ABSTRACT
During the last decades, the field-effect transistor technology has changed at an amazing rate and improved its performance gradually. Mostly utilized transistor technology has been based on silicon transistors, but the technology is nearing its limits following scaling rules. Today, lots of efforts are made to expand metal oxide semiconductor field-effect transistors (MOSFETs) technology using III-V group semiconductor materials. These III-V semiconductor-based devices are likely to take the technology more due to enhanced material properties such as higher electron mobility. To attain high currents per unit area through the channel, high electron concentration in the channel as well as high drift velocity for electron is required. These high electron concentration and higher mobility help to achieve better transconductance and lower source and drain parasitic resistances. Therefore, integration of channel materials in CMOS technology having high mobility became a topic of intense research. Most III-V group materials of the periodic table (compound materials like InGaAs, InAs, GaAs, and InSb) can present enormously high electron mobility. InGaAs-based channel materials have an added advantage that allows tuning their bandgap by changing the mole fraction of the composition. When III-V group materials are appropriate for n-channel MOSFET operations, Ge, a group IV material and having relatively higher hole mobility, is ideal for p-channel MOSFET. However, mobility in these channel materials is inversely proportional to bandgap (EG). Achieving higher mobility lower EG is desirable but that in turn increases the OFF-state leakage current due to tunneling effect from drain to bulk or drain to source. Smaller EG also degrades scalability of the device and worsens SCEs. Therefore, proper study and careful analysis are very much important to integrate these high-mobility channel materials and improve performance for the emerging nanoscale devices.
