Ta-Al-N diffusion blocking layer thin film for copper wiring and preparation thereof

Abstract

The invention discloses a film for a Ta-Al-N dispersing obstructing layer used for interconnection of copper, which is characterized in that the weight percentage of the film is 1.5 to 7.8 percent of Al, 8.4 to 11.5 percent of N and the rest is Ta; the film is manufactured by using a multi-target magnetic control sputtering method. The invention also discloses a technique for preparing the film for the Ta-Al-N dispersing obstructing layer, in particular preparation by adopting the magnetic control sputtering method. The obstructing characteristics of the Ta-Al-N film can not lose effect until being annealed for 5 minutes under the temperature of 900 DEG C. compared with the traditional Ta-N or Ta / Ta-N obstructing layer, the Ta-Al-N film of the invention can effectively improve the obstructing property thereof simultaneously when maintaining the excellent adhesive property and low resistance rate of the traditional material of the obstructing layer as a few amount of Al is added; simultaneously as the existence of the few amount of Al, an ultra-thin alumina layer is easy to be formed on the film surface, thus effectively avoiding the obstructing layer from being oxidized.

Description

technical field [0001] The present invention relates to a copper interconnection barrier layer Ta-Al-N thin film coating process applied in the field of new generation integrated circuit technology, specifically a Ta-Al-N diffusion barrier layer thin film for copper interconnection and its preparation craft. Background technique [0002] With the development of very large scale integrated circuits, RC delay and crosstalk between metal interconnections of integrated circuits are replacing gate delays to become the main factors restricting the further improvement of integrated circuit speed. Adopt Cu / low K dielectric to replace traditional Al / SiO 2 The system can greatly improve the performance of integrated circuits. However, because Cu diffuses very quickly in Si and its oxides and most of the media, and once Cu enters the device structure, it will form deep-level impurities, which have a strong trap effect on the carriers in the device and degrade the device performance. ...

AI Technical Summary

Problems solved by technology

However, with the development of integrated circuits to the sub-micron level, the requirements for the barrier layer are getting higher and higher. People began to turn their attention to the ternary amorphous film of Ta (Ti, Zr, W), N, Si. The crystallization temperature is very high, and there are fewer grain boundaries and defects, which can more effectively block the diffusion of Cu atoms, but its barrier performance needs to be further improved