Carbon incorporation during growth of GaAs by TEGahyphen;AsH3base lowhyphen;pressure metalorganic chemical vapor deposition

摘要

Heavily carbonhyphen;doped GaAs (1times;1018sim;1times;1020cmminus;3) grown by lowhyphen;pressure metalorganic chemical vapor deposition using triethylgallium and arsine as sources and liquid carbonhyphen;tetrachloride (CCl4) as dopant has been investigated. The carrier concentration was verified at various growth temperatures, V/III ratios, and CCl4flow rates. Dopant concentration first increased from 550thinsp;deg;C and reached a maximum at 570thinsp;deg;C growth temperature (Tg) and then decreased monotonously. Carbon incorporation was strongly enhanced when the V/III ratio was less than 30 atTg=590thinsp;deg;C or less than 40 atTg=630thinsp;deg;C. Hole concentration increased and then decreased as CCl4flow rate increased. Growth rate of layers decreased as growth temperature and flow rate of CCl4increased. The doping efficiency of epitaxial layers grown on the (100) substrate was higher than that on the 2deg; off toward 110gsim; misoriented substrate. Carbonhyphen;doped GaAs films had higher Hall mobility than zinchyphen;doped GaAs films at high doping levels due to less selfhyphen;compensation. The highest dopant concentration in this system was 2.3times;1020cmminus;3atTg=580thinsp;deg;C and V/III=10.