ANALYSIS AND MODELING OF TEMPERATURE, PRESSURE AND COMPENSATION RATIO DEPENDENCE OF MOBILITY OF CHARGE CARRIERS IN THE THREE CONDUCTION BANDS OF GaAs

Abstract

In recent years, considerable interest has developed toward the study and use of compound semiconductors. The material about which the most detailed information is available possess direct energy gap and are derived from elements in columns III and V of the periodic table. Compound semiconductors are peculiarly useful because electron transport at high electric field is dominated by the complex conduction-band structure well above the lowest band edge. Devices relying on the influence of the energy areas of the conduction band represent a new class of applications. GaAs is one of the most important compound semiconductor. It is widely used because of its high mobility feature. Electron mobility is a popular parameter used to characterize the microscopic quality of crystal. The electron drift mobility of GaAs for F valley is presented as a function of temperature. Ionized impurity, polar mode, deformation potential and piezoelectric scatterings are included in mobility calculations. Accurate comparison between experimental and theory are important for determining a variety of fundamental material constants and electron scattering mechanisms. Room temperature mobility for r valley is found nearly 9094 cmz/V-Sec. A good agreement between theory and experimental data is found over the temperature region from liquid nitrogen to room temperature for L and X valleys of GaAs. Theoretical mobility calculations have been carried out for electrons in the L valleys of GaAs with the aid of Ge & GaAs data. Room temperature mobility for L valleys is found nearly 945 cm2/V-Sec. Similarly, X valleys mobilities are calculated with the aid of Si & GaP data with temperature variation for carrier concentrations in the range 1014 /cm3 to 1018 /cm3. Room temperature mobility for X valleys is found nearly 247 cm2fV-Sec Experimental data from Hall measurement for above mentioned carrier concentration range provide essential confirmation of the present results.