Title:
On the enhancement of the drain current in Indium rich InGaAs surface channel MOSFETs
Authors:
A. T. M. Golam Sarwar, M. R. Siddiqui, Md. M. Satter, and Anisul Haque
Publication Area:
Nanoelectronic transistors
Abstract:
Effects of interface trap states ($D_{it}$) and the shift of the charge neutrality level (CNL) on the enhancement of the drain current in In rich surface channel, enhancement-mode, n-type
InGaAs MOSFETs are investigated. In addition to the increase in
the bulk mobility, the shift of CNL towards the conduction band
together with high densities of $D_{it}$ are responsible for the
experimentally observed remarkable enhancement of the on-state
drain current with increasing In content in the channel. However,
when $D_{it}$ density is low, current enhancement is weak and the location of CNL has little effect on the current enhancement.
Acceptor-type interface trap states above the conduction band
minima (CBM) play an important role in determining the inversion
layer electron mobility. Representing $D_{it}$ distribution above
the CBM by a constant equal to the $D_{it}$ value at CNL causes
an over-estimation of the drain current at higher gate voltages.
It is also observed that the extraction of $D_{it}$ from the
low-frequency gate C-V data is independent of the location of
CNL. We further show that the subthreshold slope (SS) is doubled
due to $D_{it}$. However, the location of CNL or the density of
$D_{it}$ above CBM has little effect on SS.
Source: IEEE Transactions on Electron Devices , vol. 59, no. 6, pp.1653-1660
Year: 2012
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