Supressing Segregation in Highly Doped Silicon Monolayers

30 June, 2016 @ 4:00 pm

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Abrupt dopant profiles and low resistivity are highly sought after qualities in the silicon microelectronics industry and, more recently, in the development of an all epitaxial Si:P based quantum computer. Previously, we have shown that increasing the dopant density by growing multiple layers is ultimately limited the formation of P-P dimers due to the segregation of dopants between multi-layers [1]. To suppress this segregation, and thereby creating more abrupt dopant profiles and higher active carrier densities, we investigated the application of thin room temperature grown silicon layers, so-called locking layers. Atom probe tomography and magneto-transport measurements show these locking layers are effective in suppressing segregation but reduce the active carrier density. However, we find that the careful application of a rapid thermal anneal can restore the active carrier density whilst maintaining an abrupt dopant profile. In this way we were able to achieve a fully activated P dosed layer that is confined within ~1nm and has a 3D dopant density of 2.5-3 atm. %, well beyond what was previously achieved for phosphorus dosed delta-layers.

  1. J.G. Keizer, S.R. McKibbin, M.Y. Simmons. The Impact of Dopant Segregation on the Maximum Carrier Density in Si:P Multilayers. ACS Nano, 9(7), pp7080-7084 (2015).


30 June, 2016
4:00 pm


Newton Building, UNSW
CQC2T Conference Room, Level 2, Newton Building J12, UNSW Kensington Campus NSW Australia


University of New South Wales