Semi-insulating porous SiC substrates

Abstract

Semi-insulating SiC substrates were fabricated on a base of porous silicon carbide made from 4H and 6H commercial SiC wafers. Porous SiC (PSC) layers, 3 µm in thickness, were made by surface anodization of SiC wafers and then impregnated with excessive Si from a sputtered SiO 2 film during thermal processing at 1200 • C. The processed structures were studied by Auger electron spectroscopy (AES), secondary ion mass spectroscopy (SIMS) and x-ray photoelectron spectroscopy (XPS). The Si/C ratio in the processed porous layers showed a measurable change from 1:1 to 2.3:1 due to the diffusion of Si from the SiO 2 film into the PSC layer during thermal processing. The value of specific resistivity achieved was found to be 5 × 10 11 cm at 470 K and 2 × 10 6 cm at 700 K, respectively, with an activation energy of resistivity of 1.53 eV. Preliminary evaluations of AlN films grown by HVPE on the prepared substrates are also presented.

Analysis of Erbium and Vanadium Diffusion in Porous Silicon Carbide

“…Diffusion in SiC is believed to proceed mostly via kickout or vacancy-related mechanisms [1][2][3][4][5]. Vacancies define many physical properties of SiC [7,8], and one of the current subjects of research is their contribution to the formation and properties of porous SiC, a material with many prospective applications [9,10]. The very formation of porous structure in SiC is believed to proceed via vacancy migration and clustering [11], and there are all grounds to believe that experimentally observed modification of the structure under thermal annealing [12,13] is also due to vacancy redistribution.…”

Stimulation of excitonic and defect-related luminescence in porous SiC

“…First of all blue emission had been investigated in PSiC layers [1]. Latter it was shown that PSiC is a promising medium for diffusion, which allows one to control electrical properties of bulk SiC material using diffusion doping [2]. Some prospective applications of SiC-based homoepitaxial device structures formed on PSC substrates with improved quality were reported [3].…”

Raman scattering investigation on porous SiC layers

“…Porous SiC (PSiC) has been around for a number of years as an object of interest for developing new technologies and applications. It has been shown that porous SiC is a promising medium for diffusion, which allows one to control electrical properties of bulk SiC material using diffusion doping [1]. Some perspective applications of SiC-based homoepitaxial device structures formed on PSiC substrates with improved quality were reported [2].…”