A method and application of using magnetron sputtering to prepare metal zirconium thin film on silicon substrate

Abstract

The invention discloses a method for preparing a metal zirconium thin film on a silicon substrate by magnetron sputtering, comprising: 1 baking the silicon substrate at a high temperature; 1. Perform reverse sputtering dry cleaning on the silicon substrate under the reverse sputtering power; 3. Perform radio frequency magnetron sputtering pretreatment on the metal zirconium target under the second sputtering power; 4. Use radio frequency magnetron sputtering under the third sputtering power Magnetron sputtering pre-deposits a thin metal zirconium layer on the surface of the silicon substrate; 5 feeds the mixed gas, and forms a thin zirconium nitride nucleation layer by reverse sputtering at the fourth reverse sputtering power; 6 at the fifth sputtering power Next, DC magnetron sputtering is used to deposit and grow a thin zirconium nitride barrier layer; 7, the sputtering gas is fed, and the metal zirconium film is deposited by radio frequency magnetron sputtering under the sixth sputtering power; 8, the gas is stopped, and the metal High-temperature annealing of the zirconium thin film; 9 lowering the temperature of the silicon substrate to room temperature. The method can realize the single preferred orientation and high crystal quality preparation of the metal zirconium thin film on the silicon substrate.

Description

technical field [0001] The invention belongs to the technical field of semiconductor and thin film material preparation, in particular to a method for preparing a metal zirconium thin film on a silicon substrate by magnetron sputtering. Background technique [0002] Transition group refractory metals (including: titanium (α-Ti), (α-Zr), hafnium (α-Hf)) usually have a hexagonal crystal structure, which not only has good thermal and chemical stability, but also has good electrical conductivity . In the field of semiconductor technology, especially silicon-based device technology, transition family refractory metal thin film materials have extremely important application value. For example, the magnetron sputtering and electron beam evaporation preparation process of α-Ti film is relatively mature, and it is a commonly used ohmic contact metal electrode material in silicon-based microelectronic device technology and power electronic device technology; α-Zr and α-Hf thin film a...

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Problems solved by technology

Among them, the growth rate of ALD materials is slow. Although high-purity metal zirconium films with nanoscale thickness can be prepared, due to the low growth temperature, only amorphous or polycrystalline materials with poor crystal quality can be grown.

However, the preparation and growth of α-Zr thin films by MOCVD is still in research and development, and there is no research report on the growth of α-Zr with a single preferred orientation and high crystal quality on Si substrates.

The Institute of Semiconductors of the Chinese Academy of Sciences has used the ion beam epitaxy (IBE) process to grow α-Zr thin films with a single preferred orientation. However, due to the small film formation area (2cm×2cm) of the ion beam epitaxy process, it is not suitable for the use of existing semiconductor devices. process device

It is also difficult to grow metal zirconium thin films by electron beam evaporation, but it is difficult to achieve high crystal quality growth with a single preferred orientation of α-Zr. In most cases, only polycrystalline thin films with disordered orientation and large surface fluctuations can be obtained.

At present, magnetron sputtering is still the main process for preparing and growing α-Zr thin films, but most of the existing research results are either because the residual oxide layer on the surface of the Si substrate is not completely removed, which is not conducive to the nucleation and high-quality crystal growth of α-Zr, Either because the substrate heating temperature is relatively low or the sputtering power is relatively high, most of them have not achieved the growth of α-Zr thin film with a single preferred orientation and high crystal quality on the Si substrate. If the growth temperature is high or the sputtering power is high, it will also cause metal The surface of zirconium and silicon are intermixed, and metal silicides (such as Zr x Si y ), most research results only obtained α-Zr polycrystalline films with disordered orientation. The height width (FWHM) drops below 5°, and the surface relief is also large (AFM surface roughness (RMS) is higher than 3nm)

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