Interconnection process of metalized Mo, Si-Al double-layer structure of integrated circuits

Abstract

The invention relates to an interconnection process of a metalized Mo, Si-Al double-layer structure of integrated circuits. The process has the following process flows: putting a wafer which is to be treated as metal in a sputtering device; under high vacuum conditions, sputtering barrier metal Mo with the thickness ranging between 900 and 1,100 firstly, then sputtering metal Al with the thickness ranging between 10,000 and 20,000 and adopting an aluminum alloy target containing 1 to 2 percent of Si as a sputtering source; and taking out the wafer from a vacuum chamber after sputtering. The interconnection process is characterized in that a layer of the barrier metal Mo is added between an aluminum layer and a silicon layer to prevent generation of alloy points; meanwhile, the aluminum alloy target which has a lower melting point and contains 1 to 2 percent of the Si is taken as the sputtering source so as to obtain low-contact resistance at the lower temperature and further prevent the generation of the alloy points; and the main function of containing the silicon is to improve ohmic contact characteristics of an alloy layer and ensure that the aluminum alloy is more inclined to react with the silicon in the alloy during processing of contact heating, thereby greatly increasing final test yield and improving reliability of finished circuits finally.

Description

technical field [0001] The invention relates to a process for realizing metal interconnection in the metallization process in the manufacture of integrated circuits, in particular to an integrated circuit metallization Mo, Si-Al two-layer structure with low contact resistance and high reliable contact quality as the process improvement direction interconnection process. Background technique [0002] The current metallization process of integrated circuits uses aluminum source to realize the interconnection of contact holes of various components in the chip by means of sputtering or evaporation. The contact hole is a high impurity concentration region (P+ or n+) formed through multiple diffusion processes. The P+ or n+ region and aluminum form a low-resistance ohmic contact through an alloy. Aluminum interconnects have the advantages of relatively low resistivity and easy etching, and are widely used in the early stages of large and medium-scale integrated circuit manufactu...

AI Technical Summary

Problems solved by technology

Aluminum-silicon contacts through a certain temperature alloy, and alloy points are easily formed at the defects. Because the diffusion mechanism at these alloy points is different from other places, the diffusion speed is particularly fast, and the pn junction surface is not flat, resulting in low breakdown and segmental breakdown Even punch through, so that the yield rate is seriously affected

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