DocumentCode :
1407254
Title :
Band-to-band tunneling and thermal generation gate-induced drain leakage
Author :
Voldman, S.H. ; Fitzgerald, D.J.
Author_Institution :
IBM, Essex Junction, VT
Volume :
35
Issue :
12
fYear :
1988
fDate :
12/1/1988 12:00:00 AM
Firstpage :
2433
Abstract :
MOSFET oxide scaling for DRAM (dynamic random-access memory) applications can be limited by gate-induced diode leakage, which has been shown previously by experiments at cryogenic temperatures to consist of a thermal volume generation and a band-to-band tunneling mechanism. Tunneling is the dominant mechanism at relatively higher voltages and cryogenic temperatures. The authors have studied the leakage as a function of low applied bias and made low-temperature measurements (25 K to 400 K) of this mechanism, using a submicrometer N + polysilicon gate CMOS process. They have also studied the tunnel current dependence on gate-to-drain bias, dielectric thickness, gate-to-drain overlap, flatband voltage and bandgap narrowing for n- and p-channel devices. Experimentally the leakage current characteristic satisfies an exp(-B/Es) relationship, where Es is the electric field at the silicon dioxide-silicon interface. The coefficient B contains the tunneling temperature dependence. The leakage current has strong oxide-thickness, flatband, and voltage dependencies. By withdrawing the diffusion edge, thereby reducing the overlap area, the tunnel current decreases and has a gate voltage dependency. The gated-diode leakage impact on MOSFET dielectric scaling can be reduced by scaling gate-to-diffusion overlap
Keywords :
insulated gate field effect transistors; leakage currents; semiconductor device testing; tunnelling; 25 to 400 K; DRAM; MOSFET oxide scaling; SiO2-Si interface; band-to-band tunneling; bandgap narrowing; cryogenic temperatures; dielectric thickness; flatband voltage; gate-to-drain bias; gate-to-drain overlap; leakage current characteristic; submicrometer N+ polysilicon gate CMOS process; thermal generation gate-induced drain leakage; thermal volume generation; CMOS process; Cryogenics; Dielectric measurements; Diodes; Dynamic voltage scaling; Leakage current; MOSFET circuits; Random access memory; Temperature; Tunneling;
fLanguage :
English
Journal_Title :
Electron Devices, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9383
Type :
jour
DOI :
10.1109/16.8842
Filename :
8842
Link To Document :
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