Aluminum word line and bit line fabrication technology for COB DRAM using a polysilicon-aluminum substitute

Author

Nakamura, S. ; Suzuki, R. ; Fukuda, M. ; Kobayashi, M. ; Hatada, A.

Author_Institution

Fujitsu Labs. Ltd., Atsugi, Japan

fYear

1999

fDate

14-16 June 1999

Firstpage

35

Lastpage

36

Abstract

It is possible to employ the low resistance (but low melting point) material aluminum in word lines and bit lines for COB (capacitor-over-bit line) type DRAM or DRAM/logic, even though high temperature processes are adapted after word line and bit line fabrications. Aluminum successfully diffuses into 0.1-0.5 /spl mu/m width primary polysilicon lines through polysilicon vertical plugs using the polysilicon-aluminum substitute (PAS) technique (Horie et al, IEDM Tech. Dig., p. 946, 1996) after completion of all high temperature processes. This aluminum line provides enough length to create even 512 bit/line, with high purity (99% Al), large grains and low resistance.

Keywords

DRAM chips; aluminium; chemical interdiffusion; electric resistance; elemental semiconductors; grain size; integrated circuit interconnections; integrated circuit metallisation; melting point; silicon; 0.1 to 0.5 micron; Al; Al bit line fabrication technology; Al purity; Al word line fabrication technology; Al-Si; COB type DRAM; COB type DRAM/logic; Si:Al; aluminum; aluminum diffusion; aluminum line; bit line fabrication; bit lines; capacitor-over-bit line type DRAM; capacitor-over-bit line type DRAM/logic; grain size; high temperature processes; melting point; polysilicon vertical plugs; polysilicon-aluminum substitute; polysilicon-aluminum substitute technique; primary polysilicon lines; resistance; word line fabrication; word lines; Aluminum; Artificial intelligence; Etching; Fabrication; Plugs; Random access memory; Resists; Temperature; Tin; Wiring;

fLanguage

English

Publisher

ieee

Conference_Titel

VLSI Technology, 1999. Digest of Technical Papers. 1999 Symposium on

Conference_Location

Kyoto, Japan

Print_ISBN

4-930813-93-X

Type

conf

DOI

10.1109/VLSIT.1999.799327

Filename

799327