[TuP3A] Epitaxy and process

[TuP3A-16] Minimized Contact Resistivity to MOVPE-grown p-InGaAs:C

〇Jan Ebbert¹, Hao Zhang¹, Jonathan Abts¹, Fabian van Essen¹, Nils Weimann^1,2 (1. Dept. of Components for High Frequency Electronics, University of Duisburg-Essen (Germany), 2. Center for Nanointegration Duisburg-Essen (CENIDE) (Germany))

In this work, we investigated the resistivity of ohmic contacts to p-type InGaAs:C layers grown by Metalorganic Vapor Phase Epitaxy (MOVPE). High-resolution Electron Beam Lithography (EBL) combined with (Pt/Pd)/Ti/Pt/Au contacts allows a significant reduction in specific contact resistivity, enabling fabrication of high frequency InP DHBTs. Particular emphasis is placed on the influence of the InGaAs surface treatment, the thermal stability of the metal-semiconductor interface as well as the effect of the contact metal thickness on the electrical performance that is evaluated using the transfer length method (TLM). The optimizations result in ρ_c of (2.4±0.2)×10^-7 Ωcm² at a carrier concentration of ~ 2.0×10¹⁹ cm^-3 and place among the lowest reported values in this doping range.