Sidewall protection scheme for contact formation

Patent metadata

Field	Value
Publication number	US-2016379870-A1
Application number	US-201615191912-A
Country	US
Kind code	A1
Filing date	Jun 24, 2016
Priority date	Jun 24, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

Method of manufacturing a semiconductor device is described that uses sidewall protection of a recessed feature to prevent loss of critical dimension during a cleaning process to remove etch residue. According to one embodiment, the method includes providing a substrate containing a film thereon having a recessed feature with a sidewall and a bottom portion, depositing a conformal film on the sidewall and on the bottom portion, removing the conformal film from the bottom portion in an anisotropic etching process, where the remaining conformal film forms a protection film on the sidewall, and performing a cleaning process that removes etch residue from the recessed feature without etching the protection film or the sidewall.

First claim

What is claimed is:

1 . A substrate processing method, comprising:
providing a substrate containing a film thereon having a recessed feature with a sidewall and a bottom portion; depositing a conformal film on the sidewall and on the bottom portion; removing the conformal film from the bottom portion in an anisotropic etching process, wherein the remaining conformal film forms a protection film on the sidewall; and performing a cleaning process that removes etch residue from the bottom portion without etching the protection film or the sidewall.

2 . The method of claim 1 , further comprising following the cleaning process, performing an isotropic etching process to form a contact region below the protection film, the contact region having a width that is greater than a width of the recessed feature.

3 . The method of claim 1 , wherein the cleaning process further etches the bottom portion to form a cavity below the protection film.

4 . The method of claim 1 , wherein an etch stop layer forms the bottom portion of the recessed feature.

5 . The method of claim 4 , further comprising etching through the etch stop layer prior to performing the cleaning process to remove the residue.

6 . The method of claim 4 , further comprising etching through the etch stop layer after performing the cleaning process to remove the residue.

7 . The method of claim 1 , wherein the conformal film includes a metal oxide film that is selected from the group consisting of HfO 2 , ZrO 2 , TiO 2 , Al 2 O 3 , and a combination thereof.

8 . The method of claim 1 , wherein the conformal film is selected from the group consisting of a metal oxide film, a metal nitride film, a metal oxynitride film, a metal silicate film, and a combination thereof

9 . The method of claim 1 , wherein the conformal film has a thickness of about 4 nm or less.

10 . The method of claim 1 , wherein the cleaning process includes a wet cleaning process that uses aqueous HCl, aqueous H 2 O 2 , aqueous HF, aqueous NH 4 OH, aqueous H 3 PO 4 , aqueous H 2 SO 4 , or a combination thereof.

11 . The method of claim 1 , wherein the cleaning process includes a dry etching process that includes exposing the substrate to a gas containing HF, NH 3 , H 2 O 2 , a halogen-containing gas, or a combination thereof.

12 . The method of claim 1 , wherein the cleaning process includes a chemical oxide removal (COR) process that removes silicon and oxygen.

13 . The method of claim 1 , wherein depositing the conformal film includes atomic layer deposition (ALD).

14 . A substrate processing method, comprising:
providing a substrate containing a film thereon having a recessed feature with a sidewall and an etch stop layer forming a bottom portion of the recessed feature; depositing a conformal metal oxide film by atomic layer deposition (ALD) on the sidewall and on the bottom portion; removing the conformal metal oxide film from the bottom portion in an anisotropic etching process, wherein the remaining conformal metal oxide film forms a protection film on the sidewall; and performing a cleaning process that removes etch residue from the recessed feature without etching the protection film or the sidewall.

15 . The method of claim 14 , further comprising
etching through the etch stop layer prior to performing the cleaning process to remove the residue.

16 . The method of claim 14 , further comprising
etching through the etch stop layer after performing the cleaning process to remove the residue.

17 . The method of claim 14 , wherein the metal oxide film is selected from the group consisting of HfO 2 , ZrO 2 , TiO 2 , Al 2 O 3 , and a combination thereof

18 . The method of claim 14 , wherein the cleaning process includes a wet cleaning process that uses aqueous HCl, aqueous H 2 O 2 , aqueous HF, aqueous NH 4 OH, aqueous H 3 PO 4 , aqueous H 2 SO 4 , or a combination thereof.

19 . The method of claim 14 , wherein the cleaning process includes a dry etching process that includes exposing the substrate to a gas containing HF, NH 3 , H 2 O 2 , a halogen-containing gas, or a combination thereof

20 . The method of claim 14 , wherein the protection film has a thickness of about 2 nm or less.

Assignees

• Tokyo Electron Ltd

Inventors

• Clark Robert D
• Tapily Kandabara N

Classifications

• H10P14/6339

  deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD · CPC title

• H10P70/234

  the processing being the formation of vias or contact holes · CPC title

• H10P50/695

  characterised by the process involved to create the mask, e.g. lift-off masks or sidewalls or to modify the mask · CPC title

• H10P50/642

  Chemical etching · CPC title

• H10P50/285

  of materials not containing Si, e.g. PZT or Al2O3 · CPC title