Title :
The effects of biaxially-tensile strain to properties of Si/SiO2 interface states generated by electrical stress
Author :
Cai, W.-L. ; Takenaka, Mitsuru ; Takagi, Shinichi
Author_Institution :
Sch. of Eng., Univ. of Tokyo, Tokyo, Japan
Abstract :
In this paper, the effects of biaxially-tensile strain on the properties of Si/SiO2 interface states generated by FN stress have been systematically investigated. In order to accurately evaluate interface state density (Dit) in MOS capacitors and FETs including strained-Si (sSi)/SiGe hetero-interfaces, the conductance method and the S-factor method have been properly modified. It is found that strain does not strongly change the properties of SiO2/Si interface states. On the other hand, almost similar ΔDit and smaller ΔVth is observed in sSi n-MOSFETs after FN stress. These inconsistent behaviors between ΔDit and ΔVth can be explained by the relative shift of the charge neutrality level inside the band gap of strained Si.
Keywords :
Ge-Si alloys; MOS capacitors; MOSFET; elemental semiconductors; energy gap; interface states; silicon; silicon compounds; tensile strength; FN stress; MOS capacitors; S-factor method; Si-SiGe; Si-SiO2; band gap; biaxially-tensile strain; charge neutrality level; conductance method; electrical stress; interface state density; n-MOSFET; strained-Si-SiGe hetero-interfaces; Capacitance; Interface states; Silicon; Silicon germanium; Strain; Stress; charge neutrality level; hetero-interface; interface state; strained Silicon;
Conference_Titel :
Reliability Physics Symposium, 2014 IEEE International
Conference_Location :
Waikoloa, HI
DOI :
10.1109/IRPS.2014.6861183
