Charge State Dependent Energy Deposition by Ion Impact

Abstract

We report on a measurement of craters in thin dielectric films formed by Xe(Q+) (26 ≤ Q ≤ 44) projectiles. Tunnel junction devices with ion-irradiated barriers were used to amplify the effect of charge-dependent cratering through the exponential dependence of tunneling conductance on barrier thickness. Electrical conductance of a crater σ(c)(Q) increased by 4 orders of magnitude (7.9 × 10(-4) μS to 6.1 μS) as Q increased, corresponding to crater depths ranging from 2 to 11 Å. By employing a heated spike model, we determine that the energy required to produce the craters spans from 8 to 25 keV over the investigated charge states. Considering energy from preequilibrium nuclear and electronic stopping as well as neutralization, we find that at least (27 ± 2)% of available projectile neutralization energy is deposited into the thin film during impact.

Reduced resistance drift in tunnel junctions using confined tunnel barriers

“…23. Throughout the entirety of the processing, the wafer is held in a stainless-steel cassette and in electrical contact with the chamber ground.…”

“…As a note, the devices presented here are representative samples from a very large number of devices made using the same processes spanning over a decade. 23,30,31 …”

Highly charged ion induced nanostructures at surfaces by strong electronic excitations

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Energy deposition by heavy ions: Additivity of kinetic and potential energy contributions in hillock formation on CaF2

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