Lattice distortion near InGaP compound semiconductor surface due to surface treatment of bias sputtering

Strain fields near InGaP surfaces due to bias sputtering are affected by the bias voltage used in this surface-cleaning treatment. Measured rocking curves of an InGaP113 reflection under grazing X-ray incidence conditions consisted of a main peak and broad sub peaks. The shape of the broad sub peaks was due to a compositional fluctuation near the subsurface. Changes in the main peak versus bias voltage curves indicate that bias sputtering introduces a tensile strain to the InGaP surface. Furthermore, changes in the sub peak versus supplied bias voltage curves indicate that excessive sputtering generates a heavy compositional fluctuation near the InGaP subsurface. In conclusion, based on the measured strain and compositional fluctuation, a heavy compositional fluctuation generally causes a large tensile strain near the InGaP surface.