NEW 6 FACE LITHOGRAPHY TECHNIQUE FOR REALIZATION OF CONTACTS ON MU-M SIZE Y1BA2CU3O7-X SINGLE-CRYSTALS

We have developed a new contact technique for use on very small Y1Ba2Cu3O7-x single crystals (typical dimensions: 100 X 100 X 20-mu-m). A precise contact pattern (resolution almost-equal-to 2-mu-m) is realized on the different faces of the sample. This allows the injection of a current parallel to a single crystallographic axis, without mixing of the anisotropic conduction channels. Contact resistivities are satisfactory: 1 X 10(-5) OMEGA cm2 for the ab contacts, 1 X 10(-6) OMEGA cm2 for the c-axis contacts. To date the technique has been used to directly measure the c-axis resistivity of the Y1Ba2Cu3O7-x, compound, but other applications such as anisotropic thermal conductivity and thermoelectric power are possible.