MEASUREMENT OF SURFACE STRESS DURING EPITAXIAL-GROWTH OF GE ON ARSENIC TERMINATED SI(001)

Using a simple optical technique, we have measured the change in surface stress of Si(001) during the adsorption of a monolayer of arsenic and during the epitaxial growth of germanium with arsenic as a surfactant. Tensile surface stress increases nearly linearly with arsenic coverage until it attains a value of 1400 +/- 100 dyn/cm at a full monolayer. During germanium deposition on an arsenic terminated surface, (compressive) surface stress increases at a rate of -1270 dyn/cm per ML (monolayer) between 3 and 8 or 9 ML, the known critical film thickness for defect formation; the stress per monolayer found above 10 ML is substantially smaller.