Competition of terrace and step-edge sputtering under oblique-incidence ion impact on a stepped Pt(111) surface

Abstract

a b s t r a c tUsing molecular-dynamics simulation, we study the sputtering of a Pt(1 1 1) surface under oblique and glancing incidence 5 keV Ar ions. For incidence angles larger than a critical angle # c , the projectile is reflected off the surface and the sputter yield is zero. We discuss the azimuth dependence of the critical angle # c with the help of the surface corrugation felt by the impinging ion. If a step exists on the surface, sputtering occurs also for glancing incidence # > # c . We demonstrate that for realistic step densities, the total sputtering of a stepped surface may be sizable even at glancing incidence.

Glancing ion incidence on Si(100): Influence of surface reconstruction on ion subsurface channeling

“…In previous work, 7,8,23,24 we determined that ions interact with the step-and can enter a subsurface channel-only if their impact point is within a region −x c < ξ < 0; that is, not farther than the critical distance x c away from the step edge. For a flat terrace, x c is given by a simple geometrical criterion, 25…”

Sputtering at grazing ion incidence: Influence of adatom islands

“…The cases of a single isolated adatom ͑N =1͒ and of a densepacked surface step ͑corresponding to N = ϱ͒ have been simulated previously. [1][2][3][4]6,10,21 The adatoms are put on stable fcc sites on top of the crystallite. The island position, as well as that of all surface atoms are relaxed.…”

“…The effect of surface steps has been analyzed in detail. [1][2][3][4] It was shown that if the ion impact point is in the vicinity of an ascending step edge, an ion may sputter as many atoms as for normal incidence. The sputter yield of a stepped surface is thus primarily governed by the step density.…”

“…We note that we investigated previously the effects of a varied incidence angle on sputtering from surface steps and found qualitatively similar results. For the 5 keV Ar impact at 83°i ncidence onto the Pt ͑111͒ surface, where already a considerable body of information on the sputtering behavior both from experiment and simulation is available, [1][2][3][4][5][6][7] we perform dedicated experiments. Here, the Pt surface is initially covered by Pt adatom islands which have been deposited on the surface prior to ion bombardment.…”