Area-selective epitaxy of GaAs by migration-enhanced epitaxy with As2 and As4 arsenic sources

We demonstrate area-selective epitaxy by migration-enhanced epitaxy with As2 and As4 as arsenic sources. The distinct whisker structure growing in [1 1 1]B direction is obtained when employing As2 as an arsenic source, while (1 1 1)B facet is formed with As4. The difference in the facet formation can be explained by the formation of As-trimer, which significantly reduces the growth rate of the (1 1 1)B surface. With As2, area-selective epitaxy can be achieved at lower arsenic pressure condition, where less As-trimers are formed. Therefore, growth in the [1 1 1]B direction is enhanced.