Method of improving the texture of aluminum metallization for tungsten etch back processing

• US 6,329,282 B1
• Filed: 07/08/1999
• Issued: 12/11/2001
• Est. Priority Date: 09/11/1998
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Hsu, Wei-Yung, Hong, Qi-Zhong
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): GURLEY, LYNNE ANN
• Application Number:
  US09/349,624
• Time in Patent Office: 887 Days
• Field of Search: 438/625, 438/627, 438/629, 438/635, 438/643, 438/648, 438/653, 438/656, 438/658, 438/672, 438/685, 438/688
• US Class Current: 438/625
• CPC Class Codes: H01L 21/32115 Planarisation
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76867 characterized by methods of formation other than PVD, CVD or deposition from a liquids PVD H01L21/2855; CVD H01L21/28556; deposition from liquids H01L21/288
• 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

Abstract

A method of making connection between an aluminum or aluminum based material and tungsten. The method includes providing an underlying region containing a layer of tungsten thereover. The underlying region is preferably a layer of titanium over which is a layer of titanium nitride. The layer of tungsten is etched back to the underlying region while exposed tungsten is retained over a portion of the underlying region. The underlying region also may contain a via therein which contains the exposed tungsten. An nitrogen-containing plasma, preferably elemental nitrogen, is then applied to the exposed tungsten and exposed underlying region and a layer of a barrier material is formed by reaction of the nitrogen in the plasma and the tungsten over the exposed tungsten. A further barrier layer, preferably titanium nitride, is optionally then applied followed by a layer of aluminum over the exposed surface, the barrier layer isolating the layer of aluminum from the tungsten. Plasma is preferably an argon/nitrogen plasma.

Claims

1. A method of aluminum crystal orientation control, comprising:

(a) providing a surface including a first portion consisting essentially of tungsten and a second portion consisting essentially of titanium nitride;

(b) exposing said surface to a nitrogen-containing plasma;

(c) forming an aluminum layer over the surface;

(d) whereby the exposing of step (b) removes contaminants and thereby controls the crystal orientation of the aluminum over both the tungsten and the titanium nitride.

2. The method of claim 1, further comprising:

(a) forming a barrier layer on the surface after the exposing of step (b) of claim 1; and

(b) the forming an aluminum layer of step (c) of claim 1 is depositing aluminum on the barrier layer.

3. The method of claim 2, wherein:

(a) the barrier layer is titanium nitride.