Method for preparing zirconium nitride thin film on silicon substrate by magnetron sputtering

Abstract

The invention provides a method for preparing a zirconium nitride film on a silicon substrate by magnetron sputtering, comprising: placing the cleaned silicon substrate and a metal zirconium target in a growth chamber under preset vacuum conditions; The surface of the silicon substrate is pretreated by baking and reverse sputtering dry cleaning at a preset temperature; the surface of the metal zirconium target is pretreated by radio frequency magnetron sputtering; the surface of the silicon substrate is prepared by the radio frequency magnetron sputtering process Deposit a metal zirconium layer on top; reduce the flow of argon gas and pass nitrogen gas into the growth chamber, and use the reverse sputtering process to nitride the deposited metal zirconium layer to form a zirconium nitride nucleation layer; use the DC magnetron sputtering process, in nitrogen A zirconium nitride film is deposited on the zirconium nucleation layer; the argon gas is turned off and the heating temperature of the substrate is raised to the preset annealing temperature, and the zirconium nitride film is annealed in a nitrogen atmosphere; the nitrogen pressure in the growth chamber is adjusted and controlled, The heating temperature of the substrate is lowered to room temperature according to a preset cooling rate to obtain a zirconium nitride thin film.

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 zirconium nitride thin film on a silicon substrate by magnetron sputtering. Background technique [0002] Transition group refractory metal nitrides (including: titanium nitride (TiN), zirconium nitride (ZrN), hafnium nitride (HfN)) usually have a cubic rock salt structure, which not only has good thermal and chemical stability, but also has good The electrical conductivity and resistivity are even comparable to some metal materials with good electrical conductivity. In the field of semiconductor technology, especially silicon-based device technology, transition group refractory metal nitride thin film materials have extremely important application value. For example, the magnetron sputtering and atomic layer deposition preparation process of TiN film is relatively mature, and it is the most commonly used interdif...

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Problems solved by technology

Among them, the growth rate of ALD materials is slow. Although high-purity ZrN 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 ZrN thin films by MOCVD is still in research and development, and there is no high-quality monolith that can achieve the X-ray rocking curve (XRC) half-maximum width (FWHM) of the ZrN (111) diffraction peak on Si substrates below 1°. Crystal thin film growth results report

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

Magnetron sputtering is still the main process for preparing and growing ZrN thin films, but most of the existing research results are not conducive to the formation of ZrN due to the incomplete removal of the residual oxide layer on the surface of the Si substrate or the avoidance of the nitriding of the Si substrate surface first. Nucleated and grown amorphous Si x N y layer, or due to the relatively low heating temperature of the substrate or the relatively high sputtering power, most of the ZrN thin films have not grown on the Si substrate with a single preferred orientation and high crystal quality, and most research results have only obtained ZrN polycrystalline thin films with disordered orientation, and Surface relief is also large (AFM surface roughness (RMS) higher than 3nm)

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