Method for manufacturing contact plug

Abstract

The invention provides a method for manufacturing a contact plug. The method comprises the following steps of: providing a semiconductor substrate on which a grid structure and a first interlamination medium layer are formed, wherein the grid structure is flushed with the first interlamination medium layer, and a source and a drain are formed in the semiconductor substrate on two sides of the grid structure; etching the first interlamination medium layer to form a first contact hole which is used for exposing the source and the drain; filling a first metal layer into the first contact hole; forming a second interlamination medium layer on the first interlamination medium layer; etching the second interlamination medium layer to form a second contact hole, wherein the position of the second contact hole corresponds to the position of the first contact hole; and filling a second metal layer into the second contact hole, wherein the resistivity of the second metal layer is smaller than that of the first metal layer; and the second metal layer in the second contact hole and the first metal layer in the first contact hole form the contact plug together. The contact plug manufactured by using the method has small resistance.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for manufacturing a contact plug. Background technique [0002] With the continuous development and progress of semiconductor manufacturing technology and related supporting technologies, the number of devices integrated on a unit area is increasing, and the integration degree of integrated circuits is getting higher and higher. The gap between the gates of adjacent devices becomes Smaller and smaller, which increases the difficulty of device manufacturing. For example, the process of fabricating contact plugs connecting source / drain electrodes and upper metal lines on both sides of gates of adjacent devices becomes more difficult. [0003] Specifically, please refer to Figure 1 to Figure 3 , is a schematic cross-sectional flow chart of a method for manufacturing a contact plug in the prior art. [0004] First, refer to figure 1 , providing a semiconductor su...

AI Technical Summary

Problems solved by technology

However, as the size of the first contact hole decreases, the contact plug resistance of the device becomes larger, which affects the response speed of the device

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