Co-doping of InxGa1−xAs with silicon and tellurium for improved ultra-low contact resistance

We report Te doping of bulk In0.53Ga0.47As up to 2.6×1019 cm−3 without saturation effects, and structural characterization and contact resistances between metal and epitaxial regrowth for four structures: Si doped and Si and Te co-doped n+ InAs regrowth on a 10 nm In0.53Ga0.47As channel, Si doped and Si and Te co-doped n+ In0.53Ga0.47As regrowth on a 7 nm In0.53Ga0.47As channel. We observe that the contact resistance for the Si doped and Si and Te co-doped n+ InAs regrowth on the 10 nm In0.53Ga0.47As channel is 9.9 Ω μm (3.9 Ω μm2) and 6.6 Ω μm (2.3 Ω μm2), and the contact resistance for the Si doped and Si and Te co-doped n+ In0.53Ga0.47As regrowth on the 7 nm In0.53Ga0.47As channel is 8.5 Ω μm (2.3 Ω μm2) and 6.8 Ω μm (1.9 Ω μm2). The improvement in contact resistance comes from improvements in electron mobility consistent with Te improving material quality as a surfactant.

► Te is an effective dopant of In0.53Ga0.47As from 2.1×1017 to 2.6×1019 cm−3. ► Heavy (mid- to low-1019 cm−3) co-doping of Te and Si improves carrier mobilities. ► Te as a co-dopant with Si lowers contact resistivity to In0.53Ga0.47As. ► Te as a co-dopant with Si lowers contact resistivity to InAs.