Method for preparing self-aligned nickel silicide

Abstract

The invention provides a method for preparing self-aligned nickel silicide, which at least comprises the following steps of precleaning exposed a silicon surface to remove native oxides; depositing nickel or nickel alloy on the cleaned silicon surface; performing the low-temperature fast thermal annealing treatment at a first temperature under a specific gas atmosphere (pure inert gases with a flow rate of 0-5 slm), and enabling part of the nickel or the nickel alloy to react with silicon so as to form a high-resistance silicon nickel compound; removing the unreacted nickel or nickel alloy; performing the high-temperature fast thermal annealing treatment at a second temperature under the specific gas atmosphere (pure inert gases with a flow rate of 0-5 slm), and converting the high-resistance silicon nickel compound into a low-resistance silicon nickel compound. According to the method for preparing the self-aligned nickel silicide, the flow rate of the inert gases in the fast thermal annealing treatment is reduced, so that the content of oxidized impurities in the inert gases is reduced, the production quality of nickel silicide is improved, the probability of generating spiking defects and piping defects due to the fact that nickel atoms diffuse along the defects is reduced by means of reducing the pressure in a chamber body, and meanwhile the production cost is lowered.

Description

technical field [0001] The invention relates to a semiconductor manufacturing process, in particular to a method for preparing self-aligned nickel silicide. Background technique [0002] With the continuous improvement of the manufacturing process of semiconductor devices, the current mainstream silicon chip manufacturing size has reached 300mm, and the mainstream technology node has also entered the 45nm process, and is moving towards the more advanced 28 / 20nm process. [0003] In the process of 45nm and below, nickel silicide has replaced traditional titanium silicide and cobalt silicide as the standard contact material for source / drain / gate contact holes. Compared with traditional silicides, nickel silicides have the advantages of low resistance, low stress, and low loss of silicon raw materials. However, the biggest disadvantage of nickel silicide is poor growth thermal stability, which puts high demands on each process link in the entire growth process. Once the proces...

AI Technical Summary

Problems solved by technology

The greater the flow rate of the inert gas in the annealing process, the higher the content of oxidized impurities, the greater the pressure in the chamber, and the greater the possibility of nickel atoms diffusing along the defects to produce spiking defects and piping defects Large, not only affects the formation and quality of nickel silicide, but also increases the production cost

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