The role of deep-level impurities in the drain characteristics of a short-channel metal-semiconductor field effect transistor has been investigated. The drain current of the device has been evaluated for different values of deep-level density and at different temperatures ranging from 300 to 400 K. The presence of deep levels gives rise to an excess drain current resulting from the electronic excitations from the defect levels. The increase in the temperature enhances the current due to increasing ionization of the defects. An analytical expression for the channel conductance is also derived and it is found to be a function of deep-level concentration besides other nonidealities such as interface states and interfacial oxide layer. The effect of gate length shortening also reveals significant changes in the current and conductance.

PROJNAN CHATTOPADHYAY

Electronic Science

L MAJUMDAR

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Effect of deep-level impurities on the drain characteristics of short-channel metal-semiconductor field effect transistors

Semiconductor Science and Technology

The dc characteristics of SOI MESFETs have been investigated considering the energy distribution of interface states, fixed charges in the insulating layer and the effect of back gate bias. It is shown that the depletion layer arising at the insulator-channel interface due to interface states and fixed charges, plays a vital role in fixing the device characteristics. In particular, the role of the above non-idealities on the drain current, pinch-off and threshold voltage of the device has been investigated. It has been found that, when a back gate bias is applied, the depletion layer width at the insulator-channel interface shrinks and the device regains its normal properties overcoming the effects caused by interface states and fixed charges.

The dc characteristics of a silicon-on-insulator metal-semiconductor field effect transistor

The short channel effect in a MESFET structure has been studied taking into consideration the effect of interface states and the presence of a residual oxide layer at the interface. The study reveals a considerable effect of interface states on the dc channel current and saturation transconductance of the device. The expression for saturation transconductance derived in this work shows explicit dependences on interfacial parameters unlike the conventional expression frequently used for simulation. It is shown that the characteristics are limited by pinning caused by the high density of interface states. © 1997 Elsevier Science B.V.

Applied Surface Science

Effect of interface states on the dc characteristics of short channel metal-semiconductor field effect transistor

The temperature dependence of threshold voltage of metal-semiconductor field effect transistors is studied considering a generalised interface state model and an uneven distribution of interface and bulk impurity states. The analysis predicts a sharp variation of threshold voltage with temperature which is in contrast to the conventionally known temperature dependence due to the band gap energy. The theoretical results are found in agreement with previous experimental findings.

Physica Status Solidi (A) Applied Research

Temperature dependence of threshold voltage of metal-semiconductor field effect transistors in the presence of an uneven distribution of interface and bulk states

The open-circuit voltage of an MIS solar cell is studied considering the presence of deep-level impurities. An expression for open-circuit voltage is proposed, which reduces to the well known expression for open-circuit voltage of an ideal metal-semiconductor solar cell under some limiting conditions. The analysis predicts an enhancement of open-circuit voltage for donor-like deep impurities. However, it is shown that due to recombination at the deep centres a loss in open-circuit voltage might occur. The conditions required to reduce the recombination loss are discussed.

Effect of deep-level impurities on the open-circuit voltage of an MIS solar cell

The barrier height of MIS tunnel diodes is studied considering the effect of deep impurities. It is shown that the barrier height of a given MIS-system can be controlled by changing the density and the activation energy of the defect level. The study leads to the conclusion that deep impurities of character opposite to shallow impurities enhance the barrier height. On the other hand, the barrier height is lowered when the type of the deep impurities is the same as that of shallow impurities. © 1991.

Journal	Data powered by TypesetSemiconductor Science and Technology
Publisher	Data powered by TypesetIOP PUBLISHING LTD
ISSN	0268-1242
Open Access	No