Ultra‐sharp boron interfaces for delta doped diamond structures

Delta doping of diamond constitutes a very promising route to fabricate novel generation of high power and high frequency electronic devices. However, the achievement of abrupt interfaces between highly boron doped and undoped layers requires the shortest residence times of reactive species in the substrate vicinity. We report here on an innovative gas injection system especially designed to reduce this residence time. This technique was applied to fabricate sharp rising and decaying boron interfaces. According to SIMS profiles, the sharpest profiles were obtained on decaying interfaces exhibiting doping gradients close to 1.5 nm per decade over five decades of boron concentrations, namely from 10¹⁶ to 10²¹ atoms/cm³. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)