Title :
Low contact resistance metallization for gigabit scale DRAMs using fully-dry cleaning by Ar/H2 ECR plasma
Author :
Taguwa, T. ; Urabe, K. ; Sekine, M. ; Yamada, Y. ; Kikkawa, T.
Author_Institution :
ULSI Device Dev. Lab., NEC Corp., Sagamihara, Japan
Abstract :
This paper describes a fully-dry cleaning technique with Ar/H2 Electron Cyclotron Resonance (ECR) plasma as a low contact resistance metallization technology for gigabit scale DRAM contacts. Extremely low contact resistances of 296 Ω and 350 Ω for 0.3 μm contact diameter with aspect ratio of 7 were realized on n+ and p+ diffusion layers, respectively. No leakage current was observed. By using this technology, a DRAM ULSI, which was planarized by Chemical Mechanical Polishing (CMP) and had deep contact holes with aspect ratio of 6, was successfully fabricated
Keywords :
DRAM chips; ULSI; contact resistance; integrated circuit metallisation; plasma applications; polishing; surface cleaning; 296 ohm; 350 ohm; Ar; Ar-H2; Ar/H2 ECR plasma; CMP; DRAM ULSI; DRAM contacts; H2; chemical mechanical polishing; electron cyclotron resonance plasma; fully-dry cleaning; gigabit scale DRAMs; low contact resistance metallization; planarization; Argon; Chemical technology; Cleaning; Contact resistance; Cyclotrons; Electrons; Metallization; Plasmas; Random access memory; Resonance;
Conference_Titel :
Electron Devices Meeting, 1995. IEDM '95., International
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-2700-4
DOI :
10.1109/IEDM.1995.499314
