For the first time, an epitaxial beryllium oxide (BeO) film was grown on 4H silicon carbide (4H-SiC) by atomic layer deposition (ALD) at a low temperature of 250 °C. The BeO film had a large lattice mismatch with the substrate (>7–8%), but it was successfully grown to a single crystal by domain-matching epitaxy (DME). The bandgap energy, dielectric constant, and thermal conductivity properties of crystalline BeO are suitable for power transistors that require low leakage currents and fast heat dissipation in high electric fields. Physical characterization confirmed the single-crystalline BeO (0 0 2). Raman analysis showed that the E 1 and A 1 phonon modes of ALD BeO were intermixed with the E 2 and A 1 phonon modes of SiC, resulting in a significant increase in phonon intensity. After heat treatment at a high temperature, a small amount of SiO 2 interfacial oxide was formed but the stoichiometry of BeO was maintained. From the capacitance-voltage (C-V) curves, we obtained a dielectric constant of 6.9 and calculated a low interface trap density of 6 × 10 10 cm −2 ·eV −1 using the Terman method at E c -E t = 0.6 eV. The high bandgap, thermal conductivity, and excellent crystallinity reduced the dangling bonds at the interface of BeO-on-SiC.
Bibliographical noteFunding Information:
This research was supported by the MSIT (Ministry of Science and ICT), Korea, under the “ICT Consilience Creative Program” ( IITP-2018-2017-0-01015 ) supervised by the IITP (Institute for Information & communications Technology Promotion), by Korea Electric Power Corporation. (Grant number3): R18XA06-03 , and by the Basic Science Research Program through the NRF ( 2015R1A6A1A03031833 ). CWB, JHY, and ESL are grateful to the Institute for Basic Science (IBS-R019-D1) as well as the BK21 Plus Program funded by the Ministry of Education and the National Research Foundation of Korea for their support. Dr. Jae-Gil Lee provided assistance with electrical characterization using the Terman method, and the authors are grateful for his technical support.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films