Optimized sputered YBa_2Cu_3O_7 films on CeO_2 buffered sapphire substrates are patterned into square lattices of submicrometer holes (antidots) with diameters of 250-450 nm and lattice parameters of d=0.5-5 #mu#m without deterioration of the superconducting properties. In the mixed state, matching effects between Abrikosov vortex lattice and artificial antidot array are observed for the first time. Resistive measurements show an increase of the critical current I_c for films with antidots and cusps in I_c-versus-B (magnetic induction) at integers and specific rationales of the matching field B_m=(#phi#_0/d~2). Additionally, measurements of the noise pectra of rf-SQUIDs demonstrate the presents of matching effects even for magnetic fields BB_m. Vortices within the grain boundary of the washer of bicrystal rf-SQUIDs can either be trapped in case of commensurability (leading to noise reduction) or exposed to a kind of double potential in case of incommensurability (increased noise). The experimental results are discussed in context of existing theories. The formation of multi-quanta vortices confined by the holes is considered.
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