Study On InP-based Device And Metal Contact

In P based device and technology such as In P based metal-semiconductor conatct, In P/In Ga As photodectector and passivation technology are studied in this paper. The electrical characteristics of Ti W/p-In P Schottky barrier diode at different annealing conditions are systematically investigated and compared firstly. Barrier height(Φb0) and ideality factor(n) have been obtained from the thermal emission(TE) theory. The temperature dependency of barrier characteristics are interpreted by inhomogeneous model assuming a Gaussian distribution. The capacitance-voltage(C-V) characteristics are also measured, indicating that the barrier height Φc-v at different temperatures are higher than the barrier height obtained from I-V characteristics. This phenomenon can be explained by the influence of the interface states at relatively high frequencies.Then the C-V characteristics of Ti W/p-In P Schottky barrier diode are studied. The anomalous capacitance phenomenon can be attributed to the influence of interface states Nss and series resistance(Rs). Rs is calculated from the measured capacitance(Cm) and conductance(Gm) values. The corrected capacitance(Cc) and corrected conductance(Gc) are both obtained from the Cm and Gm values by taking into account Rs.In addition, we compare the passivation effects of PECVD and ICPCVD technology on In P surface. The I-V characteristics of Au/Si Nx/In P Metal-Insulator-Semiconductor(MIS) Schottky barrier diodes(SBD) with Si Nx deposited by different technology are investigated. The diode deposited by ICPCVD technology indicates the lower barrier heights and ideality factors. The interface density of ICPCVD deposited SBD is apparent lower than that of PECVD deposited SBD.Finally, the dark current and photocurrent of In Ga As/In P photodetector are studied. In order to optimize the detector layer structure, the device was simulated by software first and then fabricated according to the simulated results. The measured results are comparable with the simulated results. The results also show the smaller detector has lower dark current density, and the dominated mechanisms of dark current are discussed in the paper.