n-type ion implantation doping of AlxGa1−xAs (0⩽x⩽0.7)

Abstract

Si-implant activation characteristics in AlxGa1−xAs for Al compositions of 0%–70% AlAs are presented for doses of 5.6×1012 and 2.8×1013 cm−2 at 100 keV. For both doses, the effective activation efficiency (ηeff) is relatively constant from 0% to 20% AlAs (ηeff=64% for 5.6×1012 cm−2 and 37% for 2.8×1013 cm−2 for 20% AlAs), goes through a minimum at 35% AlAs (ηeff=6.6% for 5.6×1012 cm−2 and 2.5% for 2.8×1013 cm−2), and then increases towards 70% AlAs (ηeff=52.8% for 5.6×1012 cm−2 and 31.1% for 2.8×1013 cm−2). The results are explained based on the compositional dependence of the ionization energy and conduction band density-of-states of AlGaAs. The effects of P coimplantation is also studied but demonstrates no significant enhancement of the activation efficiency of Si implantation for 0%–70% AlAs. Finally, data are presented for Se implantation in Al0.2Ga0.8As with a maximum effective activation efficiency of 5.6% achieved.

Ion Implantation For High Performance Ill-V Jfets And Hfets

“…The results for InGaP are particularly important when compared to Si-implanted AlGaAs with the same energy gap at 35% AlAs. Si-implantation in AI,,,G~~,As is limited by the high donor ionization energy (-160 meV) associated with the DX level and relatively low conduction band density-of-state at this composition [39]. Therefore, InGaP is extremely attractive as an alternative to AlGaAs in n-type doped structures whether they are formed by implantation or epitaxially grown due to the shallow donor level.…”