Surface acoustic wave device and method of manufacturing the same

A surface acoustic wave device comprising:

• a hard layer comprising diamond;
• a piezoelectric layer disposed on said hard layer;
• a layer comprising silicon dioxide disposed on said piezoelectric layer;
• an interdigital transducer;
• and
• a grounding electrode comprising a conductive oxide, disposed at a position corresponding to said interdigital transducer;
• said interdigital transducer and said grounding electrode being disposed with said piezoelectric layer therebetween, and either said interdigital transducer or said grounding electrode being disposed on said hard layer.

A surface acoustic wave device comprising:

• a hard layer comprising diamond;
• a piezoelectric layer disposed on said hard layer and comprising one or more materials selected from the group consisting of ZnO, AlN, PB(Zr, Ti)O.sub.3, (Pb, La)(Zr, Ti)O.sub.3, LiTaO.sub.3, LiNbO.sub.3, SiO.sub.2, Ta.sub.2 O.sub.5, Nb.sub.2 O.sub.5, BeO, Li.sub.2 B.sub.4 O.sub.7, KNbO.sub.3, ZnS, ZnSe and CdS;
• an interdigital transducer;
• and
• a grounding electrode having a resistivity less than or equal to 10.sup.-2 .OMEGA.cm, comprising a conductive oxide formed by doping an impurity into material constituting said piezoelectric layer, and being disposed at a position corresponding to said interdigital transducer;
• said interdigital transducer and said grounding electrode being disposed with said piezoelectric layer therebetween, and either said interdigital transducer or said grounding electrode being disposed on said hard layer.

A surface acoustic wave device comprising:

• a hard layer comprising a diamond-like carbon film;
• a piezoelectric layer disposed on said hard layer;
• an interdigital transducer;
• a grounding electrode comprising a conductive oxide, disposed at a position corresponding to said interdigital transducer;
• and
• a layer comprising silicon dioxide;
• said interdigital transducer and said grounding electrode being disposed with said piezoelectric layer therebetween, and either said interdigital transducer or said grounding electrode being disposed on said hard layer.

A surface acoustic wave device comprising:

• a hard layer comprising a diamond-like carbon film;
• a piezoelectric layer disposed on said hard layer and comprising one or more materials selected from the group consisting of ZnO, AlN, PB(Zr, Ti)O.sub.3, (Pb, La)(Zr, Ti)O.sub.3, LiTaO.sub.3, LiNbO.sub.3, SiO.sub.2, Ta.sub.2 O.sub.5, Nb.sub.2 O.sub.5, BeO, Li.sub.2 B.sub.4 O.sub.7, KNbO.sub.3, ZnS, ZnSe and CdS;
• an interdigital transducer;
• and
• a grounding electrode having a resistivity less than or equal to 10.sup.-2 .OMEGA.cm, comprising a conductive oxide formed by doping an impurity into material constituting said piezoelectric layer, and being disposed at a position corresponding to said interdigital transducer;
• said interdigital transducer and said grounding electrode being disposed with said piezoelectric layer therebetween, and either said interdigital transducer or said grounding electrode being disposed on said hard layer.