US 2002/0158549 A1Published application

Surface acoustic wave device

AssigneeSumitomo Electric Industries, Ltd.

InventorsKatsuhiro Itakura, Akihiro Hachigo, Hideaki Nakahata, Satoshi Fujii, Shinichi Shikata

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Abstract

A surface acoustic wave (SAW) device is provided that is suitable for mass production and that has excellent operational performance at the superhigh-frequency range. The SAW device comprises (a) a diamond layer 3; (b) a ZnO layer 4, with a thickness of tz, formed on the diamond layer 3; (c) interdigital transducers (IDTs) 5, which excite and receive a SAW, formed on the ZnO layer 4; and (d) an SiO2 layer 6, with a thickness of ts, formed on the ZnO layer 4 so that the SiO2 layer can cover the IDTs 5. The structure of the SAW device is determined by specific numeric ranges of the parameters kh1 and kh2, which are given in equations kb1=5·2π·(tz/λ) and kh2=5·2π·(ts/λ), where λ signifies the wavelength of the fundamental wave of the second mode of the SAW. The SAW device uses the fifth harmonic of the second mode of the SAW.

Claims5

Dependent claims

A surface acoustic wave (SAW) device, being characterized by the conditions of:

(a) the SAW device comprising:
(a1) a diamond layer;
(a2) a ZnO layer:
(a2a) being formed on the diamond layer;
and
(a2b) having a thickness of tz;
(a3) interdigital transducers (IDTs):
(a3a) being formed on the ZnO layer;
and
(a3b) having the function of exciting and receiving a SAW, and
(a4) an SiO2 layer:
(a4a) being formed on the ZnO layer so that the SiO2 layer can cover the IDTs;
and
(a4b) having a thickness of ts;
(b) providing a two-dimensional orthogonal-coordinate system, in which the axis of abscissa represents kh1 and the axis of ordinate represents kh2 , where kh1 is expressed in the equation kh1=5·2π·(tz/λ) and kh2 is expressed in the equation kh2=5·2π·(ts/λ), λ signifying the wavelength of the fundamental wave of the second mode of the SAW;
(c) In the orthogonal-coordinate system, connecting:
point A given by the coordinates “kh1=4.4 and kh2=7.4”;
point B given by the coordinates “kh1=5.0 and kh2=6.9”;
point C given by the coordinates “kh1=5.2 and kh2=6.2”;
point D given by the coordinates “kh1=5.0 and kh2=5.6”;
point E given by the coordinates “kh1=4.5 and kh2=5.1”;
point F given by the coordinates “kh1=4.0 and kh2=4.6”;
point G given by the coordinates “kh1=3.5 and kh2=4,4”;
point H given by the coordinates “kh1=3.0 and kh2=4.1”;
point I given by the coordinates “kh1=2.8 and kh2=4.0”;
point J given by the coordinates “kh1=2.6 and kh2=3.4”;
point K given by the coordinates “kh1=3.0 and kh2=3.0”;
point L given by the coordinates “kh1=3.5 and kh2=2.9”;
point M given by the coordinates “kh1=3.5 and kh2=2.0”;
point N given by the coordinates “kh1=3.0 and kh2=2.0”;
point O given by the coordinates “kh1=2.5 and kh2=2.0”;
point P given by the coordinates “kh1=2.0 and kh2=2.0”;
point Q given by the coordinates “kh1=1.8 and kh2=2.6”;
point R given by the coordinates “kh1=1.7 and kh2=4.0”;
point S given by the coordinates “kh1=2.0 and kh2=4.5”;
point T given by the coordinates “kh1=2.5 and kh2=5.2”;
point U given by the coordinates “kh1=3.0 and kh2=5.7”;
point V given by the coordinates “kh1=3.5 and kh2=6.1”;
point W given by the coordinates “kh1=4.0 and kh2=6.8”;
and
point A
in this order to provide the range of ABCDEFGHIJKLMNOPQRSTUVWA surrounded by 23 lengths of lines;
(d) structuring the SAW device so that kh1 and kh2 can fall in the range of ABCDEFGHIJKLMNOPQRSTUVWA including the surrounding 23 lengths of lines;
and
(e) using the fifth harmonic of the second mode of the SAW.

42 more elements

A SAW device, being characterized by the conditions of:

(a) the SAW device comprising:
(a1) a diamond layer;
(a2) a ZnO layer:
(a2a) being formed on the diamond layer;
and
(a2b) having a thickness of tz;
(a3) IDTs:
(a3a) being formed on the ZnO layer;
and
(a3b) having the function of exciting and receiving a SAW, and
(a4) an SiO2 layer:
(a4a) being formed on the ZnO layer so that the SiO2 layer can cover the IDTs;
and
(a4b) having a thickness of ts;
(b) providing a two-dimensional orthogonal-coordinate system, in which the axis of abscissa represents kh1 and the axis of ordinate represents kh2, where kh1 is expressed in the equation kh1=5·2π·(tz/λ) and kh2 is expressed in the equation kh=5·2π·(ts/λ), λ signifying the wavelength of the fundamental wave of the second mode of the SAW;
(c) In the orthogonal-coordinate system, connecting:
point A given by the coordinates “kh1=4.4 and kh2=6.9”;
point B given by the coordinates “kh1=5.0 and kh2=6.4”;
point C given by the coordinates “kh1=5.2 and kh2=6.2”;
point D given by the coordinates “kh1=5.0 and kh2=5.6”;
point E given by the coordinates “kh1=4.6 and kh2=5.2”;
point F given by the coordinates “kh1=4.4 and kh2=5.0”;
point G given by the coordinates “kh1=4.0 and kh2=4.6”;
point H given by the coordinates “kh1=3.5 and kh2=4.4”;
point I given by the coordinates “kh1=3.0 and kh2=4.1”;
point J given by the coordinates “kh1=2.8 and kh2=4.0”;
point K given by the coordinates “kh1=2.6 and kh2=3.4”;
point L given by the coordinates “kh1=2.8 and kh2=3.0”;
point M given by the coordinates “kh1=3.2 and kh2=2.4”;
point N given by the coordinates “kh1=2.7 and kh2=2.4”;
point O given by the coordinates “kh1=2.2 and kh2=3.0”;
point P given by the coordinates “kh1=2.2 and kh2=3.5”;
point Q given by the coordinates “kh1=2.5 and kh2=4.7”;
point R given by the coordinates “kh1=3.0 and kh2=5.2”;
point S given by the coordinates “kh1=3.5 and kh2=5.7”;
point T given by the coordinates “kh1=4.0 and kh2=6.3”;
and
point A
in this order to provide the range of ABCDEFGHIJKLMNOPQRSTA surrounded by 20 lengths of lines;
(d) structuring the SAW device so that kh1 and kh2 can fall in the range of ABCDEFGHIJKLMNOPQRSTA including the surrounding 20 lengths of lines;
and
(e) using the fifth harmonic of the second mode of the SAW.

39 more elements

Dependencies are inferred from the claim text.