The paper discusses properties of YBaCuO thick films produced by screen printing method and followed sintering of a paste made from pre-annealed powder on Yttrium Stabilized Zirconia (YSZ) and MgO substrates. The prepared films have been studied by X-ray diffraction, scanning electron microscopy (SEM) and resistance vs. temperature measurements.

The composition of CMOS control circuit and Vertical-Double-Diffused-MOS (VDMOS) power device on a single chip by using Silicon-On-Insulator (SOI) structure is formulated. Because all the MOS transistors in the CMOS control circuit are not isolated by the trenches, the interference phenomenon between SOI and the substrate is studied. Latch-up is detected thus, the construction of a mechanism to prevent latch-up is also studied. To evaluate the SOI CMOS characteristics the effects of voltage fluctuation on the substrate is analized. The latch-up mechanism is also analized by transient device simulation. As a result of this study a guideline for the immunity of latch-up is established, the features of the mechanism are as follows. First, the latch-up trigger is the charging current of the condenser composed of the oxide layer in the SOI structure. Second, latch-up is normally caused by positive feedback between the parasitic PNP-transistor and the parasitic NPN-transistor. However, in this case, electron diffusion toward the P-well is dominant after the parasitic PNP-transistor falls into high level injection. This feature is different from the conventional mechanism. The high level injection is caused by carrier accumulation in the N- region. Considering the above, it is necessary to; (1) reduce the charging current of the condenser, (2) reduce the parasitic resistance in the N- region of SOI, and (3) reduce the carrier accumulation in SOI for immunity from latch-up.

The preparation of magnetic semiconductor thick film (MST) by means of spray printing and application to a temperature/gas/essence sensor have been proposed. The MST pattern is composed of ferrite, ruthenium compound, carbon black, binder and solvent. After the mixed mgnetic semiconductor fluid is sprayed on a substrate, the sample is sintered at 750. The MST with thickness of 40 µm is printed on the substrate in various shapes such as a plate, a ring or a rod. The magnetic property of MST depends on temperature, and the electrical property responds to gas and natural/artificial fruit essence. Therefore, the multipore ceramic MST operates as a gas sensor with high sensitivity and high stability.