Method of forming a conformal spacer adjacent to a gate electrode structure
First Claim
Patent Images
1. A method of forming spacer elements, the method comprising:
- forming a conductive line above a semiconductor region;
conformally forming a spacer layer stack over said conductive line and said semiconductor region, said spacer layer stack comprising an etch stop layer separating a first spacer layer from a second spacer layer formed above said first spacer layer, said first and second spacer layers comprised of a material that may be etched selectively to said etch stop layer by a predefined etch chemistry;
anisotropically etching said second spacer layer to form sacrificial sidewall spacers;
removing portions of said etch stop layer that are exposed during the formation of said sacrificial sidewall spacers; and
removing said sacrificial sidewall spacers and exposed portions of said first spacer layer by an etch process using said specified etch chemistry to form said spacer elements, wherein the steps of anisotropically etching said second spacer layer to form sacrificial sidewall spacers, removing portions of said etch stop layer that are exposed during the formation of said sacrificial sidewall spacers, and removing said sacrificial sidewall spacers and exposed portions of said first spacer layer by a common etch process using said specified etch chemistry are all performed in a single etch chamber as an in situ process.
1 Assignment
0 Petitions
Accused Products
Abstract
In a process for forming L-shaped sidewall spacers for a conducive line element, such as a gate electrode structure, the sacrificial spacers are formed of a material having a similar etch behavior as the material of the finally obtained L-shaped spacer, thereby improving tool utilization and reducing process complexity compared to conventional processes. In one particular embodiment, a spacer layer stack is provided having a first etch stop layer, a first spacer layer, a second etch stop layer, and a second spacer layer, wherein the first and second spacer layers are comprised of silicon nitride.
41 Citations
32 Claims
-
1. A method of forming spacer elements, the method comprising:
-
forming a conductive line above a semiconductor region; conformally forming a spacer layer stack over said conductive line and said semiconductor region, said spacer layer stack comprising an etch stop layer separating a first spacer layer from a second spacer layer formed above said first spacer layer, said first and second spacer layers comprised of a material that may be etched selectively to said etch stop layer by a predefined etch chemistry; anisotropically etching said second spacer layer to form sacrificial sidewall spacers; removing portions of said etch stop layer that are exposed during the formation of said sacrificial sidewall spacers; and removing said sacrificial sidewall spacers and exposed portions of said first spacer layer by an etch process using said specified etch chemistry to form said spacer elements, wherein the steps of anisotropically etching said second spacer layer to form sacrificial sidewall spacers, removing portions of said etch stop layer that are exposed during the formation of said sacrificial sidewall spacers, and removing said sacrificial sidewall spacers and exposed portions of said first spacer layer by a common etch process using said specified etch chemistry are all performed in a single etch chamber as an in situ process. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
-
19. A method of forming spacer elements, the method comprising:
-
forming a conductive line above a semiconductor region; forming a spacer layer stack comprising a first etch stop layer formed of a first material, a first spacer layer formed of a second material, a second etch stop layer formed of said first material and a second spacer layer formed of said second material; forming a sacrificial spacer at least from said second spacer layer; and forming spacer elements at least from said first spacer layer by removing said sacrificial spacer, wherein the steps of forming sacrificial sidewall spacers and forming said conformal spacer elements by removing said sacrificial sidewall spacers are all performed in a single etch chamber as an in situ etch process. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
-
Specification