Dry etching preparation method of T-shaped hole of integrated circuit

Abstract

The invention provides a dry etching preparation method of a T-shaped hole of an integrated circuit. The method comprises the following steps: (1) manufacturing of a micropore etching window, carrying out primary photoetching on an isolation medium layer for metal interconnection and manufacturing the micropore etching window; (2) primary etching, carrying out micropore primary etching by an anisotropic plasma dry etching process, wherein the micropore depth after primary etching is smaller than the thickness of the isolation medium layer; and the difference between the thickness of the isolation medium layer and the depth of a micropore after primary etching is equal to the thickness of a macropore of the T-shaped hole; (3) manufacturing of a macropore etching window, carrying out degumming by a plasma dry degumming technology to form a macropore etching window; (4) secondary etching, carrying out secondary etching by the etching technology same as that in the step (2), wherein the secondary etching time is shorter than the primary etching time; and (5) degumming, removing a photoresist by the plasma dry degumming technology. The preparation method is simple; and etching of the T-shaped hole can be finished only by one piece of etching equipment, so that the production cost is reduced.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an etching preparation process for T-shaped holes in integrated circuit manufacturing. Background technique [0002] In integrated circuit manufacturing, as the size of the device decreases, the size of the lead hole in the back-end process also decreases, but the thickness of the dielectric does not become thinner, forming a lead hole with a high aspect ratio. As a result, the metal is difficult to fill in the lead hole, forming a void. cause device reliability problems. In order to solve this problem, the contact hole of the metal interconnection generally adopts a "T" structure at present. At present, there are two methods for making T-shaped holes. The first one is to use an isotropic etching machine or chamber for wet etching to etch a "bowl"-shaped hole; The etching machine or cavity of the opposite sex is used for etching, and the straight holes are etched. D...

AI Technical Summary

Problems solved by technology

For semiconductor manufacturing companies, it is very expensive to purchase equipment or increase the cavity, which increases the cost of the company

This processing method is generally used for 0.6um process platform, and it is not applicable for thinner line width

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