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We have produced Bi2Sr2CaCu208+δ/ Bi2Sr2YCu208+δ/Bi2Sr2CaCu208+δ herostructures using a high pressure dc sputtering technique. The films have been deposited in situ at high oxygen pressure on (001) SrTi03 substrates. X-ray diffraction and high resolution transmission electron microscopy (WRTEM) showed highly c-axis oriented trilayers. TEM analysis showed sharp interfaces between the superconducting films and the barrier, without intermediate amorphous regions. The Bi2Sr2CaCu208+δ layers had superconducting transition temperatures of 87 K, with ΔTc⩽1 K, while the barrier layers showed a semiconductor-like behavior explained in terms of variable range hopping process. At low temperatures the conductance versus voltage characteristics exhibit peaks indicative of gap-like structures at about ±30 mV, finite conductances at zero bias and flat backgrounds for energies higher than 30 mV.