Boundary acoustic wave device
A boundary acoustic wave device includes a quartz substrate, an IDT located on the substrate, and a dielectric arranged so as to cover the IDT. A boundary acoustic wave propagates across a boundary between the quartz substrate and the dielectric. The thickness of the IDT is determined so that the velocity of the SH boundary acoustic wave is below those of a slow transverse wave propagating across the quartz substrate and a slow transverse wave propagating across the dielectric. The Eulerian angles of the quartz substrate lie within hatched regions in FIG. 13.
1. A boundary acoustic wave device comprising:
a quartz substrate;
an IDT located on the quartz substrate; and
a dielectric arranged on the quartz substrate so as to cover the IDT; wherein
a boundary acoustic wave propagates across a boundary between the quartz substrate and the dielectric;
a thickness of the IDT is determined so that the velocity of the boundary acoustic wave is below those of a slow transverse wave propagating across the quartz substrate and a slow transverse wave propagating across the dielectric; and
θ and ψ of Euler angles (0°, θ, ψ) of the quartz substrate are in any one of regions surrounded by points A01 to A16, B01 to B16, C01 to C16, D01 to D13, E01 to E17, F01 to F11, G01 to G23, and H01 to H14 in the Tables 1 to 8:
TABLE 1
θ[°]
ψ[°]
A01
100
146
A02
110
144
A03
120
144
A04
130
145
A05
136
147
A06
140
151
A07
140
156
A08
135
163
A09
130
166
A10
125
168
A11
120
168
A12
112
168
A13
110
166
A14
98
155
A15
97
150
A16
100
146
TABLE 2
θ[°]
ψ[°]
B01
83
100
B02
86
95
B03
92
93
B04
100
92
B05
150
86
B06
180
81
B07
180
110
B08
151
126
B09
140
128
B10
130
129
B11
120
129
B12
105
127
B13
95
122
B14
85
110
B15
83
105
B16
83
100
TABLE 3
θ[°]
ψ[°]
C01
104
60
C02
109
55
C03
118
52
C04
131
52
C05
146
54
C06
152
56
C07
161
60
C08
165
65
C09
160
70
C10
150
72
C11
140
73
C12
130
73
C13
120
72
C14
114
71
C15
105
66
C16
104
60
TABLE 4
θ[°]
ψ[°]
D01
95
31
D02
100
36
D03
180
50
D04
180
19
D05
150
12
D06
140
11
D07
130
10
D08
120
10
D09
111
12
D10
106
14
D11
102
18
D12
98
23
D13
95
31
TABLE 5
θ[°]
ψ[°]
E01
0
170
E02
15
175
E03
20
176
E04
75
177
E05
80
176
E06
85
175
E07
88
173
E08
87
168
E09
80
161
E10
70
154
E11
60
149
E12
50
144
E13
35
142
E14
18
140
E15
10
140
E16
0
141
E17
0
170
TABLE 6
θ[°]
ψ[°]
F01
23
121
F02
27
125
F03
45
128
F04
50
128
F05
55
125
F06
55
122
F07
50
116
F08
45
113
F09
35
113
F10
30
115
F11
23
121
TABLE 7
θ[°]
ψ[°]
G01
0
111
G02
10
105
G03
20
100
G04
30
95
G05
40
93
G06
55
92
G07
65
90
G08
70
88
G09
71
83
G10
70
72
G11
65
55
G12
55
51
G13
33
50
G14
25
40
G15
0
21
G16
0
51
G17
17
54
G18
20
56
G19
23
60
G20
18
70
G21
10
77
G22
0
82
G23
0
111
TABLE 8
θ[°]
ψ[°]
H01
22
11
H02
23
17
H03
33
25
H04
45
30
H05
52
31
H06
60
30
H07
69
26
H08
73
21
H09
72
15
H10
66
11
H11
46
6
H12
33
6
H13
26
8
H14
22
11.
2. The boundary acoustic wave device according to claim 1 , wherein the thickness and width of each electrode finger of the IDT are determined so that the velocity of the boundary acoustic wave is below those of the slow transverse wave propagating across the quartz and the slow transverse wave propagating across the dielectric.
3. The boundary acoustic wave device according to claim 1 , wherein the IDT includes IDT electrodes including at least one metal selected from the group consisting of nickel, molybdenum, iron, copper, tungsten, silver, tantalum, gold, and platinum.
4. The boundary acoustic wave device according to claim 1 , wherein the dielectric is formed of polycrystalline silicon or amorphous silicon.
5. The boundary acoustic wave device according to claim 1 , wherein the dielectric is formed of a material selected from the group consisting of aluminum nitride, glass, lithium tetraborate, lithium niobate, lithium tantalate, sapphire, silicon nitride, and alumina.
6. A boundary acoustic wave device comprising:
a quartz substrate;
an IDT located on the quartz substrate; and
a dielectric arranged on the quartz substrate so as to cover the IDT; wherein
a boundary acoustic wave propagates across a boundary between the quartz substrate and the dielectric;
a thickness of the IDT is determined so that the velocity of the boundary acoustic wave is below those of a slow transverse wave propagating across the quartz substrate and a slow transverse wave propagating across the dielectric; and
θ and ψ of Euler angles (0°, θ, ψ) of the quartz substrate are in any one of regions surrounded by points I01 to I24 and J01 to J24 in Tables 1 and 2:
TABLE 1
θ[°]
ψ[°]
I01
0
180
I02
28
180
I03
31
170
I04
43
158
I05
56
150
I06
78
140
I07
78
134
I08
70
130
I09
60
124
I10
51
116
I11
43
106
I12
40
99
I13
37
91
I14
39
80
I15
50
65
I16
63
54
I17
78
44
I18
78
41
I19
60
32
I20
46
24
I21
33
16
I22
26
0
I23
0
0
I24
0
180
TABLE 2
θ[°]
ψ[°]
J01
180
180
J02
120
180
J03
120
170
J04
124
165
J05
122
145
J06
125
140
J07
135
134
J08
142
128
J09
149
115
J10
147
103
J11
142
93
J12
141
88
J13
143
84
J14
150
70
J15
150
65
J16
145
55
J17
140
50
J18
127
41
J19
121
35
J20
123
14
J21
119
10
J22
120
0
J23
180
0
J24
180
180.
