Title :
Interfacial-Layer-Driven Dielectric Degradation and Breakdown of HfSiON/SiON Gate Dielectric nMOSFETs
Author :
Do-Young Choi ; Kyong Taek Lee ; Chang-Ki Baek ; Chang Woo Sohn ; Hyun Chul Sagong ; Eui-Young Jung ; Jeong-Soo Lee ; Yoon-Ha Jeong
Author_Institution :
Dept. of Electr. Eng., Pohang Univ. of Sci. & Technol., Pohang, South Korea
Abstract :
This letter describes the dielectric degradation and breakdown characteristics of HfSiON/SiON gate dielectric nMOSFETs using the stress-induced leakage current (SILC) analysis. The nMOSFETs show progressive breakdown (PBD) under substrate injection stress, and its characteristic changes as the stress voltage increases, from slow PBD (s-PBD) only, then to a combination of s-PBD and fast PBD (f-PBD), and finally to f-PBD only. It is found that the SILC of nMOSFETs is caused by trap-assisted tunneling mainly through the preexisting deep traps of the high- k layer and the stress-induced traps of the interfacial layer (IL). The stress-induced defects under substrate injection stress are generated within the IL rather than the high- k layer, and the time-dependent dielectric breakdown of the nMOSFETs is driven by the degradation of the IL.
Keywords :
MOSFET; hafnium compounds; leakage currents; semiconductor device breakdown; silicon compounds; HfSiON-SiON; deep traps; gate dielectric nMOSFET; high-k layer; interfacial-layer-driven dielectric degradation; progressive breakdown; stress voltage; stress-induced defects; stress-induced leakage current analysis; stress-induced traps; substrate injection stress; time-dependent dielectric breakdown; trap-assisted tunneling; Degradation; Dielectrics; Electric breakdown; High K dielectric materials; Logic gates; MOSFETs; Stress; HfSiON; SiON; high-$k$ dielectric; interfacial layer (IL); positive bias temperature instability (BTI) (PBTI); reliability; stress-induced leakage current (SILC); time-dependent dielectric breakdown (TDDB);
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2011.2161861
