Title :
A Gbit-scale DRAM stacked capacitor technology with ECR MOCVD SrTiO/sub 3/ and RIE patterned RuO/sub 2/TiN storage nodes
Author :
Lesaicherre, P.-Y. ; Yamamichi, S. ; Yamaguchi, H. ; Takemura, K. ; Watanabe, H. ; Tokashiki, K. ; Satoh, K. ; Sakuma, T. ; Yoshida, M. ; Ohnishi, S. ; Nakajima, K. ; Shibahara, K. ; Miyasaka, Y. ; Ono, H.
Author_Institution :
ULSI Device Dev. Lab., NEC Corp., Sagamihara, Japan
Abstract :
A new stacked capacitor technology with high permittivity ECR MOCVD SrTiO/sub 3/ films on 1 Gbit compatible RuO/sub 2/TiN storage nodes was developed for Gigabit-scale DRAMs. A cell capacitance of 25 fF and leakage current density of 8/spl times/10/sup -7/ A/cm/sup 2/ can be achieved with this capacitor technology, using 0.5 /spl mu/m high stacked storage electrodes in a 0.125 /spl mu/m/sup 2/ capacitor area. Fine storage RuO/sub 2/TiN electrodes were patterned down to 0.2 /spl mu/m by electron beam lithography and RIE using an O/sub 2/-based etching mixture. A new low temperature ECR MOCVD technique was also developed to prepare highly reliable SrTiO/sub 3/ films to be used on the storage electrode sidewalls.<>
Keywords :
DRAM chips; capacitor storage; chemical vapour deposition; electrodes; electron beam lithography; leakage currents; semiconductor technology; sputter etching; strontium compounds; thin film capacitors; 0.2 mum; 0.5 mum; 1 Gbit/s; 25 fF; ECR MOCVD; Gbit-scale DRAM stacked capacitor technology; O/sub 2/-based etching mixture; RIE patterned; RuO/sub 2/; RuO/sub 2/TiN storage nodes; SrTiO/sub 3/; TiN; cell capacitance; electron beam lithography; high permittivity; high stacked storage electrodes; highly reliable SrTiO/sub 3/ films; leakage current density; low temperature ECR MOCVD technique; stacked capacitor technology; storage electrode sidewalls; thin film capacitors; Capacitance; Capacitors; Electrodes; Electron beams; Leakage current; Lithography; MOCVD; Permittivity; Random access memory; Tin;
Conference_Titel :
Electron Devices Meeting, 1994. IEDM '94. Technical Digest., International
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-2111-1
DOI :
10.1109/IEDM.1994.383296
