Title :
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
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;
Conference_Titel :
VLSI Technology, 1999. Digest of Technical Papers. 1999 Symposium on
Conference_Location :
Kyoto, Japan
Print_ISBN :
4-930813-93-X
DOI :
10.1109/VLSIT.1999.799327