7. The boundary acoustic wave device according to claim 6 , wherein the thickness and width of each electrode finger of the IDT are determined so that the velocity of the boundary acoustic wave is below those of the slow transverse wave propagating across the quartz and the slow transverse wave propagating across the dielectric.
8. The boundary acoustic wave device according to claim 6 , wherein the IDT includes IDT electrodes including at least one metal selected from the group consisting of nickel, molybdenum, iron, copper, tungsten, silver, tantalum, gold, and platinum.
9. The boundary acoustic wave device according to claim 6 , wherein the dielectric is formed of polycrystalline silicon or amorphous silicon.
10. The boundary acoustic wave device according to claim 6 , wherein the dielectric is formed of a material selected from the group consisting of aluminum nitride, glass, lithium tetraborate, lithium niobate, lithium tantalate, sapphire, silicon nitride, and alumina.
11. A boundary acoustic wave device comprising:
a quartz substrate;
an IDT located on the quartz substrate; and
a dielectric arranged on the quartz substrate so as to cover the IDT; wherein
a boundary acoustic wave propagates across a boundary between the quartz substrate and the dielectric;
a thickness of the IDT is determined so that the velocity of the boundary acoustic wave is below those of a slow transverse wave propagating across the quartz substrate and a slow transverse wave propagating across the dielectric; and
θ and ψ of Euler angles (0°, θ, ψ) of the quartz substrate are in any one of regions surrounded by points K01 to K14, L01 to L18, M01 to M19, N01 to N15, O01 to O14, P01 to P10, Q01 to Q10, and R01 to R17 in Tables 1 to 8:
TABLE 1
θ[°]
ψ[°]
K01
99
150
K02
99
155
K03
103
161
K04
111
167
K05
124
169
K06
142
165
K07
158
157
K08
161
150
K09
161
146
K10
152
142
K11
131
142
K12
118
144
K13
106
146
K14
99
150
TABLE 2
θ[°]
ψ[°]
L01
100
111
L02
100
115
L03
103
122
L04
110
126
L05
125
129
L06
140
127
L07
151
124
L08
160
120
L09
166
115
L10
169
111
L11
168
105
L12
162
103
L13
151
100
L14
130
100
L15
123
101
L16
112
103
L17
105
106
L18
100
111
TABLE 3
θ[°]
ψ[°]
M01
100
66
M02
100
71
M03
105
75
M04
113
78
M05
129
81
M06
139
82
M07
146
82
M08
155
81
M09
160
79
M10
168
76
M11
169
70
M12
165
65
M13
158
60
M14
145
55
M15
133
53
M16
117
53
M17
109
55
M18
105
58
M19
100
66
TABLE 4
θ[°]
ψ[°]
N01
99
31
N02
101
33
N03
108
36
N04
147
40
N05
155
38
N06
161
35
N07
161
30
N08
157
24
N09
145
17
N10
129
13
N11
118
13
N12
110
15
N13
103
20
N14
99
26
N15
99
31
TABLE 5
θ[°]
ψ[°]
O01
10
165
O02
17
172
O03
32
175
O04
48
175
O05
62
173
O06
76
166
O07
76
162
O08
70
155
O09
60
151
O10
47
147
O11
35
147
O12
20
151
O13
12
157
O14
10
165
TABLE 6
θ[°]
ψ[°]
P01
28
121
P02
30
124
P03
35
126
P04
51
126
P05
56
121
P06
56
111
P07
48
104
P08
36
104
P09
28
110
P10
28
121
TABLE 7
θ[°]
ψ[°]
Q01
29
72
Q02
36
77
Q03
48
77
Q04
56
70
Q05
56
60
Q06
51
55
Q07
40
55
Q08
30
58
Q09
28
62
Q10
29
72
TABLE 8
θ[°]
ψ[°]
R01
10
15
R02
13
25
R03
16
27
R04
20
30
ROS
26
32
R06
40
34
R07
48
34
R08
55
32
R09
70
25
R10
73
24
R11
76
19
R12
76
14
R13
65
9
R14
52
7
R15
30
7
R16
17
9
R17
10
15.
12. The boundary acoustic wave device according to claim 11 , wherein the thickness and width of each electrode finger of the IDT are determined so that the velocity of the boundary acoustic wave is below those of the slow transverse wave propagating across the quartz and the slow transverse wave propagating across the dielectric.
13. The boundary acoustic wave device according to claim 11 , wherein the IDT includes IDT electrodes including at least one metal selected from the group consisting of nickel, molybdenum, iron, copper, tungsten, silver, tantalum, gold, and platinum.
14. The boundary acoustic wave device according to claim 11 , wherein the dielectric is formed of polycrystalline silicon or amorphous silicon.
15. The boundary acoustic wave device according to claim 11 , wherein the dielectric is formed of a material selected from the group consisting of aluminum nitride, glass, lithium tetraborate, lithium niobate, lithium tantalate, sapphire, silicon nitride, and alumina.