Their mobility, also known as their ability to move through the crystal, will define the electrical performances of the device. Nevertheless, the most important parameter for all these devices is the mobility of the carrier flowing inside the channel.
Since, the field-effect transistor has taken several directions and is at the root of various devices such as the metal-oxide-semiconductor FET (MOSFET), dual gate MOSFET, junction FET, high electron mobility transistor, four-gate transistor and so on. The concept of employing an electric field to modulate the conductivity of a channel has been proposed first by Lilienfeld during the 1930s, long before its practical fabrication by Shockley et al. A methodology has been successfully implemented that led to the experimental verification of the universal behaviour of the mobility in an accumulation layer. Finally, the measurement of the mobility in an accumulation-mode MOSFETs is not straightforward since a bulk contribution, owing to the SOI layer, is adding to channel current. The study of the dependence of the scattering mechanism limiting the mobility in Si(110) n-MOSFETs showed that the Coulomb and surface roughness scattering mechanisms were responsible for the degradation of the mobility when compared to the one on Si(100) wafers. No relations were found for Si(100) wafers. The study of the relation between the mobility, channel direction and wafer orientation revealed that the channel direction had a significant impact on the mobility for transistors fabricated on Si(110) wafers, the highest electron and hole mobilites being obtained for a channel along the and directions, respectively. Authors then developed a more accurate mobility model able to simulate not only the drivability but also the transconductance for these same devices. They showed that the methods developed to extract the conduction parameters cannot be implemented for Si(110) p-MOSFETs. Authors investigate the carrier mobility in field-effect transistors mainly when fabricated on Si(110) wafers.
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