Title :
Differential capacitance measurements of relaxation-induced defects in InGaAs/GaAs Schottky diodes
Author :
Jenn-Fang Chen ; Nie-Chuan Chen ; Wang, Jiin-Shung ; Chen, Nie-Chuan
Author_Institution :
Dept. of Electrophys., Nat. Chiao Tung Univ., Hsinchu, Taiwan
fDate :
2/1/2001 12:00:00 AM
Abstract :
The use of a differential capacitance technique for characterizing the relaxation-induced defect states in Schottky diodes has been studied. Based on a proposed equivalent circuit including the effect of potential drop across the carrier-depletion layer, a simple equation of capacitance at different voltages and frequencies is derived and compared with experimental data obtained from relaxed In0.2Ga 0.8As/GaAs samples. It is shown that the carrier-depletion layer will introduce capacitance dispersion over frequency like traps; from it the device´s geometric parameters, the resistance of the carrier-depletion layer and the ionization energy of the deep level that gives rise to this resistance can be obtained. The relation between the low-frequency capacitance and reverse voltage can be explained well by the depletion of the free carriers between the Schottky depletion and the carrier-depletion layer. The relaxation-induced traps are believed to be at 0.535 and 0.36 eV, respectively, in the GaAs and In0.2 Ga0.8As regions
Keywords :
III-V semiconductors; Schottky diodes; capacitance; deep levels; defect states; equivalent circuits; gallium arsenide; indium compounds; semiconductor device measurement; semiconductor device models; In0.2Ga0.8As-GaAs; InGaAs/GaAs Schottky diodes; Schottky depletion; capacitance dispersion; carrier-depletion layer; deep level; differential capacitance measurements; equivalent circuit; free carriers depletion; geometric parameters; ionization energy; layer resistance; low-frequency capacitance; potential drop; relaxation-induced defects; relaxation-induced traps; reverse voltage; Capacitance measurement; Differential equations; Equivalent circuits; Frequency; Gallium arsenide; Indium gallium arsenide; Ionization; Schottky diodes; Spectroscopy; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on
