MORPHOLOGY OF EPITAXIAL SRF2 FILMS ON ATOMICALLY MODIFIED INP(100)

This paper presents the first results of our molecular beam epitaxy (M BE) experiments on the growth of SrF2 on InP(100) using synchrotron ra diation photoelectron spectroscopy (SRPES). Two different ways of prep aring the InP surface were used: ex situ HF etching and in situ As tre atment. Whereas HF etching provided a clean but rough surface, As trea tment led to a flat InP surface with a two-monolayer thick InAs overla yer. The SrF2 grew epitaxially even at room temperature (RT). There wa s a significant difference in surface roughness of 50 angstrom thick f ilms grown on these two InP surfaces at RT and then annealed at 500-de grees-C for 10 min. The film deposited on the HF etched InP surface ha d a roughness of 1.8 angstrom, which is rather flat, whereas the film deposited on the As-treated surface had a roughness of 4.5 angstrom, w hich is rather rough. These roughnesses were determined by atomic forc e microscopy (AFM). A possible growth model is discussed.