Title:
SELECTIVE ETCHANT AND METHOD OF Ti-W
Document Type and Number:
Japanese Patent JP3184180
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To realize an etching liquid and a method, by which a Ti-W(titanium- tungsten) alloy thin film is removed in a process where a solder bump electrode is formed on a semiconductor device.
SOLUTION: An alloy layer which is to be removed is preferably composed of 10% Ti and 90% W and formed on a substrate 11 under a copper conductive metal layer used for plating a solder bump electrode 15. A Ti-W layer 12 is etched using, the solder bump electrode 15 as a mask. A Ti-W etching liquid must dissolve the Ti-W layer 12 quickly, without etching aluminum, copper, and lead-tin solder. In this case, 30 wt.% hydrogen peroxide solution in which disodium hydrogen phosphate is added is used, and furthermore potassium dihydrogen phosphate is added, if necessary.
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Inventors:
Masaaki Kadoi
Sadao Kojima
Sadao Kojima
Application Number:
JP12112299A
Publication Date:
July 09, 2001
Filing Date:
April 28, 1999
Export Citation:
Assignee:
Seiko Instruments Inc.
International Classes:
H01L21/308; C23F1/26; H01L21/60; (IPC1-7): H01L21/308; C23F1/26
Domestic Patent References:
| JP63305518A | ||||
| JP853781A | ||||
| JP11219946A |
Attorney, Agent or Firm:
Keinosuke Hayashi