Effects of artificially structured micrometer holes on the transport behavior of Al-doped ZnO layers

We study the transport properties of artificially structured $n$-type ZnO:Al thin films prepared by rf magnetron sputtering on glass substrates. The samples were patterned with an array of $4×4$ and $8×8μm2$ holes. With decreasing hole size, the resistance of the samples increases. Filling the holes with Au or Al increases and decreases the resistance, respectively. All samples show a negative magnetoresistance, which becomes more pronounced with decreasing hole diameter. The filling of the holes with Au or Al reduces the effects of the artificial structuring on the magnetoresistance.