Ultra-High Throughput of GaAs and (AlGa)As Layers Grown by Molecular Beam Epitaxy (MBE) with a Specially Designed MBE System

The ultra-high throughput of extremely uniform GaAs and (AlGa)As layers with excellent surface morphology can be realized by MBE with a new MBE system designed for both a drastic increase of the throughput and a reduction of the surface defect density. The simultaneous growth of seven 5-cm-dia. epiwafers can be achieved with a thickness variation of less than 2% by optimizing the effusion cell geometry. A computer-controlled growth sequencer and a newly developed source recharging system are incorporated for automatic growth, and operated continuously day and night without venting the growth chamber even during source recharging. The surface defect density has been reduced to less than 50/cm 2 by the introduction of a modified Ga cell and a face-down sample-transfer system. This system allows the growth of nearly 100 GaAs FET or HEMT wafers each day (24 hr). The devices constructed from these wafters showed excellent performance.