Title :
A study of stress-induced p+/n salicided junction leakage failure and optimized process conditions for sub-0.15-μm CMOS technology
Author :
Lee, Joo-Hyoung ; Park, Sung-Hyung ; Lee, Key-Min ; Youn, Ki-Seok ; Park, Young-Jin ; Choi, Chel-Jong ; Seong, Tae-Yeon ; Lee, Hi-Deok
Author_Institution :
Logic Device Dev. Team, Hynix Semicond. Inc., Cheongju, South Korea
fDate :
11/1/2002 12:00:00 AM
Abstract :
We have clarified that mechanical stress combined with a shallower junction at the active edge is the main cause of junction leakage current failure of shallow p+/n salicided junctions for sub-0.15-μm CMOS technology, especially those with narrow active width. Mechanical stress results in the penetration of a Self-Aligned siLICIDE (SALICIDE) layer at the corner region of the narrow active line. Moreover, a novel electrochemical etching with TEM shows shallower junctions at the active edge due to the bending up of the junction profile. We found that the application of a shallow trench isolation (STI), top corner rounding (TCR) process suppresses the mechanical stress of STI´s top corner and thus eliminates the stress-induced p+/n salicided junction leakage failure. Furthermore, we optimized the Co SALICIDE process using a Ge+ pre-amorphization in a narrow p+/n salicided junction.
Keywords :
CMOS integrated circuits; etching; failure analysis; integrated circuit reliability; internal stresses; isolation technology; leakage currents; p-n junctions; stress effects; transmission electron microscopy; 0.15 micron; CMOS technology; Co salicide process; CoSi2; Ge; Ge+ pre-amorphization; STI; TEM; electrochemical etching; failure model; mechanical stress; optimized process conditions; self-aligned silicide layer; shallow p+/n salicided junction; shallow trench isolation; stress-induced junction leakage failure; top corner rounding process; Atomic force microscopy; CMOS process; CMOS technology; Etching; Leakage current; Logic devices; Materials science and technology; Research and development; Silicides; Stress;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2002.804704