High-quality GaAs Schottky diodes have been fabricated using a strained layer to improve the material quality. The epitaxial layer has been isoelectronically doped with In with a concentration of 4×1019 cm−3. The diodes fabricated on these layers show a reverse current of 100 pA–200 pA up to 50 V reverse-bias voltage at room temperature. The Schottky contact area was 7500 μm2 and the doping concentration 1×1016 cm−3. An excellent, reproducible ideality factor of 1.02 has been obtained over seven decades of forward current. Results of Schottky diodes fabricated on isoelectronically doped layers in comparison to conventionally fabricated devices are reported.