Lattice-matched single-crystalline dielectric films (Ba<i>x</i>Sr1−<i>x</i>F2) on InP(001) grown by molecular-beam epitaxy

Abstract

We report lattice-matched single-crystalline dielectric films on a III–V compound semiconductor InP(001) substrate by molecular-beam epitaxial growth of BaxSr1−xF2. We used two methods to grow mixed fluoride films: two separate beams of BaF2 and SrF2 as well as a single beam of BaxSr1−xF2. In situ reflection high energy electron diffraction shows the parallel epitaxial relationship, BaxSr1−xF2(001)∥InP(001) and BaxSr1−xF2[110]∥InP[110]. The films were studied by double-crystal x-ray diffractometry for lattice parameters and Rutherford backscattering/channeling for compositions and crystallinity. Transmission electron microscopy shows that the films are single crystalline. Preliminary electrical results are also mentioned. Lattice-matched single-crystalline dielectric films can be important for epitaxial metal–insulator–semiconductor as well as semiconductor–insulator–semiconductor structures in a variety of device applications.