Abstract: An acoustic wave device includes a support substrate, a piezoelectric layer provided over the support substrate, comb-shaped electrodes disposed on the piezoelectric layer, each of the comb-shaped electrodes including electrode fingers exciting an acoustic wave, a temperature compensation film interposed between the support substrate and the piezoelectric layer and having a temperature coefficient of an elastic constant opposite in sign to that of the piezoelectric layer, a boundary layer interposed between the support substrate and the temperature compensation film, an acoustic velocity of a bulk wave propagating through the boundary layer being higher than an acoustic velocity of a bulk wave propagating through the temperature compensation film and being lower than an acoustic velocity of a bulk wave propagating through the support substrate, and an intermediate layer interposed between the support substrate and the boundary layer and having a Q factor less than a Q factor of the boundary layer.

Abstract: To provide a double-sided pressure-sensitive adhesive sheet having high flexing resistance that does not suffer flexure and exfoliation in a flexing test that is closer to the actual use environment. A double-sided pressure-sensitive adhesive sheet having no substrate, containing a pressure-sensitive adhesive composition containing a (meth)acrylate ester (co)polymer (A), and having a glass transition temperature (Tg) defined by a Tan ? peak temperature of dynamic viscoelasticity in a range of ?50° C. to ?20° C., a storage elastic modulus G? at a frequency of 1 Hz and a temperature 100° C. in a range of 2.0×103 to 3.0×104 Pa, and a thickness of 10 ?m or more and 150 ?m or less.

Abstract: In a semiconductor integrated circuit, a P-type epitaxial layer is provided on the entire surface of a P-type bulk substrate. The resistivity of the P-type bulk substrate is set to 1000 &OHgr;·cm, and the thickness and the resistivity of the P-type epitaxial layer is set to 5 &mgr;m and 10 &OHgr;·cm, respectively. Then, a digital section and an analog section are provided remote from each other on the P-type epitaxial layer, where a digital circuit and an analog circuit are formed on the digital section and analog section, respectively. Further a device isolation region reaching the P-type bulk substrate is formed in a region between the digital section and analog section of the P-type epitaxial layer.