US 6,147,005 A · Method of forming dual damascene structures

Abstract

A method for forming the dual damascene structure over a semiconductor substrate is disclosed in the present invention. First, a first dielectric layer is formed on the semiconductor substrate. An etch stopping layer is formed on the first dielectric layer. And a second dielectric layer is formed on the etch stopping layer. The second dielectric layer is then etched till the etch stopping layer to form a first opening and a second opening on the second dielectric layer. It is noted that the size of the second opening is bigger than that of the first opening. A polymer layer is next formed on the second dielectric layer and the etch stopping layer to close the first opening and to fill into a portion of the second opening for defining a third opening in the second opening. The polymer layer formed on the bottom of the third opening, the etch stopping layer and the first dielectric layer are etched in sequence, by using the polymer layer formed on the sidewalls of the second opening to serve as an etching mask, to expose a surface of the semiconductor substrate for defining the third opening on the first dielectric layer. After the polymer layer is removed, a conducting layer is fill into the first opening, the second opening and the third opening.

Claims22

Dependent claims

A method of forming the dual damascene structure over a semiconductor substrate, said method comprises the following steps of:

forming a first dielectric layer on said semiconductor substrate;
forming an etch stopping layer on said first dielectric layer;
forming a second dielectric layer on said etch stopping layer;
etching said second dielectric layer till said etch stopping layer to form a first opening and a second opening on said second dielectric layer, wherein a size of said second opening is bigger than that of said first opening;
forming a polymer layer on said second dielectric layer and said etch stopping layer for closing said first opening and filling into a portion of said second opening to define a third opening in said second opening;
etching said polymer layer formed on the bottom of said third opening, said etch stopping layer and said first dielectric layer to expose a surface of said semiconductor substrate for defining said third opening on said first dielectric layer by using said polymer layer formed on the sidewalls of said second opening to serve as an etching mask;
removing said polymer layer;
and
forming a conducting layer to fill into said first opening, said second opening and said third opening.

6 more elements

Dependencies are inferred from the claim text.

Method of forming dual damascene structures

Life of this patent

Method of forming dual damascene structures

Life of this patent

Abstract

Claims22