Browsing by Author "Fu, KY"

Now showing 1 - 3 of 3

Forward gated-diode measurement of filled traps in high-field stressed thin oxides
(2000-08-01)
Chen, MJ
;
Kang, TK
;
Huang, HT
;
Liu, CH
;
Chang, YJ
The forward gated-diode monitoring technique can find its potential applications in assessing the filled traps in MOSFET thin oxides, which are subjected to high-field stressing and then followed by hot-electrons filling scheme. Our measurement of the gate voltage shift associated with the forward current peak produces a power lan relation between the filled trap density and the electron stress fluence, indeed in close agreement with that obtained by MOSFET threshold voltage shift.
Low-frequency noise in n-channel metal-oxide-semiconductor field-effect transistors undergoing soft breakdown
(2001-01-01)
Chen, MJ
;
Kang, TK
;
Lee, YH
;
Liu, CH
;
Chang, YJ
For 3.3-nm thick gate oxide n-channel metal-oxide-semiconductor field-effect transistors subject to a stress gate voltage of 5.5 V, three distinct events are encountered in the time evolution of the gate current: stress-induced leakage current (SILC), soft breakdown (SBD), and hard breakdown (HBD). The localization of SBD and HBD paths, as well as their developments with the time, is determined electrically, showing random distribution in nature. At several stress times, we interrupt the stressing to measure the drain current low-frequency noise power S-id. As expected, S-id follows up the spontaneous changes at the onset of SBD and HBD. The S-id spectra measured in fresh and SILC mode are reproduced by a literature model accounting for the carrier number and surface mobility fluctuations in the channel, and, as a result, both preexisting and newly generated trap densities are assessed. The post-SBD S-id does originate from current fluctuations in the SBD percolation paths, which can couple indirectly to drain via underlying channel in series, or directly to drain if the SBD path is formed close to drain extension. In particular, a fluctuation in S-id itself in the whole SBD duration is observed. This phenomenon is very striking since it indeed evidences the dynamic percolation origin concerning the trapping-detrapping processes in and around the SBD paths. The subsequent HBD duration remarkably features a flat S-id, indicating the set-up of a complete conductive path prevailing over the trapping-detrapping processes. (C) 2001 American Institute of Physics.
Oxide thinning percolation statistical model for soft breakdown in ultrathin gate oxides
(2000-07-24)
Chen, MJ
;
Kang, TK
;
Liu, CH
;
Chang, YJ
;
Fu, KY
An existing cell-based percolation model with parameter correlation can find its potential applications in assessing soft-breakdown (BD) statistics as long as the oxide thinning due to the localized physical damage near the SiO2/Si interface is accounted for. The resulting model is expressed explicitly with the critical trap number per cell n(BD) and the remaining oxide thickness t(ox)(') both as parameters. Reproduction of time-to-bimodal (soft- and hard-) breakdown statistical data from 3.3-nm-thick gate-oxide samples yields n(BD) of 3 and 4 for soft and hard breakdown, respectively. The extracted t(ox)(') of 1.0 nm for soft breakdown, plus the transition layer thickness of 0.5 nm in the model, is fairly comparable with literature values from current-voltage fitting. The dimension and area of the localized physically damaged region or percolation path (cell) are quantified as well. Based on the work, the origins of soft and hard breakdown are clarified in the following: (i) soft breakdown behaves intrinsically as hard breakdown, that is, they share the same defect (neutral trap) generation process and follow Poisson random statistics; (ii) both are independent events corresponding to different t(ox)(') requirements; and (iii) hard breakdown takes place in a certain path located differently from that for the first soft breakdown. (C) 2000 American Institute of Physics. [S0003-6951(00)02130-6].