Investigation Of Highly Charged Ar～(q+), Pb～(q+) Sputtering On The Surface Of Si, Cu W Target

It has brought a lot of interest to do some research on interaction of slow highly charged ions (SHCI) with solid surface, during last 20 years, such as the neutralization process of projectile, X-ray, Auger electron, and surface atom sputtering. Many useful conclusions have been got both in experiment and theory way. For its huge potential energy, SHCI may remove quantity of atoms from solid surface. So, SHCI with low kinetic energy could lead to nanoscale modification in solid surface, yet not causing any distortion in the solid. Surface atom sputtering caused by SHCI is a valuable research at present.Experiment about SHCI Ar^q+ (E_k=20-320keV, q=8, 11, 13, 15, 16), Pb^q+(E_k=80-720keV, q=20, 24, 30, 32, 35, 36) interacting with clean Si, Cu and W solid target was performed at ECR platform in Institute of modern physics, the Chinese academy of science. The targets were cleaned with series of chemical and physical methods. Relative yield without negative particles was detected with incident angle being varied from 15°to75°(surface atoms took up nearly 99.9% of the whole detected particles). In details, the experiment was carried out with the projectile of(a) Ar^q+(E_k=160keV,q=8,11,13,15,16)(b) Ar¹⁶⁺(E_k=96,112,128,144,160,176,208,240,288,320keV)(c) Ar⁺(E_k=20keV)(d) Pb^q+(E_k=400keV, q=20,24,30,32,35,36)(e) Pb³⁶⁺ (E_k=216,252,288,324,360,432,504,576,648,720keV)(f) Pb⁴⁺(E_k=80keV) interacting with Si, Cu, W solid target.The experimental results offered a lot of information. (1) Surface atom potential sputtering was not very distinctive while Ar^q+ interacting with Si, Cu, W surface, and no explosion happened in the target surface, when both Ar^q+ and Pb^q+ interacting with Si, Cu, W surface. (2) A resonant velocity region of incident ion (0.30v_Bohr < v < 0.40v_Bohr) was found which did not depend on target material, and in this region the sputtering yield could become larger. (3) The yield depended on nuclear stopping power closely, increased with the nuclear stopping power growing, and especially the yield was proportional to nuclear stopping power while projectile Ar¹⁶⁺ interacting with Si solid target.