Title :
A new cylindrical capacitor using hemispherical grained Si (HSG-Si) for 256Mb DRAMs
Author :
Watanabe, H. ; Tatsumi, T. ; Ohnishi, S. ; Hamada, T. ; Honma, I. ; Kikkawa, T.
Author_Institution :
Microelectron. Res. Labs., NEC Corp., Sagamihara, Japan
Abstract :
This HSG-Si cylindrical capacitor structure achieves a cell capacitance of 30 fF with 0.4 mu m-high storage electrode in a 0.72 mu m/sup 2/ cell area. A new selective etching technique using a low-pressure vapor hydrogen fluoride is developed to form the cylindrical capacitor electrode. The high selective etching (2000 times) of borophosphosilicate-glass to SiO/sub 2/ is realized. Disilane molecule irradiation in ultra-high vacuum chamber achieves the HSG-Si formation on the whole surface of phosphorous doped amorphous Si cylindrical electrode.<>
Keywords :
DRAM chips; capacitors; elemental semiconductors; etching; silicon; 256 Mbit; 30 fF; DRAMs; Si-SiO/sub 2/-BPSG; Si-SiO2-B2O3-P2O5-SiO2; cell capacitance; cylindrical capacitor; disilane molecule irradiation; hemispherical grained Si; low-pressure vapor hydrogen fluoride; seeding method; selective etching technique; ultra-high vacuum chamber; Capacitors; DRAM chips; Etching; Silicon;
Conference_Titel :
Electron Devices Meeting, 1992. IEDM '92. Technical Digest., International
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-0817-4
DOI :
10.1109/IEDM.1992.307355
