Electrical properties of solid-solution SrZr$_{\mathrm{x}}$Ti$_{\mathrm{1-x}}$O$_{\mathrm{3}}$ grown epitaxially on Ge by molecular beam epitaxy

The epitaxial growth of crystalline oxides on semiconductors enables new functionalities to be introduced to semiconductor devices. In particular, dielectric and ferroelectric oxides grown epitaxially on semiconductors provide a pathway to realize ultra-low power logic and memory devices. Here we present electrical characterization of solid-solution SrZr$_{\mathrm{x}}$Ti$_{\mathrm{1-x}}$O$_{\mathrm{3}}$ grown epitaxially on Ge through oxide molecular beam epitaxy. SrZr$_{\mathrm{x}}$Ti$_{\mathrm{1-x}}$O$_{\mathrm{3}}$ is of particular interest since the band offset with respect to the semiconductor can be tuned through Zr content x. We will present current-voltage, capacitance-voltage and piezoforce microscopy characterization of SrZr$_{\mathrm{x}}$Ti$_{\mathrm{1-x}}$O$_{\mathrm{3}}$ -Ge heterojunctions. In particular, we will discuss how the electrical characteristics of SrZr$_{\mathrm{x}}$Ti$_{\mathrm{1-x}}$O$_{\mathrm{3}}$ -Ge heterojunctions evolve with respect to composition, annealing and film thickness.