Method for lowering resistance value of cobalt disilicide layer of semiconductor devices

Abstract

In the invention, first a layer of metal cobalt is formed on silicon substrate. Next, two times of annealing treatment are carried out. First annealing treatment turns layer of metal cobalt to layer of cobalt silicide (CoSi). Then, a covering layer in thickness of 1000-3000 Angstrom is formed to cover the layer of metal cobalt in order to restrain regrowth of crystal grain of cobalt silicide in following procedure. Finally, second annealing treatment is carried out to turn the layer of cobalt silicide to layer of disilcobalt (CoSi2).

Description

technical field [0001] The invention relates to a manufacturing method of a semiconductor component, and in particular to a method capable of reducing the resistance value of a cobalt disilicide (CoSi2) layer in the component. Background technique [0002] In the process of semiconductor components, a low-resistance cobalt disilicide (CoSi2) layer is often formed on internal electrical connection points such as gate, source or drain. Generally speaking, the manufacturing method of cobalt disilicide is to first form a metal cobalt (Co) layer on a silicon-containing substrate, and then undergo two annealing treatments (annealing treatment) to transform the cobalt into cobalt disilicide. Wherein, the first annealing treatment is to diffuse cobalt into the silicon-containing substrate to form a cobalt silicide (CoSi) layer. The second annealing treatment is to transform the cobalt silicide layer into low-resistance cobalt disilicide, so as to reduce the resistance value of the ...

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Problems solved by technology

Furthermore, if the large grains 232 of cobalt disilicide pass through the source / drain region 12 and contact the silicon substrate 10, when a voltage is applied to the semiconductor device, leakage current will also be caused.

In addition, the discontinuous region 231 produced by grain re-growth will increase the resistance value of the cobalt disilicide layer 23, which will affect the performance of the component.

The above-mentioned defects will become more serious after the cobalt disilicide layer 23 undergoes a series of subsequent high-temperature annealing treatments.

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