Angular dependence of preferential sputtering and composition in aluminum-copper thin films

Journal Article · Mon Sep 05 00:00:00 EDT 1988 · Appl. Phys. Lett.; (United States)

DOI:https://doi.org/10.1063/1.100090· OSTI ID:7135788

Rudeck, P J; Harper, J M.E.; Fryer, P M

The copper concentration in aluminum-copper alloys can be altered by ion bombardment during film deposition. We have measured the sputtering yields of aluminum and copper in Al-Cu alloys as a function of the Cu concentration (5--13 at. %) and the angle of ion incidence (0/sup 0/--40/sup 0/ from normal). During deposition, the films were partially resputtered by 500 eV Ar/sup +/ ion bombardment from a Kaufman ion source. We found that the Cu sputtering yield decreases by up to a factor of 10 in the alloy, relative to elemental Cu. The Al sputtering yield remains close to the elemental value. The net effect is a strong preferential sputtering of Al relative to Cu, which enhances the Cu concentration in an ion-bombarded film. The Al/Cu sputtering yield ratio for normal incidence ion bombardment ranges from 3 to 5 as a function of Cu concentration. This ratio decreases with increasing angle of incidence to as low as 2 for 40/sup 0/ incident ions. However, since a higher fraction of the film is resputtered from a sloping surface, a higher Cu concentration is found on a sloping surface relative to a flat surface. These results show that the film composition will vary as a function of the surface topography.

• Research Organization: IBM Watson Research Center, Yorktown Heights, New York 10598
• OSTI ID: 7135788
• Journal Information: Appl. Phys. Lett.; (United States), Vol. 53:10
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM
SPUTTERING
ALUMINIUM BASE ALLOYS
CHEMICAL COMPOSITION
ION COLLISIONS
TOPOGRAPHY
ARGON IONS
COLLISIONS
COPPER
COPPER ALLOYS
EV RANGE 100-1000
MORPHOLOGY
THIN FILMS
ALLOYS
ALUMINIUM ALLOYS
CHARGED PARTICLES
ELEMENTS
ENERGY RANGE
EV RANGE
FILMS
IONS
METALS
TRANSITION ELEMENTS
656003* - Condensed Matter Physics- Interactions between Beams & Condensed Matter- (1987-)