Fabrication of step-edge structures on R-plane sapphire using a selective wet etch process

P. LEVY, S. NICOLETTI, L. CORRERA, M. CERVERA, M. BIANCONI, F. BISCARINI, F. CORTICELLI AND E. GABILLI

IL NUOVO CIMENTO

© Societa Italiana di Fisica

Lugar: Milan; Año: 1997 vol. 19 p. 1389 - 1395

0393-4578

Summary. - With the aim of using some well established techniques in the planartecnology of silicon for the fabrication of high- Tc grain boundary based junctions, weinvestigated a process suitable for the realisation of step-edge on R-plane sapphiresubstrates. Step-edges were prepared by exposing a photolitographically definedarea to Ar+ ion implantation. The damaged area was selectively removed bydifferent wet etching processes. With this technique we were able to produce 150 nmheight steps, 30°-45° slope. The surface roughness on both sides of the step was thesame as that of the virgin sustrate. The influences of dose, angle of implant, etch rateand related main feature of the process are discussed.PACS. 74.76 - Superconducting films.