Method for preparing thin film material of metal zirconium

Abstract

This invention provides a preparation method for zirconium thin films. A dual ion beam epitaxy apparatus with the function of mass separation and characteristics of energetic ion deposition is adopted and zirconium chloride of which purity is not highly required serves as raw materials and is sputtered to a sanitized substrate with single isotopic pure low-energy argon ion beam. First, a thin film of zirconium nitride as block layer and buffer layer preventing reactions between zirconium ion and the substrate is prepared with the consequent isotopic pure low-energy zirconium ion beam and nitrogen ion beam, and then a zirconium film is deposited by epitaxy of single isotopic pure low-energy zirconium ion beam. By exactly controlling the energy of zirconium ion beam, the amount of deposition agents, beam density, beam shape and growing temperature, low-cost deposition and low-temperature epitaxy of zirconium which has a high melting point and is difficult to purify can be realized in ultravacuum cultivation room with high purity and high crystallization quality. This technique is convenient to modulate and optimized and is economical to manufacture zirconium thin films.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, in particular to a method for preparing difficult-to-purify and high-melting-point metal zirconium (Zr) film materials by using ion beam epitaxy (IBE) growth equipment. Background technique [0002] Group IVB refractory metal zirconium (Zr) is an important strategic material. Its metals and compounds are widely used in many fields of national economy and national defense construction. Especially, with the rapid development of information electronic technology in recent years, its role in semiconductor technology The application in the field has attracted more and more attention. For example, in the field of microelectronics, the continuous increase in the scale of ultra-large-scale integrated circuits (ULSI) has led to the continuous reduction of device feature sizes, which requires the search for new insulating gates with better performance and suitable for small-scale applications. Mate...

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Problems solved by technology

As far as the most commonly used magnetron sputtering method in the preparation of metal zirconium thin films is concerned, the preparation of high melting point metal zirconium targets by smelting is complicated. The preparation process of metal zirconium targets is also easy to be oxidized, and the purity is difficult to guarantee.

The high cost problem caused by the difficult purification of raw materials has greatly restricted the wide application and promotion of metal zirconium thin films in the semiconductor field;

[0005] 2) The existing common preparation and growth methods usually grow in a relatively low vacuum environment with auxiliary working gas, so it is not conducive to obtaining high-purity and high-quality crystallization films

The introduction of impurities, especially oxygen, will reduce the crystalline quality and electrical conductivity of the film, thereby affecting the device performance;

[0006] 3) The growth temperature of the existing common preparation and growth methods is usually high. In the initial stage of growth, silicide or other intermediate compounds are likely to be formed at the interface, which increases the contact resistance and affects the quality of subsequent film growth. , requires a low substrate temperature (below 560°C), which is also a requirement of current microelectronics technology;

[0007] 4) The existing commonly used preparation and growth methods are not satisfactory in reducing the internal stress in the metal zirconium film layer and improving the flatness of the film surface.

Mass-separated low-energy ion beam epitaxy has been successful in the growth and preparation of rare earth thin film materials, but there are few reports on how to use this method to grow refractory metal thin films of transition group IVB with high melting point and difficult to purify

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