beta-phase indium selenide single crystal film

Abstract

The invention relates to a method for preparing a large-area beta-phase In2Se3 single crystal film. The method comprises the following steps that: 1) chemical cleaning and chemical corrosion treatmentare carried out on a silicon substrate with crystal orientation of (111), so that a hydrogen-passivated silicon substrate with a clean surface can be obtained; 2) the prepared silicon substrate is transferred into a molecular beam epitaxy system, heating is performed to 180 DEG C, and degassing is performed until the vacuum degree of the system is superior to 8*10 <-10 > mbar; (3) the substrate naturally cools to a growth temperature range after the substrate is degassed, and meanwhile, an In beam source and a Se beam source are opened to grow and synthesize an In2Se3 polycrystalline film; (4) the temperature of the substrate is immediately raised to 300-350 DEG C after the growth of the polycrystalline film is finished, and subsequent annealing is carried out for 5 minutes; and 5) heating is immediately stopped after annealing is finished, and the substrate naturally cools to room temperature, so that a high-quality beta-phase In2Se3 single crystal film can be obtained. According tothe method for growing the beta-phase In2Se3 thin film, the molecular beam epitaxy technology is combined with the subsequent in-situ annealing process, and the large-area high-quality beta-phase In2Se3 single crystal thin film can be prepared on the hydrogen-passivated silicon substrate at a low temperature.

Description

technical field [0001] The invention belongs to the field of semiconductor materials, and specifically relates to a method for preparing a large-area β-phase indium selenide single crystal thin film, in particular, using molecular beam epitaxy technology combined with a subsequent in-situ annealing process on a hydrogen passivated silicon (111) substrate A method for preparing high-quality β-phase indium selenide single crystal thin film materials by growing at a lower temperature. Background technique [0002] Indium selenide (chemical formula: In 2 Se 3 ) is an important class of direct bandgap semiconductor materials in the III-VI system, with five main crystal phases of α, β, γ, δ and κ. Among them, the β-phase indium selenide whose crystal space group is 3R (hereinafter referred to as β-In 2 Se 3 ) is in a metastable state at normal temperature and pressure, and has the lowest resistivity among the five known indium selenide crystal phases. Due to the metastable β-...

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Problems solved by technology

[0010] Preparation of β-In for current growth 2 Se 3 In the thin film technology, the film area is small, the crystal quality is not high, and there are many problems such as impurities. The present invention provides a method of using molecular beam epitaxy growth technology combined with ultra-high vacuum in-situ heat treatment process to grow on a silicon (111) substrate. Preparation of large area β-In 2 Se 3 single crystal thin film method

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