33 research outputs found
Electronic cooling of a submicron-sized metallic beam
We demonstrate electronic cooling of a suspended AuPd island using
superconductor-insulator-normal metal tunnel junctions. This was achieved by
developing a simple fabrication method for reliably releasing narrow submicron
sized metal beams. The process is based on reactive ion etching and uses a
conducting substrate to avoid charge-up damage and is compatible with e.g.
conventional e-beam lithography, shadow-angle metal deposition and oxide tunnel
junctions. The devices function well and exhibit clear cooling; up to factor of
two at sub-kelvin temperatures.Comment: 4 pages, 3 figure
Application of ultra-thin aluminum oxide etch mask made by atomic layer deposition technique
Peer reviewe
Plasma etch characteristics of aluminum nitride mask layers grown by low-temperature plasma enhanced atomic layer deposition in SF6 based plasmas
The plasma etch characteristics of aluminum nitride (AlN) deposited by low-temperature, 200 C,
plasma enhanced atomic layer deposition (PEALD) was investigated for reactive ion etch (RIE) and
inductively coupled plasma-reactive ion etch (ICP-RIE) systems using various mixtures of SF6 and O2
under different etch conditions. During RIE, the film exhibits good mask properties with etch rates
below 10r nm/min. For ICP-RIE processes, the film exhibits exceptionally low etch rates in the
subnanometer region with lower platen power. The AlN filmâs removal occurred through physical
mechanisms; consequently, rf power and chamber pressure were the most significant parameters in
PEALD AlN film removal because the film was inert to the SFĂŸ
x and OĂŸ chemistries. The etch
experiments showed the film to be a resilient masking material. This makes it an attractive candidate for
use as an etch mask in demanding SF6 based plasma etch applications, such as through-wafer etching,
or when oxide films are not suitable.peerReviewe
Reversible switching between superhydrophobic states on a hierarchically structured surface
Nature offers exciting examples for functional wetting properties based on superhydrophobicity, such as the self-cleaning surfaces on plant leaves and trapped air on immersed insect surfaces allowing underwater breathing. They inspire biomimetic approaches in science and technology. Superhydrophobicity relies on the Cassie wetting state where air is trapped within the surface topography. Pressure can trigger an irreversible transition from the Cassie state to the Wenzel state with no trapped airâthis transition is usually detrimental for nonwetting functionality and is to be avoided. Here we present a new type of reversible, localized and instantaneous transition between two Cassie wetting states, enabled by two-level (dual-scale) topography of a superhydrophobic surface, that allows writing, erasing, rewriting and storing of optically displayed information in plastrons related to different length scales