Title :
High-field breakdown in thin oxides grown in N2O ambient
Author :
Joshi, Aniruddha B. ; Yoon, Giwan ; Kim, Jonghan ; Lo, G.Q. ; Kwong, Dim-Lee
Author_Institution :
Dept. of Electr. & Comput. Eng., Texas Univ., Austin, TX, USA
fDate :
8/1/1993 12:00:00 AM
Abstract :
A detailed study of time-dependent dielectric breakdown (TDDB) in N2O-grown thin (47-120 Å) silicon oxides is reported. A significant degradation in breakdown properties was observed with increasing oxide growth temperatures. A physical model based on undulations at the Si/SiO2 interface is proposed to account for the degradation. Accelerated breakdown for higher operating temperatures and higher oxide fields as well as thickness dependence of TDDB are studied under both polarities of injection. Breakdown under unipolar and bipolar stress in N2O oxides is compared with DC breakdown. An asymmetric improvement in time-to-breakdown under positive versus negative gate unipolar stress is observed and attributed to charge detrapping behavior in N2O oxides. A large reduction in time-to-breakdown is observed under bipolar stress when the thickness is scaled below 60 Å. A physical model is suggested to explain this behavior. Overall, N2O oxides show improved breakdown properties compared with pure SiO2
Keywords :
electric breakdown of solids; electron traps; insulating thin films; silicon compounds; DC breakdown; N2O; Si-SiO2; bipolar stress; breakdown properties; charge detrapping behavior; operating temperatures; oxide fields; oxide growth temperatures; physical model; time-dependent dielectric breakdown; undulations; unipolar stress; Acceleration; Charge carrier processes; Degradation; Dielectric devices; Electric breakdown; Electric fields; Electron traps; Oxidation; Stress; Temperature dependence;
Journal_Title :
Electron Devices, IEEE Transactions on
