Silicon microcantilever beams are fractured and characterized. The specially designed beams, etched into two wafers, are loaded to fracture in bending using a unique measurement system. A finite element model of the beams is created, and ABAQUS is used to calculate the displacements and stresses produced by an applied load force. A special testing scheme is devised to obtain certain model parameters: E͗110͘, the Young's modulus along the length of the beam and L force , the position of the applied force. With these parameters defined, the model is well correlated with that of the experimental data. The fracture stress ͑strength͒ of the beam is obtained from the stress produced in the model at the fracture location by a load equivalent to the experimental fracture force. This fracture stress can be used as a design parameter for silicon micromechanical structures. Numerous beams are fractured from both the front and back sides of the wafer, and statistical fracture strength results are compiled for each of these cases. The fracture strength of the front side, 3.3 GPa ͑average͒, is significantly greater than that of the backside, 1.0 GPa ͑average͒. This dissimilarity is attributed to the differences in the surface roughness of these sides.

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Superconducting Ba1−xKxBiO3 (BKBO) thin films and heteroepitaxial multilayers were deposited by in situ off-axis sputtering on various substrate at 400 °C. A typical superconducting BKBO thin film on the SrTiO3 and MgO substrates had a very sharp zero resistance transition at a temperature of 22–24 K as measured by transport four point and mutual inductance probes. The normal state resistivity exhibited metallic to semiconductive characteristics depending on film composition with the lowest room temperature resistivity of about 0.25 mΩ cm. The film orientation was highly epitaxial to both SrTiO3 and MgO substrates. Normal metal-insulator-superconductor (NIS) type tunnel functions with native insulator layer and deposited MgO layer were reproducibly fabricated. The superconducting energy gap of about 3.6 meV was obtained from those NIS junctions. Heteroepitaxial superconductor- insulator-superconductor (SIS) trilayer junctions were also fabricated using MgO insulator layers. For a 5 nm thick insulator layer, quasiparticle SIS tunnel junctions with nonhysteric I-V characteristics were obtained. By reducing MgO insulator layer thickness down to 3 nm, SIS tunnel junctions with Josephson supercurrent were obtained with hysteric I-V characteristics.