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US005385867A
United States Patent [193 [ii] Patent Number: 5,385,867
Ueda et al. [45] Date of Patent: Jan. 31,1995
[54] METHOD FOR FORMING A MULTI-LAYER METALLIC WIRING STRUCTURE
[75] Inventors: Tetsuya Ueda; Kousaku Yano;
Tomoyasu Murakami; Michinari
Yamanaka; Shuji Hirao, all of Osaka;
Noboru Nomura, Kyoto, all of Japan
[73] Assignee: Matsushita Electric Industrial Co., Ltd., Kadoma, Japan
[21] Appl. No.: 216,968
[22] Filed: Mar. 24,1994
[30] Foreign Application Priority Data
Mar. 26, 1993 [JP] Japan 5-068541
[51] Int. CI.« H01L 21/283; H01L 21/31
[52] U.S. CI 437/195; 437/189;
437/192; 437/194; 437/228; 437/229
[58] Field of Search 437/189, 192, 194, 195,
437/228, 229; 156/659.1, 660
[56] References Cited
U.S. PATENT DOCUMENTS
4,536,951 8/1985 Rhodes et al 437/190
4,614,021 9/1986 Hulseweh 437/189
4,842,991 6/1989 Brighton 437/229
4,892,845 1/1990 Bridges 437/195
4,914,056 4/1990 Okumura 437/192
4,952,528 8/1990 Abe et al 437/194
4,957,881 9/1990 Crotti 437/195
4,987,099 1/1991 Flanner 437/192
4,996,167 2/1991 Chen 437/40
5,006,484 4/1991 Harada 437/192
5,204,286 4/1993 Doan 437/195
FOREIGN PATENT DOCUMENTS 61-208851 9/1986 Japan .
After accumulating a BPSG film layer on a silicon substrate, a first Al—Si—Cu film layer, a W film layer and a second Al—Si—Cu film layer are successively accumulated on this BPSG film layer. A resist pattern with wide-width and narrow-width pattern portions is formed on the second Al—Si—Cu film layer. The widewidth pattern portion is provided at a position corresponding to a contact for connecting a first-layer metallic wiring and a second-layer metallic wiring, while the narrow-width pattern portion is provided at a position corresponding to a wiring portion for the first-layer metallic wiring. After applying first etching on the second Al—Si—Cu film layer with a mask of the resist patter, second etching is applied on the W film layer. Thereafter, by applying third etching, the resist pattern remaining on the first-layer metallic wiring is removed and the first Al—Si—Cu film layer is transfigured into a tall metallic film portion and a short metallic film portion. After accumulating an inter-layer insulating film layer on the first Al—Si—Cu film layer, etchback is applied on this inter-layer insulating film layer until the top of the tall metallic film portion is bared. Then, the second-layer metallic wiring is formed on the interlayer insulating film layer so that the second-layer metallic wiring is connected with the tall metallic film portion.
7 Claims, 20 Drawing Sheets
