What we claim is:
1. A photovoltaic device comprising
a one conductive type crystalline semiconductor,
an intrinsic amorphous semiconductor thin film without dopant of a conductive impurity or a substantially intrinsic amorphous semiconductor thin film formed thereon,
a one conductive type or an other conductive type amorphous semiconductor thin film formed on said intrinsic amorphous semiconductor thin film without dopant of a conductive impurity or a substantially intrinsic amorphous semiconductor thin film, wherein
a one conductive type or an other conductive type impurity is provided at an interface formed from said crystalline semiconductor and said intrinsic amorphous semiconductor thin film without dopant of a conductive impurity or said substantially intrinsic amorphous semiconductor thin film.
2. The photovoltaic device according to claim 1, wherein
said crystalline semiconductor and said amorphous semiconductor thin film are crystalline silicon and an amorphous silicon thin film respectively, and
said one conductive type impurity is an atomic element in 5B group of the periodic table whose atomy surface density at the interface is in ranges between 11011 cm2 and 51014 cm2.
3. The photovoltaic device according to claim 1, wherein
said crystalline semiconductor and said amorphous semiconductor thin film are crystalline silicon and an amorphous silicon thin film respectively, and
said other conductive type impurity is an atomic element in 3B group of the periodic table whose atomy surface density at the interface is in ranges between 11011 cm2 and 51013 cm2.
4. The photovoltaic device according to claim 1 wherein
said crystalline semiconductor and said amorphous semiconductor thin film are crystalline silicon and an amorphous silicon thin film respectively,
said one conductive type impurity is an atomic element in 5B group of the periodic table whose atomy surface density at the interface is in ranges between 11011 cm2 and 51014 cm2, and
said other conductive type impurity is an atomic element in 3B group of the periodic table whose atomy surface density at the interface is in ranges between 11011 cm2 and 51013 cm2.
5. The photovoltaic device according to claim 1, wherein
said crystalline semiconductor and said amorphous semiconductor thin film are crystalline silicon and an amorphous silicon thin film respectively, and
said one conductive type impurity is an atomic element in 3B group of the periodic table whose atomy surface density at the interface is in ranges between 11011 cm2 and 51013 cm2.
6. The photovoltaic device according to claim 1, wherein
said crystalline semiconductor and said amorphous semiconductor thin film are crystalline silicon and an amorphous silicon thin film respectively, and
said other conductive type impurity is an atomic element in 5B group of the periodic table whose atomy surface density at the interface is in ranges between 11011 cm2 and 51014 cm2.
7. The photovoltaic device according to claim 1 wherein
said crystalline semiconductor and said amorphous semiconductor thin film are crystalline silicon and an amorphous silicon thin film respectively,
said one conductive type impurity is an atomic element in 3B group of the periodic table whose atomy surface density at the interface is in ranges between 11011 cm2 and 51013 cm2, and
said other conductive type impurity is an atomic element in 5B group of the periodic table whose atomy surface density at the interface is in ranges between 11011 cm2 and 51014 cm2.
8. A manufacturing method comprising
a process for cleaning a front surface of a one conductive type or an other conductive type crystalline semiconductor substrate by plasma discharge introducing a hydrogen gas and a gas containing a one conductive type or an other conductive type impurity,
a process for forming an intrinsic amorphous semiconductor thin film without dopant of a conductive impurity or a substantially intrinsic amorphous semiconductor thin film on said front surface of the crystalline semiconductor substrate, and
a process for forming an amorphous semiconductor thin film thereon, said amorphous semiconductor thin film made to be one conductive type or other conductive type by doping a one conductive type or an other conductive type impurity.
9. A manufacturing method of a photovoltaic device comprising
a process for forming a first amorphous semiconductor thin film by gas phase reaction introducing a gas containing a material to constitute an amorphous semiconductor thin film on a front surface of a crystalline semiconductor substrate and a gas containing a one conductive type or an other conductive type impurity,
a process for forming a substantially intrinsic second amorphous semiconductor thin film by gas phase reaction on said first amorphous semiconductor thin film, and
a process for forming an amorphous semiconductor thin film on said second amorphous semiconductor thin film, said amorphous semiconductor thin film made to be one conductive type or other conductive type by doping a one conductive type or an other conductive type impurity.
10. A manufacturing method comprising
a process for exposing a one conductive type or an other conductive type crystalline semiconductor substrate in a heated condition to a one conductive type or an other conductive type impurity of low density as well as hydrogen gas,
a process for forming an intrinsic amorphous semiconductor thin film without dopant of a conductive impurity or a substantially intrinsic amorphous semiconductor thin film on a front surface of said crystalline semiconductor substrate, and
a process for forming an amorphous semiconductor thin film thereon, said amorphous semiconductor thin film made to be one conductive type or other conductive type by doping a one conductive type or an other conductive type impurity.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A surface acoustic wave device comprising:
a single crystal LiNbO3 piezoelectric substrate for providing a propagation of a leaky acoustic wave, the substrate having an electromechanical coupling factor exceeding 5%, and an orientation defined by Euler angles (0\xb13\xb0,\u03b8,0\xb13\xb0), with angle \u03b8=90\u2212\u03b8\u2032, where \u03b8\u2032 is a YX rotation angle of the substrate that ranges from about \u221240\xb0 to about \u221220\xb0;
an electrode pattern formed from electrodes provided on a surface of the piezoelectric substrate, the electrode pattern forming at least one resonator and the electrodes primarily formed from copper, wherein a thickness of the copper electrode pattern ranges from 0.15p to 0.25p, and wherein \u201cp\u201d being a period of the electrodes within the electrode pattern; and
a dielectric overcoat comprising a SiOx, the dielectric overcoat having a positive TCF, the dielectric overcoat disposed between and over the electrodes of the electrode pattern, wherein a density of the electrodes substantially exceeds a density of the dielectric overcoat, the dielectric overcoat having a thickness in the range of hoxp=0.30*(hCu\u22120.15)(0.20p\u22120.15)+\u22120.05, wherein \u201chox\u201d is a thickness of the overcoat as measured above a top surface of the electrodes, and \u201chCu\u201d is a thickness of the electrodes within the electrode pattern.
