Multilayer structure for an elastic wave device

Abstract

The invention relates to a multilayer structure configured for an elastic wave device (11), the elastic wave device comprising at least one transducer (19) and operating with an elastic wave having a shear wavelength λ and a frequency between 100 MHz and 50 GHz, the multilayer structure comprising: a piezoelectric layer (3), a dielectric layer (5), and a base substrate (7), the piezoelectric layer (3) being made of Lithium Niobate (LiNbO3), the dielectric layer (5) being made of Silicon Dioxide (SiO2), and the base substrate (7) being a silicon substrate, in particular silicon (Si100) or Si111, characterized in that the piezoelectric layer (3) has an orientation (YXl) / θ with θ between 26° and 64°, in particular between 26° and 41°, more particularly between 36° and 41° according to the definition of the IEEE 1949 std-176 standard, hLNO / λ is greater than 0.30,hLNO being the thickness of the piezoelectric layer (3) and λ the shear wavelength of the elastic wave device (11) and, hSiO2 / λ is greater than 0.25, hSiO2 being the thickness of the dielectric layer (5). The invention also relates to a structure characterized in that the piezoelectric layer (3) has an orientation (YXl) / θ with θ between 26° and 64°, in particular between 26° and 41°, more particularly between 36° and 41° according to the definition of IEEE standard 1949 std-176, hLNO / λ is such that dv / dhlno is less than 1 s⁻¹, preferably dv / dhlno = 0, hLNO being the thickness of the piezoelectric layer (3), λ the shear wavelength of the elastic wave device (11) and v the propagation velocity of the shear wave. Fig. 1,

Claims

9.

10.

11.

12. - detachment of the piezoelectric layer at the level of the weakening zone of the rest of the donor substrate. Manufacturing method according to claim 8, wherein the thickness of the transferred layer is less than or equal to 1 pm, preferably less than or equal to 500 nm. Manufacturing process according to claim 8 or 9, the detachment step is followed by epitaxial growth of a piezoelectric layer on the transferred layer. Surface and / or volume elastic wave device, in particular a filter or resonator, comprising a multilayer structure according to any one of claims 1 to 7. Elastic wave device comprising at least two elastic wave devices according to claim 11 which operate at different wavelengths, in particular elastic shear waves in a wavelength range from 0.6 pm to 2 pm, in particular from 0.8 pm to 1.6 pm, and whose transducers of at least two elastic wave devices are made on the same multilayer structure. FIG. 1 >11 FIG. 2 in HAS B D FIG. 3 [Fig. 5] [Fig. 6] a;p FIG. 4 24.8 h LNO / Àf%J [Fig. 8] a / p FIG. 8 [Fig. 10] [HMHz] [Fig. 11] FIG. 10

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