Probing the ex situ morphology of Ge islands on Si(001): AFM and XPS inelastic peak shape analysis

The dependence of morphology on growth temperature for Ce islands on Si(001 ) is studied ex situ using XPS inelastic peak shape analysis and atomic for ce microscopy (AFM). A systematic study is performed with temperatures of 2 00 degreesC, 550 degreesC and 700 degreesC and Ge nominal coverages of 5, 1 0 and 20 Angstrom. By peak shape analysis of the Ge 2p and Si KLL spectra, islanding is found and the average island morphology is characterized quant itatively. The island morphology shows systematic trends with both temperat ure and Ge coverage. At fixed Ge dosage, increasing substrate temperature l eads to taller and narrower islands, whereas for fixed temperatures both th e island height and width increase with increasing Ge dosage. By AFM, the i sland morphology is resolved laterally and the size distribution of islands is found to depend strongly on temperature. Correlating the AFM and XPS re sults shows that they are complementary and consistent. Oxidation of the na nostructures is investigated by core-level chemical shifts and the in-depth distribution of oxygen is determined. There is substantial Ge oxidation an d essentially no Si oxide is found. Copyright (C) 2001 John Wiley & Sons, L td.