Low field electron mobility in 6H-SiC

Abstract

Experimental and theoretical studies of temperature and doping dependencies of electron mobility in 6H-SiC are reported. Low field electron mobility has been calculated by iterative technique and compared with experimental data. The following scattering mechanisms, i.e., impurity, polar optical phonon, acoustic phonon, and intervalley optical phonon are included in the calculation. Ionized and neutral impurity scattering have been treated beyond the Born approximation using a phase-shift analysis. We have found that neutral impurity scattering is very important in 6H-SiC due to large donor activation energy. Acceptor concentration is used as a parameter for fitting experimental data. Comparisons with published as well as our experimental data confirm the present calculation over a wide range of temperatures and electron concentrations.

Donor and acceptor concentration dependence of the electron Hall mobility and the Hall scattering factor in n-type 4H– and 6H–SiC

“…We have performed the theoretical calculation of the electron Hall mobility in nitrogen doped n-type 4Hand 6H-SiC as a function of temperature, net-doping concentration (͓N D ͔-͓N A ͔), and compensation ratio (͓N A ͔/͓N D ͔). [35][36][37] The electron Hall mobility has been calculated for two temperatures, Tϭ77 and 300 K, covering a wide range of the net-doping concentration ͓10 14 -10 18 (cm Ϫ3 )͔ and the compensation ratio ͑0-0.6͒. The contribution of various scattering mechanisms to the total electron Hall mobility has been found for both 4H-and for ͑a͒ 4H-SiC at Tϭ77 K, ͑b͒ 4H-SiC at Tϭ300 K, ͑c͒ 6H-SiC at T ϭ77 K, and ͑d͒ 6H-SiC at T ϭ300 K.…”

New materials for radiation hard semiconductor dectectors

“…High quality epitaxial n-type 6H-SiC shows electron Hall mobility values of ~200-300 cm 2 /Vs at room temperature, rising to 10 3 -10 4 cm 2 /Vs at 50K (Dhar et al 2000). In ptype SiC the hole mobility is typically around 50 cm 2 /Vs at room temperature.…”

Electrical Transport Properties of n-Type 4H and 6H Silicon Carbide

“…Several groups have calculated the Hall mobility between 50 K and 800 K and compared the computed values with experimental results [4,5]. Other authors have simultaneously described the carrier concentration [6,7,8] and determined the ionization energies.…”

“…For the purest samples, the acoustic phonon mode controls the temperature dependence of the mobility, and the acoustical deformation potential (C a ) is a basic parameter which must be accurately determined. The values of C a , determined by different authors for different doping level [4][5][6][8][9][10][11] are randomly distributed for 6H-SiC. For 4H-SiC they increase with the doping level.…”