Abstract:
Silicon-on-insulator (SOl) MOSFET is one of the modem state of the art transistor in
Qruch a semiconductor layer like silicon is formed above an insulator layer on a semiconductor
substrate. In SOl MOSFET, there is much more advantages over bulk silicon MOSFET such as
high speed operation, low power consumption, small short channel effects. Over the past several
years, the inherent scaling limitations of silicon (Si) electron devices have fuelled the exploration
of alternative semiconductors, with high carrier mobility, to further enhance device performance.
In particular, compound semiconductors heterogeneously integrated on Si substrates have been
actively studied: such devices combine the high mobility of lII-V semiconductors and the well
established, low-cost processing of Si technology. This integration, however, presents significant challenges. Conventionally, heteroepitaxial growth of complex multilayers on Si has been
explored but besides complexity, high defect densities and junction leakage currents present
limitations in this approach. Motivated by this challenge, we use a three surface potentials (gate
oxide-silicon film interface, silicon-film-buried oxide interface and buried oxide-substrate
interface) based compact model to study a fully depleted SOl and XOI MOSFETs. We have
simulated the surface potentials, surface charge density, gate capacitance, drain current,
transconductance and unity gain frequency of SOl and XOI MOSFETs. The different output
characteristics show a better performance for InAs. We have got high drain current transconductance and unity gain frequency of XOI MOSFET. On the other hand, we got very
low (negative) threshold voltage for XOI MOSFET. So, by using XOI MOSFET, we can get
high speed operation and amplification, low power consumption than SOl MOSFET as well as
bulk silicon MOSFET.
Description:
This thesis submitted in partial fulfillment of the requirements for the degree of B.Sc in Electrical and Electronic Engineering of East West University, Dhaka, Bangladesh.