Reverse selective etch stop layer

Patent metadata

Field	Value
Publication number	US-2022181204-A1
Application number	US-202017110818-A
Country	US
Kind code	A1
Filing date	Dec 3, 2020
Priority date	Dec 3, 2020
Publication date	Jun 9, 2022
Grant date	—

Abstract

Methods and apparatus for forming a reverse selective etch stop layer are disclosed. Some embodiments of the disclosure provide interconnects with lower resistance than methods which utilize non-selective (e.g., blanket) etch stop layers. Some embodiments of the disclosure utilize reverse selective etch stop layers within a subtractive etch scheme. Some embodiments of the disclosure selectively deposit the etch stop layer by passivating the surface of the metal material.

First claim

What is claimed is:

1 . A method comprising:
selectively depositing an etch stop layer on a substrate surface comprising a first dielectric material with a plurality of feature formed therein and a first metal material within the features, the etch stop layer deposited on the surface of the first dielectric material over the surface of the first metal material; depositing a second metal material on the surface of the first metal material and the etch stop layer; and etching the second metal material to expose portions of the etch stop layer.

2 . The method of claim 1 , wherein the first dielectric material consists essentially of a low-k dielectric.

3 . The method of claim 1 , wherein the first metal material consists essentially of copper.

4 . The method of claim 1 , wherein the etch stop layer is deposited with a selectivity greater than or equal to 5.

5 . The method of claim 1 , wherein the first metal material and the second metal material are the same material.

6 . The method of claim 1 , wherein at least one feature is a via.

7 . The method of claim 1 , wherein the surface of the first metal material is coplanar with the surface of first dielectric material.

8 . The method of claim 1 , wherein the first metal material does not completely fill the features.

9 . The method of claim 8 , wherein the second metal material fills the features and is deposited on the top surface of the substrate.

10 . The method of claim 1 , wherein selectively depositing the etch stop layer comprises:
exposing the substrate to a blocking compound to form a passivated surface of the first metal material; and depositing the etch stop layer on the first dielectric material over the passivated surface of the first metal material.

11 . The method of claim 10 , wherein the blocking compound comprises one or more of a phosphoric acid, alkyl silane, halogenated silane, thiol or unsaturated hydrocarbon.

12 . The method of claim 10 , further comprising removing the blocking compound from the passivated surface of the first metal material before depositing the second metal material.

13 . The method of claim 12 , wherein the blocking compound is removed by exposing the substrate to a plasma comprising H 2 .

14 . The method of claim 1 , wherein the etch stop layer comprises tantalum nitride (TaN).

15 . The method of claim 1 , wherein etching the second metal material forms a conductive path between the first metal material within at least two of the features.

16 . The method of claim 1 , wherein etching the second metal material comprises a photolithography process.

17 . The method of claim 1 , further comprising removing the exposed portions of the etch stop layer.

18 . The method of claim 1 , wherein the resistance between the first metal material and the second metal material is less than the resistance of a similar device formed with a non-selective (blanket) etch stop layer.

19 . A method comprising:
exposing a substrate comprising a first dielectric material with a plurality of features formed therein and a first metal material within the features to a blocking compound to form a passivated surface of the first metal material; selectively depositing an etch stop layer on the first dielectric material over the passivated surface of the first metal material; removing the blocking compound from the surface of the first metal material; depositing a second metal material on the surface of the first metal material and the etch stop layer; etching the second metal material by photolithography to expose the etch stop layer and form a conductive path between the first metal material within at least two of the features; and removing exposed portions of the etch stop layer.

20 . A processing system comprising:
a central transfer station having a robot therein configured to move one or more substrate between chambers connected to the central transfer station; a first processing chamber connected to the central transfer station and configured to selectively deposit an etch stop layer on the substrate; a second processing chamber connected to the central transfer station and configured to deposit a metal material; a third processing chamber connected to the central transfer station and configured to etch metal materials; and a control system coupled to the central transfer station and the first, second, and third processing chambers, the control system comprising a first configuration to move the substrate between the first, second and third processing chambers, a second configuration to provide one or more process gases to the first processing chamber to selectively deposit the etch stop layer, a third configuration to provide one or more process gases to the second processing chamber to deposit the metal material, and a fourth configuration to provide one or more process gases to the third processing chamber to etch metal materials.

Assignees

• Applied Materials Inc

Inventors

• Kashefi Kevin
• Jansen Alexander
• Naik Mehul
• Ren He
• Chen Lu
• Chen Feng

Classifications

• H10W20/0633

  using subtractive patterning of the conductive members · CPC title

• H10W20/0693

  by forming self-aligned vias · CPC title

• H10P72/7602

  the wafers being placed on a robot blade or gripped by a gripper for conveyance · CPC title

• H10P72/0468

  comprising a chamber adapted to a particular process · CPC title

• H10P72/0454 Primary

  surrounding a central transfer chamber · CPC title