Microwave performance of GaAs MESFET's with AlGaAs buffer layers—Effect of heterointerfaces

Field-effect transistors consisting of GaAs active layers and Al
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Ga
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As buffer layers with abrupt, graded-bulk, and graded superlattice heterointerfaces were fabricated and compared to GaAs buffer transistors. Microwave measurements showed that a good interface is obtained in the graded superlattice interface structure and that there is a small improvement in gain (1-2 dB) over the GaAs buffer structure.