Plasma treatment for copper oxide reduction

• US 6,946,401 B2
• Filed: 09/04/2003
• Issued: 09/20/2005
• Est. Priority Date: 11/17/1998
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Huang, Judy H., Rathi, Sudha, Kim, Bok Hoen, Bencher, Christopher Dennis, Ngai, Christopher S.
• Primary Examiner(s): Pham, Long
• Application Number:
  US10/655,438
• Publication Number:
  US 20040046260A1
• Time in Patent Office: 747 Days
• Field of Search: 438/706, 438/573, 438/675, 438/680, 438/597, 438/676, 438/685, 438/656, 438/694
• US Class Current: 438/706
• CPC Class Codes: B08B 7/0035 by radiant energy, e.g. UV, laser, light beam or the like
• CPC Class Codes: C23C 16/0245 by etching with a plasma
• CPC Class Codes: C23G 5/00 Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
• CPC Class Codes: H01L 21/02063 the processing being the formation of vias or contact holes
• CPC Class Codes: H01L 21/02068 during, before or after processing of conductive layers, e.g. polysilicon or amorphous silicon layers
• CPC Class Codes: H01L 21/02071 the processing being a delineation, e.g. RIE, of conductive layers
• CPC Class Codes: H01L 21/02074 the processing being a planarization of conductive layers
• CPC Class Codes: H01L 21/02115 the material being carbon, e.g. alpha-C, diamond or hydrogen doped carbon
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02167 the material being a silicon carbide not containing oxygen, e.g. SiC, SiC:H or silicon carbonitrides H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/3148 Silicon Carbide layers
• CPC Class Codes: H01L 21/3185 of siliconnitrides
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 21/76877 : Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76883 : Post-treatment or after-treatment of the conductive material
• CPC Class Codes: H01L 23/53238 : Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 : Impedance

Abstract

The present invention provides an in situ plasma reducing process to reduce oxides or other contaminants, using a compound of nitrogen and hydrogen, typically ammonia, at relatively low temperatures prior to depositing a subsequent layer thereon. The adhesion characteristics of the layers are improved and oxygen presence is reduced compared to the typical physical sputter cleaning process of an oxide layer. This process may be particularly useful for the complex requirements of a dual damascene structure, especially with copper applications.

Claims

1. A method for reducing oxidation of an interface of a semiconductor device, said semiconductor device having at least a first layer comprising silicon carbide and a second layer wherein the interface is disposed between said first and second layers, the method comprising the steps of:

(a) providing said first layer having a partially oxidized interface;

(b) introducing a hydrogen-containing plasma to said interface;

(c) chemically reducing the oxidized portion of the interface; and

(d) introducing second-layer-forming materials to said hydrogen-containing plasma.

2. The method of claim 1 wherein the second layer comprises at least one layer selected from the group consisting of a patterned etch stop layer, a barrier layer, and a film comprising silicon carbide.

3. The method of claim 1 wherein the first layer further comprises at least one conductive device disposed therein.

4. The method of claim 3 wherein the at least one conductive device is formed from at least one of copper, titanium, tantalum, and tungsten.

5. The method of claim 1 wherein the hydrogen-containing plasma further comprises ammonia.

6. The method of claim 1 wherein the hydrogen-containing plasma further comprises silane.

7. A method for reducing oxidation of an interface of a semiconductor device, said semiconductor device having at least a first layer comprising silicon carbide and having one or more conductive material devices disposed therein and a second layer wherein the interface is disposed between said first and second layers, the method comprising the steps of:

(a) providing said first layer having oxidized conductive material at said interface;

(b) introducing an ammonia/nitrogen plasma to said interface; and

(c) introducing silane to said ammonia/nitrogen plasma.

8. The method of claim 7 wherein the second layer comprises at least one layer selected from the group consisting of a patterned etch stop layer, a barrier layer, and a film comprising silicon carbide.

9. A method of removing a contaminant from one or more conductive pathways disposed in a layer comprising silicon carbide on a substrate, comprising:

(a) introducing a reducing agent comprising nitrogen and hydrogen into a process chamber;

(b) initiating a plasma of the reducing agent in the process chamber; and

(c) exposing the contaminant to the plasma of reducing agent.

10. The method of claim 9 further comprising:

depositing in-situ a silicon carbide film after the exposing step without breaking vacuum in the process chamber.

11. The method of claim 9 wherein the contaminant comprises oxide of at least one material contained in at least one layer that has been formed on the substrate or contained in reactants used to form the at least one layer.

12. The method of claim 9 wherein the reducing agent further comprises ammonia.

13. The method of claim 9 wherein the reducing agent comprises silane.