Sputtering of copper by 20 keV Noble gas ions at low temperatures

Journal Article · Wed Jan 01 04:00:00 EST 1964 · Physica

DOI:https://doi.org/10.1016/0031-8914(64)90209-5· OSTI ID:4054235

Flutt, J. M.; Snoek, C.; Kistemaker, J.

Single crystals of copper and polycrystalline copper were bombarded at normal incidence with 20-kev Ar/sup +/ and Ne/sup +/ ions at various temperatures between 30 and 320 deg K. The sputtering ratio, S, for Ar/sup +/ on polycrystalline targets as well as on monocrystalline surfaces showed no temperature dependence within the accuracy of measurements between 80 and 350 deg K. This is attributed to the surface contamination caused by Ar itself, especially at lower temperatures. Bombardment with Ne/sup +/ in the temperature range between 30 and 350 deg K on polycrystalline Cu and on (111) and (100) single crystal surfaces showed a very pronounced temperature dependence below 200 deg K. Apparently Ne diffuses through Cu lattices so easily that no serious sunface contamination or lattice distortion arises. An explanation is given on the basis of internal focusing mechanisms inside the crystal. A steep decrease in S observed below 150 deg K is related to the diffusion of the so-called B interstitials in the Cu lattice. On this assumption, the measurements yield an activation energy of (0.29 plus or minus 0.02) ev for the diffusion process. A second steep decrease of the sputtering coefficient below 50 deg K can be due to the decreased diffusion of A interstitial copper atoms (activation energy 0.1 ev). A sharp rise in S going from about 100 to 50 deg K probably corresponds to an increasing saturation of the copper lattice with Ne. This was verified by measurement of the gas content present in the targets following bombardment.

• Research Organization: F.O.M.-Laboratorium voor Massascheiding, Amsterdam
• Sponsoring Organization: USDOE
• NSA Number: NSA-18-016673
• OSTI ID: 4054235
• Journal Information: Physica, Journal Name: Physica Journal Issue: 1 Vol. 30; ISSN 0031-8914
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ARGON
CONTAMINATION
COPPER
CRYSTALS
DEFECTS
DIFFUSION
ENERGY
ENERGY RANGE
EXCITATION
INTERSTITIALS
IONS
IRRADIATION
LATTICES
LOW TEMPERATURE
MEASURED VALUES
MONOCRYSTALS
NEON
PHYSICS
RARE GASES
SPUTTERING
SURFACES
TARGETS
TEMPERATURE