Al-Dy/sub x/O/sub y/-n-InP [100] structure preparation and properties

Al-Dy/sub x/O/sub y/-n-InP structures with dysprosium oxide film prepared by two different methods have been studied. The Dy/sub x/O/sub y/ films with 40-120 nm thickness have obtained by Dy thermal evaporation in the O/sub 2/ environment (I) or in the vacuum (II) followed by thermal oxidation at 330-350/spl deg/C in a dry oxygen stream. It follows for analysis of the experiments that the breakdown field in the Al-Dy/sub x/O/sub y/(I)-n-InP structure E/sub br/ is 2.5/spl times/10/sup 6/ V/cm, the effective positive surface charge Q/sub ss/ is /spl sim/3/spl times/10/sup 11/ cm/sup -2/ and the surface state density N/sub it/ is 5/spl times/10/sup 11/ cm/sup -2/ eV/sup -1/. The C-V characteristics hysteresis is of injection type with the magnitude less than 0.3 V. The Al-Dy/sub x/O/sub y/ (II)-n-InP structure has surface charge magnitude Q/sub ss/ about /spl plusmn/1/spl times/10/sup 11/ cm/sup -2/ surface state density N/sub it//spl sim/1/spl times/10/sup 11/ cm/sup -2/ eV/sup -1/, ionic type hysteresis 1-3 V and E/sub br//spl sim/5/spl times/10/sup 6/.