Integration and High-Temperature Characterization of Ferroelectric Vanadium-Doped Bismuth Titanate Thin Films on Silicon Carbide

Abstract

4H-SiC electronics can operate at high temperature (HT), e.g., 300°C to 500°C, for extended times. Systems using sensors and amplifiers that operate at HT would benefit from microcontrollers which can also operate at HT. Microcontrollers require nonvolatile memory (NVM) for computer programs. In this work, we demonstrate the possibility of integrating ferroelectric vanadiumdoped bismuth titanate (BiTV) thin films on 4H-SiC for HT memory applications, with BiTV ferroelectric capacitors providing memory functionality. Film deposition was achieved by laser ablation on Pt (111)/TiO 2 /4H-SiC substrates, with magnetron-sputtered Pt used as bottom electrode and thermally evaporated Au as upper contacts. Film characterization by x-ray diffraction analysis revealed predominately (117) orientation. P-E hysteresis loops measured at room temperature showed maximum 2P r of 48 lC/cm 2 , large enough for wide read margins. P-E loops were measurable up to 450°C, with losses limiting measurements above 450°C. The phase-transition temperature was determined to be about 660°C from the discontinuity in dielectric permittivity, close to what is achieved for ceramics. These BiTV ferroelectric capacitors demonstrate potential for use in HT NVM applications for SiC digital electronics.

High-Temperature Recessed Channel SiC CMOS Inverters and Ring Oscillators

“…Of these transistors and circuit families, the static complementary MOSFET (CMOS) circuit family offers high input impedance, high fan-out, rail-to-rail swing output, low static power consumption, dense and simple digital circuit design and compatibility with all state-of-theart memory technologies. SiC CMOS together with integrated ferroelectric memory devices [16], [17] could give non-volatile memory operational at high temperatures. The state-of-the-art SiC NMOS devices uses nitridation in either N 2 O or NO to achieve high channel mobility (µ n ), typically in the range 25-35 cm 2 /Vs [18], [19].…”