Postgrowth annealing effects of TiO2 thin films grown on InP substrate at low-temperature by metal-organic chemical-vapor deposition

Abstract

The structural and electrical properties of titanium dioxide (TiO2) thin films grown on n-type InP(100) substrate by low-pressure metal-organic chemical-vapor deposition have been studied with postannealing. The thin films of TiO2 were deposited at a low temperature of 350 °C using titanium isopropoxide and oxygen. After a postgrowth annealing by the rapid thermal annealing method at a temperature of 850 °C for 15 s, the TiO2/InP structure of only the anatase phase with (101) and (200) peaks was observed by x-ray diffraction analysis. No interface reaction between TiO2 and InP was detected by Auger electron spectroscopy depth profiling. From capacitance–voltage measurement of the Al/TiO2/n-InP structure, the interface density of states at midgap energy and the dielectric constant were approximately low 1012 eV−1 cm−2 at midgap energy and about 50, respectively.