PLASMA-CONTROLLED SELECTIVE AREA GROWTH OF GAAS BY ELECTRON-CYCLOTRON RESONANCE PLASMA-EXCITED MOLECULAR-BEAM EPITAXY (ECR-MBE)

Selective growth of GaAs on a GaAs substrate with a Si3N4-patterned mask has been controlled at 630°C by plasma conditions, using the electron-cyclotron resonance plasma-excited molecular-beam epitaxy (ECR-MBE) method. Increasing the microwave power or negative DC bias applied to the substrate, indicative of an increase in the impinging energy of charged particles on the substrate surface, improved the selectivity of the growth. The ratios of the widths of unmasked and masked areas did not affect the growth rate in the unmasked areas. Increasing the microwave power reduced the growth rate in the unmasked areas. We discuss the growth kinetics and show that these results support our contention that a plasma-enhanced desorption process of impinging atoms from the Si3N4 surface plays an important role in the selective growth of GaAs. © 1990.