Molecular beam epitaxial GaAs-AlxGa1-xAs heterostructures for metal semiconductor field effect transistor applications

Abstract

High‐quality GaAs‐Al_xGa_1‐xAs heterostructures for metal semiconductor field effect transistor (MESFET) applications have been grown by molecular beam epitaxy. 0.5‐μm‐thick n‐type GaAs active layers with free‐carrier concentrations ∼1.1×10¹⁷ cm⁻³ and room‐temperature electron mobilities ∼4400 cm² V⁻¹ sec⁻¹ were routinely obtained on top of undoped Al_xGa_1‐x As (x∼0.4) buffer layers. MESFET’s fabricated on these layers showed approximately 2000‐Ω‐mm output resistance.