PHYSICAL-PROPERTIES OF Y2O3 FILMS FABRICATED BY THE REACTIVE IONIZED CLUSTER BEAM DEPOSITION TECHNIQUE

Heteroepitaxial Y2O3 films On Si(100) were grown by the ionized cluste r beam (ICE) deposition technique. The composition of the deposited fi lm was investigated using Rutherford backscattering spectroscopy. The composition ratios of the Y2O3 films changed with changes in the depos ition conditions. In the case of the film which was fabricated under o ptimum conditions, the ratio of Y to O was 1 to 1.55. The crystal orie ntational relation of the films deposited on a Si (100) substrate was investigated by using reflection high-energy electron diffraction. We found that the orientation of the deposited film changed mainly due to changes of the substrate temperature and the cluster acceleration ene rgy. Y2O3 films were epitaxially grown above 800 degrees C without acc eleration, and heteroepitaxial growth of Y2O3 films on Si(100) substra tes was possible with a 5-kV acceleration voltage above 650 degrees C. The epitaxial relationship between Y2O3 and Si(100) was Y2O3(110)//Si (100) and Y2O3[110]//Si[100] or Y2O3(110)//Si(100) and Y2O3[100]//Si[1 00]. The I-V characteristics of Al/Y2O3/Si metal-insulator-semiconduct or devices were investigated. After thermal annealing in an oxygen amb ient, the measured value of the breakdown strength was more than 3 MV/ cm and the leakage current was lower than 1 x 10(-10) A/cm(2).