Title :
A physical model for hole direct tunneling current in p+ poly-gate pMOSFETs with ultrathin gate oxides
Author :
Yang, Kuo-Nan ; Huang, Huan-Tsung ; Chang, Ming-Chin ; Chu, Che-Min ; Chen, Yuh-Shu ; Chen, Ming-Jer ; Lin, Yeou-Ming ; Mo-Chiun Yu ; Jang, Simon M. ; Yu, Mo-Chiun ; Liang, M.S.
Author_Institution :
Inst. of Electron., Nat. Chiao Tung Univ., Hsinchu, Taiwan
fDate :
11/1/2000 12:00:00 AM
Abstract :
A model of the hole direct tunneling gate current accounting for heavy and light hole´s subbands in the quantized inversion layer is built explicitly. This model comprises four key physical parameters: inversion layer charge density, hole impact frequency on SiO2-Si interface, WKB transmission probability, and reflection correction factor. With the effective hole mass moxh =0.51 Mo for the parabolic dispersion relationship in the oxide, experimental reproduction without any parameter adjustment is consistently achieved in p+ poly-gate pMOSFETs with 1.23, 1.85, and 2.16 nm gate oxide thicknesses. The proposed model can thereby serve as a promising characterization means of direct tunnel oxides. In particular, it is calculated that the secondary subbands and beyond, although occupying few holes, indeed contribute substantially to the direct tunneling conduction due to effective lower barrier heights, and are prevailing over the first subbands for reducing the oxide field down below 1 MV/cm
Keywords :
MOSFET; dielectric thin films; probability; semiconductor device models; semiconductor-insulator boundaries; tunnelling; 1.23 to 2.16 nm; SiO2-Si; SiO2-Si interface; WKB transmission probability; direct tunnel oxides; direct tunneling conduction; effective hole mass; effective lower barrier heights; hole direct tunneling current; hole impact frequency; inversion layer charge density; p+ poly-gate pMOSFETs; parabolic dispersion relationship; parameter extraction; physical model; quantized inversion layer; reflection correction factor; secondary subbands; tunneling gate current; ultrathin gate oxides; Dispersion; Electrons; Frequency; Helium; Lead compounds; MOSFET circuits; Optical reflection; Power MOSFET; Surface fitting; Tunneling;
Journal_Title :
Electron Devices, IEEE Transactions on