$YBa_2Cu_3O_{7-x}$ superconducting thin films were deposited on the $LaAlO_3$(100) and MgO(100) single crystal substrates by MOCVD(Metal Organic Chemical Vapor Deposition) method. Microstructures of thin films were controlled by varying deposition temperature and pressure. The films grown at 860℃ of deposition temperature and 5.5torr of deposition pressure showed c-axis orientation, while the films deposited at 830℃ and 4.5torr showed a-axis preferred orientation independent of substrates. The films deposited on the $LaAlO_3$ were grown epitaxially and those on the MgO had high angle grain boundaries.
Bridge-type Josephson junctions were fabricated by photolithography and chemical etching with the same line width of 10μm with the line length of 50μm and 100㎛. In order to observe infrared detection characteristics, measurement system was equiped with infrared LED(Light Emitting Diode). Infrared responsivity showed the maximum value when current was $I_c$. The responsivity of a-axis preferred orientation film was higher than that of c-axis orientation film. The responsivity of 100μm length bridge was higher than that of 50μm length bridge at the same film.
