Sputtering from a liquid phase Ga-In eutectic alloy

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5818554

Hubbard, K M

Sputtering experiments were performed with a liquid-phase Ga-In eutectic alloy target. The bulk composition of the eutectic alloy is 16.5 at% In, but thermodynamic surface-segregation results in a surface monolayer of >94 at% In. Angular distributions and partial sputtering yields were measured for 3, 25, and 50 keV Ar{sup +} bombardment. Comparison of the sputtered-flux composition with the alloy surface composition profile allowed calculation of the fraction of sputtered atoms originating from the first atomic layer. The result was found to be {approx}0.87 {plus minus} {sup 0.05}{sub 0.03} at 25 and 50 keV, and increased to 0.94 {plus minus} {sup 0.06}{sub 0.04} at 3 keV. The increase may reflect a decrease in the average energy of recoil atoms within collision cascades, because fewer second layer recoil atoms would be able to penetrate the surface layer. Low-energy (4-6 eV) secondary-ion mass spectra were measured for Ne{sup +}, Ar{sup +}, Kr{sup +}, and Xe{sup +} bombardment in the energy range of 25-250 keV. The intensity ratio I(In{sup +})/I(Ga{sup +}) was found to be independent of projectile energy, as expected from the collision cascade theory of sputtering. However, a systematic increase, of {approx}25%, was observed as the projectile mass was increased from that of Ne to that of Xe. This was estimated to correspond to an increase of 5% in the fraction of sputtered atoms originating from the first atomic layer. Molecular/atomic ion yield ratios were measured for 25-250 keV Ne{sup +}, Ar{sup +}, Kr{sup +}, and Xe{sup +} bombardment of Ga and In elemental standards, and were found to be nearly independent of both projectile energy and mass. A published theory based on the recombination of independently sputtered neutral constituents predicts a relative yield proportional to the sputtering yield.

• Research Organization: Yale Univ., New Haven, CT (USA)
• OSTI ID: 5818554
• Country of Publication: United States
• Language: English

Related Subjects

656003* -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOY SYSTEMS
ALLOYS
ANGULAR DISTRIBUTION
ARGON IONS
BINARY ALLOY SYSTEMS
CATIONS
CHARGED PARTICLES
COLLISIONS
COMPARATIVE EVALUATIONS
DISTRIBUTION
ELEMENTS
ENERGY RANGE
FLUIDS
GALLIUM ALLOYS
INDIUM ALLOYS
IONS
KEV RANGE
KEV RANGE 01-10
KEV RANGE 10-100
KEV RANGE 100-1000
KRYPTON IONS
LIQUID METALS
LIQUIDS
MASS SPECTRA
METALS
NEON IONS
SPECTRA
SPUTTERING
XENON IONS