SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE MANUFACTURING METHOD

• US 20100032837A1
• Filed: 10/11/2007
• Published: 02/11/2010
• Est. Priority Date: 10/12/2006
• Status: Active Grant

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Sameshima, Katsumi, Nakao, Yuichi, Kageyama, Satoshi, Nakagawa, Ryosuke, Yamaha, Takahisa
• Granted Patent: US 8,125,084 B2
• Time in Patent Office: Days
• US Class Current: 257/751
• CPC Class Codes: H01L 21/2855 by physical means, e.g. sputtering, evaporation H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/76808 involving intermediate temporary filling with material
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53295 Stacked insulating 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 semiconductor device according to the present invention includes: a semiconductor substrate; a first copper interconnection provided on the semiconductor substrate; an insulating layer provided over the first copper interconnection and having a hole extending therethrough to the first copper interconnection; a barrier layer composed of a tantalum-containing material and covering at least a sidewall of the hole and a part of the first copper interconnection exposed in the hole; and a second copper interconnection provided in intimate contact with the barrier layer and electrically connected to the first copper interconnection via the barrier layer; wherein the barrier layer has a nitrogen concentration profile such that the concentration of nitrogen contained in the material varies to be lower in a boundary portion of the barrier layer adjacent to the first copper interconnection and in a boundary portion of the barrier layer adjacent to the second copper interconnection and higher in an intermediate portion of the barrier layer defined between the boundary portions.

Claims

1. A semiconductor device comprising:

a semiconductor substrate;

a first copper interconnection provided on the semiconductor substrate;

an insulating layer provided over the first copper interconnection and having a hole extending therethrough to the first copper interconnection;

a barrier layer composed of a tantalum-containing material and covering at least a sidewall of the hole and a part of the first copper interconnection exposed in the hole; and

a second copper interconnection provided in intimate contact with the barrier layer and electrically connected to the first copper interconnection via the barrier layer;

wherein the barrier layer has a nitrogen concentration profile such that a concentration of nitrogen contained in the material varies to be lower in a boundary portion of the barrier layer adjacent to the first copper interconnection and in a boundary portion of the barrier layer adjacent to the second copper interconnection and higher in an intermediate portion of the barrier layer defined between the boundary portions.

2. A semiconductor device manufacturing method comprising:

a first copper interconnection forming step of forming a first copper interconnection on a semiconductor substrate;

an insulating layer forming step of forming an insulating layer over the first copper interconnection;

a hole forming step of forming a hole extending to the first copper interconnection in the insulating layer;

a barrier layer forming step of forming a barrier layer of a tantalum-containing material which covers at least a sidewall of the hole and a part of the first copper interconnection exposed in the hole by a sputtering method; and

a second copper interconnection forming step of forming a second copper interconnection in intimate contact with the barrier layer, the second copper interconnection being electrically connected to the first copper interconnection via the barrier layer;

wherein a nitrogen gas concentration in an ambient environment around the semiconductor substrate is controlled to be lower at an initial stage and a final stage of the barrier layer forming step, and is controlled to be higher at an intermediate stage of the barrier layer forming step.