Thermo-piezochemistry of InAs on GaAs(001)

We show that the large biaxial epitaxial stress (−5.3 GPa) of InAs on GaAs(001) strongly affects the chemical reaction between elemental In and As on the GaAs(001) surface at temperatures between 200 and 500 °C. In contrast to the reaction in the bulk at zero stress, solid InAs is not the sole reaction product, but rather a mixture of elemental and compound phases including liquid In and liquid InAs result. This view differs radically from the conventional view that solid InAs is the sole stable reaction product formed at the growing surface on a GaAs(001) substrate.