2. A surface acoustic wave device according to claim 1, further comprising at least two resonators, wherein the dielectric overcoat layer comprises silicon oxide, the first resonator having a first silicon oxide overcoat layer of thickness hox1 and electrode period p1, the second resonator having a second silicon oxide overcoat layer of thickness hox2 and an electrode period p2, the first and second overcoat layers defined by hox1p1 and hox2p2, respectively.
3. A surface acoustic wave device according to claim 1, further comprising at least two resonators, wherein the first resonator has a silicon oxide layer of thickness hox1 and electrode period p1 and wherein the second resonator has a silicon oxide layer of thickness hox2 and an electrode period p2, the two resonators having nominal periods and overcoat thicknesses satisfying the relationship (hox1p1\u2212hox2p2)(hCup1\u2212hCup2)>5.
4. A surface acoustic wave device according to claim 1, wherein the thickness of the dielectric overcoat above the at least one resonator nominally increases as a period of the at least one resonator decreases.
5. A surface acoustic wave device according to claim 1, wherein the thickness of one dielectric overcoat is specified to be inversely related to a period of the at least one resonator.
6. A surface acoustic wave device according to claim 5, further comprising an etch stop layer, wherein the etch stop layer comprises at least one of SiN and AlN.
7. A surface acoustic wave device according to claim 1, wherein a surface of the dielectric overcoat is planar.
8. A surface acoustic wave device comprising:
a single crystal piezoelectric substrate for providing a propagation of a leaky acoustic wave, the substrate having an electromechanical coupling factor exceeding 5%; and
an electrode pattern formed from electrodes provided on a surface of the piezoelectric substrate forming at least two resonators, wherein a first resonator has a silicon oxide layer of thickness hox1 and electrode period p1 and a second resonator has a silicon oxide layer of thickness hox2 and an electrode period p2, wherein the dielectric overcoat thicknesses of the at least two resonators are specified to be inversely related to the period of the resonator electrode.
9. A surface acoustic wave device according to claim 8, wherein the thicknesses of the dielectric overcoats above the at least two resonators nominally increases as a period of the at least two resonators decreases.
10. A surface acoustic wave device according to claim 8, wherein the electrode is composed primarily of Copper.
11. A surface acoustic wave device according to claim 10, wherein the two resonators have electrode periods and overcoat thicknesses satisfying the relationship (hox1p1\u2212hox2p2)(hCup1\u2212hCup2)>5, hCu representing a thickness of the Copper electrodes.
12. A surface acoustic wave device according to claim 8, wherein the thickness of electrodes is in a range of about 10% to about 30% of an electrode period; and the piezoelectric substrate comprises a Lithium Niobate substrate having an orientation defined by Euler angles (0\xb13\xb0,\u03b8,0\xb13\xb0), with angle \u03b8=90\xb0\u2212\u03b8\u2032 and YX rotation angle \u03b8\u2032.
13. A surface acoustic wave device according to claim 12, wherein \u03b8\u2032 ranges from about \u221240\xb0 to about \u221220\xb0.
14. A surface acoustic wave device comprising:
a single crystal piezoelectric substrate having a surface for providing propagation of acoustic waves;
first and second resonators formed on the surface of the substrate;
first and second electrode patterns including a plurality of electrodes forming the first and second resonators, respectively;
a first dielectric overcoat formed over the first resonator and a second dielectric overcoat formed over the second resonator,
wherein the first resonator includes the first dielectric overcoat having a thickness of hox1 and an electrode period p1,
wherein the second resonator includes the second dielectric overcoat having a thickness hox2 and an electrode period p2, and
wherein the dielectric overcoat thickness for each of the first and second resonators is inversely related to the electrode period of the resonator, thus reducing the electrode period results in an increasing of the dielectric overcoat for maintaining performance of the device, including suppressing a coupling factor for spurious modes for each resonator.
15. A surface acoustic wave device according to claim 14, wherein the dielectric overcoat comprises SiOx.
16. A surface acoustic wave device according to claim 14, wherein the substrate comprises an electromechanical coupling factor exceeding 5%.
17. A surface acoustic wave device according to claim 14, wherein each of the plurality of electrodes is composed substantially of Copper.
18. A surface acoustic wave device according to claim 17, wherein the two resonators have electrode periods and overcoat thicknesses satisfying the relationship (hox1p1\u2212hox2p2)(hCup1\u2212hCup2)>5, hCu representing a thickness of the Copper electrodes.
19. A surface acoustic wave device according to claim 14, wherein
the thickness of electrodes is in a range of about 10% to about 30% of an the electrode period; and
the piezoelectric substrate comprises a Lithium Niobate substrate having an orientation defined by Euler angles (0\xb13\xb0,\u03b8,0\xb13\xb0), with angle \u03b8=90\xb0\u2212\u03b8\u2032 and YX rotation angle \u03b8\u2032, where \u03b8\u2032 ranges from about 40\xb0 to about \u221220\xb0.