MEMS DEVICE AND METHOD FOR PRODUCING AN MEMS DEVICE OPERATING WITH ACOUSTIC WAVES

1 . A method for producing an MEMS device ( 1 ) operating with acoustic waves, comprising the following steps:

producing an MEMS component ( 2 ) operating with acoustic waves on a substrate ( 3 ),

encapsulating the component ( 2 ) with a housing layer ( 10 ), wherein the housing layer ( 10 ) is transmissive to electromagnetic radiation ( 14 ) in a wavelength range,

trimming the component ( 2 ) by irradiating the component ( 2 ) with electromagnetic radiation ( 14 ) having a wavelength lying in the wavelength range in which the housing layer ( 10 ) is transmissive to the electromagnetic radiation ( 14 ).

2 . The method according to claim 1 ,

furthermore comprising the following step:

measuring at least one acoustic property of the component ( 2 ) after encapsulating the component ( 2 ), wherein the component ( 2 ), depending on the measured value of the acoustic property, is subsequently irradiated with electromagnetic radiation ( 14 ) in such a way that the acoustic property of the component ( 2 ) is adapted to a desired value specified for the device ( 1 ).

3 . The method according to either of the preceding claims,

wherein the MEMS component ( 2 ) has a resonator having a resonance region ( 15 ), which determines the acoustic properties of the resonator, and a passive region ( 16 , 17 ), which does not directly determine the acoustic properties, wherein the resonance region ( 15 ) of the resonator is irradiated with electromagnetic radiation ( 14 ) if the resonant frequency of the resonator is lower than a desired value specified for the device ( 1 ).

4 . The method according to claim 3 ,

wherein material in the resonance region ( 15 ) is removed as a result of the irradiation with electromagnetic radiation ( 14 ) and deposits uniformly on the entire surface of the component ( 2 ), such that the thickness of the resonator is reduced in the resonance region.

5 . The method according to any of the preceding claims,

wherein the MEMS component ( 2 ) has a resonator having a resonance region ( 15 ), which determines the acoustic properties of the resonator, and a passive region ( 16 , 17 ), which does not directly determine the acoustic properties, wherein the passive region ( 16 , 17 ) of the resonator is irradiated with electromagnetic radiation ( 14 ) if the resonant frequency of the resonator is higher than a desired value specified for the device ( 1 ).

6 . The method according to claim 5 ,

wherein material in the passive region ( 16 , 17 ) is removed as a result of the irradiation with electromagnetic radiation ( 14 ) and deposits uniformly on the entire surface of the component ( 2 ), such that the thickness of the resonator is increased in the resonance region ( 15 ).

7 . The method according to any of the preceding claims,

wherein the component ( 2 ) is encapsulated in a gas atmosphere, wherein the material of the surface of the component ( 2 ) is heated as a result of the irradiation with electromagnetic radiation ( 14 ) and combines with the gas atoms of the gas atmosphere.

8 . The method according to claim 7 ,

wherein the gas reacts with the surface and modifies the latter, or

wherein the irradiating brings about a deposition of the gas molecules on the surface.

9 . The method according to any of the preceding claims,

comprising the following steps:

encapsulating the component ( 2 ) in an atmosphere comprising N 2 , and

trimming the component ( 2 ) by reactive nitriding of the surface of the component ( 2 ) by irradiating with the electromagnetic radiation ( 14 ).

10 . The method according to any of the preceding claims,

comprising the following steps:

encapsulating the component ( 2 ) in an oxygen atmosphere, and

trimming the component ( 2 ) by oxidizing the surface of the component ( 2 ) by irradiating with the electromagnetic radiation ( 14 ).

11 . The method according to any of the preceding claims,

comprising the following steps:

applying a trimming layer ( 9 ) on the surface of the component ( 2 ) prior to encapsulating, and

trimming the component ( 2 ) by increasing the density of the trimming layer ( 9 ) by irradiating with electromagnetic radiation ( 14 ).

12 . The method according to any of the preceding claims,

wherein a femtosecond laser is used for irradiating the component ( 2 ).

13 . The method according to any of the preceding claims,

wherein the component ( 2 ) has a resonator operating with surface acoustic waves and having a metallization in the form of a finger structure comprising electrode fingers ( 30 ), and

wherein the width of an electrode finger ( 30 ) is reduced as a result of the irradiation with electromagnetic radiation ( 14 ).

14 . The method according to any of the preceding claims,

wherein a plurality of resonators are produced on the substrate ( 3 ) and are interconnected to form a duplexer, and

wherein the resonators are jointly encapsulated, wherein the resonators, after encapsulation, are successively trimmed by irradiation with electromagnetic radiation ( 14 ).

15 . The method according to any of the preceding claims,

wherein the MEMS component ( 2 ) is encapsulated in a thin film package, the layer construction of which was produced directly on the substrate ( 3 ) using thin film methods.

16 . An MEMS device ( 1 ) operating with acoustic waves, comprising

an MEMS component ( 2 ) on a substrate ( 3 ), and

a housing layer ( 10 ), which encapsulates the MEMS component ( 2 ) and which is transmissive to electromagnetic radiation ( 14 ) in a wavelength range.

17 . The MEMS device ( 1 ) according to claim 16 ,

wherein the surface of the component ( 2 ) has at least one local region having an increased density that is higher than the density of the rest of the surface of the component ( 2 ).