Method for cleaning substrate

• US 10,020,184 B2
• Filed: 03/09/2017
• Issued: 07/10/2018
• Est. Priority Date: 06/29/2015
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Hong, Shih-Ping, Liu, Yu-Cheng
• Primary Examiner(s): Nicely, Joseph C
• Application Number:
  US15/454,134
• Publication Number:
  US 20170178895A1
• Time in Patent Office: 488 Days
• CPC Class Codes: B08B 7/0035 by radiant energy, e.g. UV, laser, light beam or the like
• CPC Class Codes: B08B 9/0865 by burning-out B08B9/40 takes precedence
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: H01J 2237/334 Etching
• CPC Class Codes: H01J 2237/335 Cleaning
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32834 Exhausting
• CPC Class Codes: H01J 37/32853 Hygiene
• CPC Class Codes: H01J 37/32862 In situ cleaning of vessels and/or internal parts
• CPC Class Codes: H01J 37/32871 Means for trapping or directing unwanted particles
• CPC Class Codes: H01L 21/02041 Cleaning
• CPC Class Codes: H01L 21/0206 during, before or after processing of insulating layers
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/02071 the processing being a delineation, e.g. RIE, of conductive layers
• CPC Class Codes: H01L 21/02334 in-situ cleaning after layer formation, e.g. removing process residues
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31122 of layers not containing Si, e.g. PZT, Al2O3
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/76802 : by forming openings in dielectrics
• CPC Class Codes: H01L 21/76814 : post-treatment or after-treatment, e.g. cleaning or removal of oxides on underlying conductors

Abstract

A method for cleaning a substrate is provided. The method includes providing a substrate. Metal compound residues are formed over the substrate. The method includes exposing the substrate to an organic plasma to volatilize the metal compound residues. The organic plasma is generated from a gas. The gas includes an organic gas, and the organic gas is made of a hydrocarbon compound or an alcohol compound.

Claims

1. A method for cleaning a substrate, comprising:

providing a substrate;

depositing an etch stop layer over the substrate, wherein the etch stop layer comprises a metal compound;

depositing a dielectric layer over the etch stop layer;

performing a plasma etching process to remove a first portion of the dielectric layer and a second portion of the etch stop layer, wherein metal compound residues are formed from the second portion and formed over at least one of the dielectric layer or the etch stop layer, the plasma etching process forms an opening in the dielectric layer and a recess in the etch stop layer, and the opening is over the recess; and

exposing the substrate to an organic plasma to volatilize the metal compound residues, wherein the organic plasma removes the etch stop layer exposed by the opening.

2. The method for cleaning a substrate as claimed in claim 1, wherein the plasma etching process comprises a fluorine-containing plasma etching process.

3. The method for cleaning a substrate as claimed in claim 1, further comprising:

after the volatilization of the metal compound residues, exposing the substrate to an oxygen atom-containing plasma to volatilize organic compound residues formed over the substrate.

4. The method for cleaning a substrate as claimed in claim 1, wherein the organic plasma is generated from a gas, the gas comprises an organic gas, and the organic gas is made of a hydrocarbon compound or an alcohol compound.

5. The method for cleaning a substrate as claimed in claim 4, wherein the hydrocarbon compound comprises alkane, alkene, or alkyne, and the alcohol compound comprises CH₃OH, C₂H₅OH, or C₃H₇OH.

6. The method for cleaning a substrate as claimed in claim 5, wherein the gas further comprises a chain termination gas, and the chain termination gas is made of hydrogen, carbon oxide, carbon dioxide, oxygen, or a combination thereof.

7. A method for cleaning a substrate, comprising:

providing a plasma processing apparatus comprising a housing, an upper electrode plate, a lower electrode pedestal, and a gas exhaust unit, wherein a plasma processing chamber is in the housing, the upper electrode plate and the lower electrode pedestal are in the plasma processing chamber, the housing has a gas outlet, and the gas exhaust unit is connected to the gas outlet;

providing a substrate in the plasma processing chamber and over the lower electrode pedestal;

forming a metal compound layer over the substrate;

performing a plasma etching process to remove a portion of the metal compound layer, wherein during the plasma etching process, metal compound residues are formed over the substrate;

exposing the substrate to an organic plasma to volatilize the metal compound residues into a gaseous metal compound; and

exhausting the gaseous metal compound from the plasma processing chamber using the gas exhaust unit.

8. The method for cleaning a substrate as claimed in claim 7, wherein the gaseous metal compound comprises metal organics.

9. The method for cleaning a substrate as claimed in claim 8, wherein the metal organics comprise an alkyl metal compound, an alkoxy metal compound, an alkoxy alkyl metal compound, or a combination thereof.

10. The method for cleaning a substrate as claimed in claim 9, wherein the metal organics comprise aluminum, gallium, indium, or titanium.

11. The method for cleaning a substrate as claimed in claim 7, wherein the metal compound residues are in a solid state.

12. The method for cleaning a substrate as claimed in claim 11, wherein the metal compound residues are made of a Group III-A metal fluoride, a Group III-A metal oxide, a Group III-A metal nitride, a Group IV-B metal fluoride, a Group IV-B metal oxide, or a Group IV-B metal nitride.

13. The method for cleaning a substrate as claimed in claim 7, wherein the organic plasma is generated from a gas, the gas comprises an organic gas, and the organic gas is made of a hydrocarbon compound or an alcohol compound.

14. The method for cleaning a substrate as claimed in claim 13, wherein the hydrocarbon compound comprises alkane, alkene, or alkyne.

15. The method for cleaning a substrate as claimed in claim 13, wherein the alcohol compound comprises CH₃OH, C₂H₅OH, or C₃H₇OH.

16. A method for cleaning a substrate, comprising:

forming a metal compound layer over a substrate;

performing a plasma etching process to remove a portion of the metal compound layer, wherein during the plasma etching process, metal compound residues are formed over the metal compound layer; and

exposing the metal compound layer to an organic plasma to volatilize the metal compound residues into a gaseous metal compound.

17. The method for cleaning a substrate as claimed in claim 16, wherein the plasma etching process comprises a fluorine-containing plasma etching process.

18. The method for cleaning a substrate as claimed in claim 16, further comprising:

after the volatilization of the metal compound residues, exposing the metal compound layer to an oxygen atom-containing plasma to volatilize organic compound residues formed over the metal compound layer.

19. The method for cleaning a substrate as claimed in claim 16, wherein the organic plasma is generated from a gas, the gas comprises an organic gas, and the organic gas is made of a hydrocarbon compound or an alcohol compound.

20. The method for cleaning a substrate as claimed in claim 19, wherein the hydrocarbon compound comprises alkane, alkene, or alkyne, and the alcohol compound comprises CH₃OH, C₂H₅OH, or C₃H₇OH.