Browsing by Author "CHAO, KC"

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FOWLER-NORDHEIM LIMITED BAND-TO-BAND TUNNELING (FNBB) FOR P-MOSFET GATE CURRENT IN A FLOATING BULK CONDITION
(1995-01-01)
CHAO, KC
;
CHEN, MJ
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new mechanism of Fowler-Nordheim tunneling limited band-to-band tunneling (FNBB) has been identified to be responsible for the gate current measured from p-MOSFETs with the bulk (n-well) floated. This mechanism has been found to occur in the gate-to-drain overlap region. Two-dimensional device simulations have successfully reproduced this gate current and thus the physical parameter values of the band-to-band tunneling model have been obtained.
GATE AND DRAIN CURRENTS IN OFF-STATE BURIED-TYPE P-CHANNEL LDD MOSFETS
(1992-12-01)
CHEN, MJ
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CHAO, KC
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HUANG, TH
;
TSAUR, JM
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電控工程研究所
The buried-type p-channel LDD MOSFET's biased at high positive gate voltage exhibit new characteristics: 1) the ratio of the drain to gate currents is about 1 X 10(-3) to 5 X 10(-3); and 2) the gate and drain currents both are functions of only the gate voltage minus the n-well bias. Such characteristics are addressed based on the formation of the surface n+ inversion layer due to the punchthrough of the buried channel to the underlying shallow p-n junction. The measured gate current is due to the Fowler-Nordheim tunneling of electrons from this inversion layer surface and the holes generated within the high-field oxide constitute the drain current. The n+ inversion layer surface potential is found to be equal to the n-well bias plus 0.55 V. As a result, not only the oxide field but also the gate and drain currents are independent of drain voltage.
NEW OBSERVATION AND THE MODELING OF GATE AND DRAIN CURRENTS IN OFF-STATE P-MOSFETS
(1994-05-01)
CHEN, MJ
;
CHAO, KC
;
CHEN, CH
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The work reports new observations concerning the gate and drain currents measured at off-state conditions in buried-type p-channel LDD MOSFET devices. Detailed investigation of the observed phenomena reveals that 1) the drain current can be separated into two distinct components: band-to-band tunneling in the gate-to-drain overlap region and collection of holes generated via impact ionization by electrons inside the oxide; and 2) the gate current can be separated into two distinct components: the hot electron injection into the oxide and the Fowler-Nordheim electron tunneling through the oxide. At low negative drain voltage, the dominant component of the drain current is the hole generation inside the oxide. At high negative drain voltage, the drain current is essentially due to band-to-band tunneling, and it is correlated with the hot-electron injection-induced gate current.