In a development that could lead to more advanced computer chips and light-emitting diodes, researchers from the University of California Los Angeles have created a new method for building semiconductor devices that eliminates efficiency-sapping atomic-scale defects.
Standard methods used to create semiconductor devices produce tiny defects that can trap electrons passing in between the semiconductor and its neighboring metal electrodes, which makes these devices less effective than they might be in theory.
The electrodes in semiconductor-based devices allow electrons to go to and from the semiconductor, carrying computing data or energy with them.
Typically, metal electrodes in semiconductor devices are created using a method known as physical vapor deposition.
In this technique, metallic materials are vaporized into atoms or atomic groupings that then settle onto the semiconductor, which can be silicon or a similar material.
The metal atoms adhere to the semiconductor through robust chemical bonds, ultimately developing a thin film of electrodes on top of the semiconductor.
One problem with that method is the metal atoms are generally different sizes or shapes from the atoms in the semiconductor materials that they’re connecting to.
Consequently, the layers cannot form ideal one-to-one atomic contacts, which is why little gaps or defects appear. Those gaps can snare electrons passing across them, and the electrons need more energy to get through those places.
Study author Yu Huang, professor of materials science and engineering at UCLA, compared the problem of trying to combine different atoms to trying to fit Lego blocks with similar plastic blocks from a competitor.
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