Methods of preventing oxidation of barrier metal of semiconductor devices

• US 20040137717A1
• Filed: 12/22/2003
• Published: 07/15/2004
• Est. Priority Date: 12/30/2002
• Status: Active Grant

• Current Assignee: DONGBU ELECTRONICS CO., LTD. (DB HiTek Co., Ltd.)
• Original Assignee: DONGBU ELECTRONICS CO., LTD. (DB HiTek Co., Ltd.)
• Inventors: Lee, Ki Min
• Granted Patent: US 6,962,877 B2
• Time in Patent Office: Days
• US Class Current: 438/631
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/7685 the layer covering a conductive structure H01L21/76849 takes precedence
• CPC Class Codes: H01L 2221/1078 Multiple stacked thin films not being formed in openings in dielectrics
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/53223 Additional layers associated with aluminium layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53266 Additional layers associated with refractory-metal 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

Abstract

A method for preventing oxidation of a barrier metal layer of a semiconductor device is disclosed. The method comprises the following steps. Ti/Ti_(1-x)Al_xN is deposited on the bottom and sidewalls of a via hole in a substrate by a plasma chemical vapor deposition to form a first barrier metal layer. The via hole is filled with a plug material and a planarization process is performed to form a via plug. A second barrier metal layer and a metal line are deposited in sequence on the substrate including the via plug. Then, Ti/Ti_(1-x)Al_xN as an ARC layer is deposited on the metal line by a plasma chemical vapor deposition. Accordingly, the present invention can improve device reliability by controlling continuous oxidation of the barrier metal layer using Ti_(1-x)Al_xN formed by addition of aluminum to TiN.

Claims

1. A method of preventing oxidation of a barrier metal of a semiconductor device, the method comprising:

forming a via hole in a substrate;

depositing Ti/Ti_(1-x)Al_xN as a first barrier metal layer on the bottom and sidewalls of the via hole by means of a plasma chemical vapor deposition;

filling the via hole with a plug material to form a via plug;

performing a planarization process to flatten the via plug;

depositing a second barrier metal layer and a metal line in sequence on the substrate including the via plug; and

depositing an ARC layer of Ti/Ti_(1-x)Al_xN on the metal line by means of a plasma chemical vapor deposition.

2. A method as defined by claim 1, wherein the second barrier metal layer comprises TiN or Ti/Ti_(1-x)Al_xN.

3. A method as defined by claim 2, wherein “

x”

in Ti_(1-x)Al_xN has a value between 0.5 and less than 1.

4. A method as defined by claim 1, wherein the plug material comprises tungsten or aluminum.

5. A method as defined by claim 1, wherein the plasma chemical vapor deposition is performed using TiCl₄, AlCl₃, Ar, N₂, and H₂ gases.

6. The method as defined by claim 5, wherein the ratio of H₂/N₂/Ar is between 20/5/50 sccm and 40/10/50 sccm.

7. A method as defined by claim 1, wherein the plasma chemical vapor deposition is performed using a radio frequency (RF) power between 40 W and 60 W at a temperature between 400°

C. and 500°

C. under a pressure between 1 Torr and 2 Torr.

8. A method as defined by claim 1, wherein “

x”

in Ti_(1-x)Al_xN has a value between 0.5 and less than 1.