Characterization of Semiconductor Device Processing Etchant Solutions for GaAsand p+ GaAs Layers Employed in AlxGa(1-x)As/GaAs Modfets and Related Heterojunction Devices

摘要

The etch rates of GaAs, p+ GaAs, AlxGa1-xAs and n-AlxGa1 -xAs were examined with respect to solution composition and pH in an effort to determine a solution that will selectively etch only GaAs from the area between the gate-and-source and gate-and-drain of a p+GaAs/AlxGa1-xAs/GaAs Modulation-Doped Field-Effect Transistor. The measurement of the etch rates for GaAs and AlxGa1-xAs was approached from different perspectives. First, a method based upon corrosion testing, that determines etch rates from weight loss, was attempted. A second method involved the use of a Fischione Twin-Jet Electropolisher. Both techniques were verified against a known method of etch depth measurement using a profilometer. A selective etch would also be useful in the last step of the fabrication process of the (ES)MODFET. Theses, Gallium arsenides, Aluminum gallium arsenide. (mjm)