(Invited) Synthesis, Characterization, and Application of Tunable Resistance Coatings Prepared by Atomic Layer Deposition

Abstract

We describe the synthesis, characterization, and application of nanocomposite, tunable resistance coatings consisting of conducting, metallic nanoparticles embedded in an amorphous dielectric matrix. These films are comprised of M:Al2O3 with M=Mo or W, and are prepared by atomic layer deposition (ALD) using alternating exposures to trimethyl aluminum and H2O for the Al2O3 ALD and alternating MF6/Si2H6 exposures for the metal ALD. By varying the ratio of ALD cycles for the metal and the Al2O3 components in the film, we can tune precisely the resistance of these coatings over a very broad range from 105-1012 Ohm.cm. These films exhibit ohmic behavior and resist breakdown even at high electric fields of 107 V/m. Moreover, the self-limiting nature of ALD allows us to grow these films inside of porous substrates and on complex 3D surfaces. As a result of these qualities, our nanocomposite films have proved exceptional as resistive coatings in microchannel plate electron multipliers and as charge drain coatings in electron-optical devices.