Measurement of Interface-Induced Optical Anisotropies of a Semiconductor Heterostructure: ZnSe / GaAs(100)

We have developed a simple procedure that enables in situ simultaneous measurement of the surface and interface anisotropies in semiconductor heterostructures. Optical anisotropies in ZnSe $/$GaAs(100) heterostructures grown by molecular beam epitaxy were measured in situ by reflectance difference spectroscopy (RDS). We show that a Se treatment of the clean GaAs surface forms an optically anisotropic subsurface layer that remains intact even after ZnSe overgrowth, while a Zn treatment results in a quite different interface RD response. The RD spectra of the Se- and Zn-terminated ZnSe surfaces are briefly discussed.