Collision cascade theory predicts that the angular distribution of sputtered atoms should have a cos e. At the top of the target chamber is a rotating inlet which holds the collector-foil apparatus. There are four sets of collector plates which can be positioned over the target by means of a rotary input.
A cavity in the main body of the target holder contains an Analog Devices temperature transducer. The heating filament is encapsulated in a Macer block that completely shields the target holder from the filament and prevents the passage of the thermal electrons from the filament to the holder. This circuit can maintain the temperature of the target structure within ±0.01°C for 24 hours without noticeable drift.
This twelve-sided holder can be rotated to position any collector foil in the path of the incident beam. This screen also helps in suppressing secondary electrons thrown by the incident beam from the target.
PROCEDURE A. Targets
After the dry ice pack was kept for 24 hours, the temperature of the target holder was -20°c. These tabs were in good electrical contact with the rest of the collector paper holder assembly. However, it was impossible to guarantee the relative position of the collector vanes to the browsing target better than.
Consequently, the collector foils mounted on the target container were not in the center of the. First, the cleanliness of the target surface does not change during the sputtering. Second, the probability of sticking stuck gallium atoms on the collector foils does not change as gallium accumulates on the surface of the foils.
Note that the Ar+ energy is reported as 14.7 keV due to the electron suppression on the target.). First, the ratio of indium yield to gallium yield for the 15 keV Ar+ is 28 times higher than would be expected based on the target stoichiometry. E and m are the energy and mass of the incident projectiles, and M is the mass of the target atoms.
Figures 22 and 23 show the broadening of the indium distribution for the target which was gradually raised.
DISCUSSION
The refraction relation above assumes that the component of the moment of an atom parallel to the surface remains constant as the atom crosses the surface boundary. Furthermore, most of the surface segregations were observed by Auger analysis, which typically did not have a depth resolution of no better than 5 monolayers. ISS analysis of the liquid eutectic showed a concentration of indium in the first monolayer.
Let x represent the fraction of sputtered atoms coming from the first monolayer of the target surface. The errors in the above values for x are due to the uncertainty in the exact composition of the first monolayer. The error in f is relatively small since any systematic errors in the measurement of the sputter yields should cancel out in the determination of f.
However, the effects observed here would be negated if the intensity of the incident radiation were high enough to cause evaporation (Krutenat and Gesick, 1970). A final word must be said about the formation of indium crystallites on the surface of the solid eutectic. The surface of the target forms an angle of 45° with the plane of the diagram and is positioned to intercept the vertical ion beam.
This opening is grounded, and its width determines the energy resolution of the analyzer, which is 0.5%. However, the energy resolution of the incident beam, nonzero beam spot diameter, and inelastic scattering also contribute to the peak widths. After ions of the appropriate energy pass through the analyzer (Es = 10 x V, where Vis is the analyzer voltage), they hit the input of the channeltron detector, which is biased to -2800 v.
The rest of Figure 33 is devoted to the pulse handling electronics for the pulses coming out of the channeltron detector. Gabta, Emission of L photons from sputtered atoms as a function of phase transition in targets", paper presented at the Ninth International Conference on Atomic Collisions in Solids, Lyon, 6-10 July 1981. B is taken by fitting the differential scattering is given by dS/dQ in a function of the form A cosB 9 where 9 is the angle with respect to the target normal.
B is obtained by fitting the partial differential sputter yield to a function of the form A cosB e. The target container rotates about an axis perpendicular to the plane of the diagram.
AMMETER I
The normalized differential sputtering efficiency versus a for the low-dose solid gallium run from Table 2. The normalized differential sputtering efficiency versus e for the high-dose solid gallium run from Table 2. Although sputtering efficiency could not be obtained for this run due to poor Ar+ beam current integration , is the angular division.
Rutherford backscattering spectrum of a graphite foil collecting sputtered atoms from a liquid gallium-indium eutectic target. The Rutherford cross section for indium is 2.5 times as large as the cross section for gallium. Compare the angular distribution with the individual distribution of the same target in Figure 15.
Rutherford backscatter spectrum of a graphite sheet that collected sputtered atoms from the first run on the rapidly frozen eutectic target. Rutherford scattering spectrum of a graphite sheet that collected sputtered atoms from the second run on the rapidly frozen eutectic target. Rutherford scattering spectrum of a graphite sheet that collected sputtered atoms from the third run on the rapidly frozen eutectic target.
Composition of sputtered material from gallium-indium eutectic solid dose versus incident Ar+ dose. The shaded blocks represent splatter of the quickly frozen target, while the unshaded blocks represent the target that was. The normalized differential sputter yield vs. 6 for indium sputtered from the slowly frozen eutectic target during the first run listed in Table 4 .
Photograph of the ion scattering spectroscopy apparatus inserted between the analyzing magnet and the target. Each point represents the number of detected particles per 10-7 Coulomb of incident 2 keV Ar+ on the target. An earlier sputter cleaning exposed some of the tantalum on which the liquid alloy was supported.
This amplifier is called "high voltage11" in the schematic in Figure 33 to distinguish it from the amplifier used to amplify and shape the channeltron detector pulses.
