Method for forming contact plug

Abstract

Disclosed is a method for forming a contact plug. The method comprises that a substrate is provided, the substrate is provided with a source region and a drain region, a gate structure is formed on the substrate, the source region and the drain region are located at positions of the two sides of the gate structure, the gate structure comprises a side wall and a grid, a metal silicide is formed on the source region and the drain region of the substrate, a conducting layer of a predetermined thickness is formed on the metal silicide through an electroless plating method, an interlayer dielectric layer is formed, the conducting layer and the gate structure are covered, a contact hole is formed in the interlayer dielectric layer, the conducting layer is exposed, a conducting material is filled in the contact hole and the contact plug is formed. By the aid of the technical scheme, the problem of communication caused by gaps of two adjacent contact plugs is solved. Besides, the problems that contact resistance is increased due to the loss in metal silicide etching and the contact hole is not opened completely are solved or reduced at least.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for forming a contact plug. Background technique [0002] Figure 1 to Figure 4 It is a schematic cross-sectional structure diagram of a method for forming a contact plug in the prior art, referring to Figure 1 to Figure 4 , the method of forming the contact plug in the prior art is: refer to figure 1 , providing a semiconductor substrate 10, forming an active region, a drain region and a channel region (not shown in the figure) in the semiconductor substrate 10, forming a gate dielectric layer 11, a gate 12 and side electrodes on the semiconductor substrate 10. The grid structure of the wall 13. After the gate structure is formed, metal silicide (Silicide) 14, such as nickel silicide (NiSi), is usually formed on the surface of the source region, the drain region, and the polysilicon gate to reduce the contact between the plug and the source region, the drain r...

AI Technical Summary

Problems solved by technology

[0005] The problem to be solved by the present invention is that the method for forming contact plugs in the prior art is easy to form gaps in the interlayer dielectric layer, resulting in the conduction of adjacent contact plugs and the loss of metal silicide, resulting in increased contact resistance; the aspect ratio of the contact hole High causes the contact hole not to fully open

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