Differential hall characterization of shallow strained SiGe layers

A Differential Hall Effect method has been developed that allows to determine of the dopant activation level of SiGe alloys in the surface region. The technique is first optimised in terms of etch rate (∼ 1Å/min), surface roughness, strain and stoichiometry stability during etch. We then show that this DHE method allows to experimentally access the dopant activation of ultra-shallow surface layers of less than 0.5 nm.