title: Planar InAs photodiodes fabricated using He ion implantation.
abstract: We have performed Helium (He) ion implantation on InAs and performed post implant annealing to investigate the effect on the sheet resistance. Using the transmission line model (TLM) we have shown that the sheet resistance of a p⁺ InAs layer, with a nominal doping concentration of 1x10¹⁸ cm⁻³, can increase by over 5 orders of magnitude upon implantation. We achieved a sheet resistance of 1x10⁵ Ω/Square in an 'as-implanted' sample and with subsequent annealing this can be further increased to 1x10⁷ Ω/Square. By also performing implantation on p-i-n structures we have shown that it is possible to produce planar photodiodes with comparable dark currents and quantum efficiencies to chemically etched reference mesa InAs photodiodes.
authors.affiliation: Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, UK. i.sandall@sheffield.ac.uk
authors.forename: Ian
authors.initials: I
authors.lastname: Sandall
authors.forename: Chee Hing
authors.initials: CH
authors.lastname: Tan
authors.forename: Andrew
authors.initials: A
authors.lastname: Smith
authors.forename: Russell
authors.initials: R
authors.lastname: Gwilliam