(50a) Dopant Selective Photoelectrochemical Etching of SiC
AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
Materials Engineering and Sciences Division
Area Plenary: Leaders in Electronic and Photonic Materials (Invited Talks from Industry and Academia)
Tuesday, November 7, 2023 - 12:35pm to 1:10pm
Single crystalline 4H-SiC is a wide-gap semiconductor with optical properties that are poised to enable new applications in MEMS and quantum devices. A number of key hurdles remain with respect to the micro and nano-fabrication of SiC to prepare precise photonic structures with nanometer-scale precision. These challenges include development of a fast, scalable etching process for SiC capable of producing a sub-nanometer roughness semiconductor surface while simultaneously reducing the total thickness variation across a wafer. Our investigation into UV photoelectrochemical processing of SiC reveals high dopant-type selectivity and the advantage of multiple etch stops to reduce layer thickness variation. We demonstrate dopant-type selectivities >20:1 using a single step and a >100x reduction in surface variation by combining two etch stops. Moreover, the etch rate is fast (>4 μm/h) and the etched surface is smooth (â¼1 nm RMS). These results demonstrate a scalable path to the fabrication of precise nanoscale SiC structures and electronic devices that will enable the next generation of MEMS and photonic quantum devices.