Methods of manufacturing acoustic wave device with anti-reflection layer
Methods of manufacturing an acoustic wave device are disclosed. An anti-reflection layer can be formed over a conductive layer that is over a piezoelectric layer. The conductive layer can include aluminum, for example. The anti-reflection layer can remain distinct from the conductive layer after a heating process. A photolithography process can pattern an interdigital transducer of the acoustic wave device from one or more interdigital transducer electrode layers that include the conductive layer. The anti-reflection layer can reduce reflection from the conductive layer during the photolithography process.
1. A method of manufacturing an acoustic wave device, the method comprising:
providing an acoustic wave device structure with one or more interdigital transducer electrode layers on a piezoelectric layer, the one or more interdigital transducer electrode layers including a conductive layer;
forming an anti-reflection layer over the conductive layer, the anti-reflection layer including silicon; and
performing a photolithography process to pattern an interdigital transducer electrode from the one or more interdigital transducer electrode layers, the anti-reflection layer reducing reflection from the conductive layer during the photolithography process.
2. The method of claim 1 wherein the conductive layer includes aluminum.
3. The method of claim 1 wherein the anti-reflection layer has a reflectivity of 0.2 or less for light having a wavelength of 365 nanometers.
4. The method of claim 1 wherein the conductive layer has a reflectivity of at least 0.5 for light having a wavelength of 365 nanometers.
5. The method of claim 1 further comprising forming a temperature compensation layer over the anti-reflection layer.
6. The method of claim 1 wherein the anti-reflection layer remains distinct from the conductive layer after a heating process.
7. The method of claim 1 wherein the anti-reflection layer is a silicon oxynitride layer.
8. The method of claim 1 wherein the anti-reflection layer is an amorphous silicon layer.
9. The method of claim 1 wherein the anti-reflection layer is a silicon dioxide layer.
10. The method of claim 1 wherein the anti-reflection layer does not include carbon.
11. The method of claim 1 wherein a line width distribution of the interdigital transducer electrode is 2% of the line width or less.
12. The method of claim 1 wherein the interdigital transducer electrode has a line width in range from 0.25 micrometers to 0.4 micrometers.
13. The method of claim 1 wherein the one or more interdigital transducer electrode layers include an aluminum layer and a molybdenum layer, and the aluminum layer is the conductive layer.
14. A method of manufacturing an acoustic wave device, the method comprising:
providing an acoustic wave device structure with one or more interdigital transducer electrode layers on a piezoelectric layer, the one or more interdigital transducer electrode layers including a conductive layer;
forming an anti-reflection layer over the conductive layer, the anti-reflection layer having a reflectivity of 0.3 or less for light having a wavelength of 365 nanometers, and the anti-reflection layer remaining distinct from the conductive layer after a heating process; and
performing a photolithography process to pattern an interdigital transducer electrode from the one or more interdigital transducer electrode layers, the anti-reflection layer reducing reflection from the conductive layer during the photolithography process.
15. The method of claim 14 wherein the reflectivity of the anti-reflection layer is 0.2 or less for light with the wavelength of 365 nanometers.
16. The method of claim 14 further comprising forming a temperature compensation layer over the interdigital transducer electrode.
17. A method of manufacturing an acoustic wave device, the method comprising:
providing an acoustic wave device structure with one or more interdigital transducer electrode layers on a piezoelectric layer, the one or more interdigital transducer electrode layers including an aluminum layer;
forming an anti-reflection layer over the aluminum layer, the anti-reflection layer remaining distinct from the aluminum layer after a heating process; and
performing a photolithography process to pattern an interdigital transducer electrode from the one or more interdigital transducer electrode layers, the anti-reflection layer reducing reflection from the aluminum layer during the photolithography process.
18. The method of claim 17 wherein a reflectivity of the anti-reflection layer is 0.2 or less for light with a wavelength of 365 nanometers.
19. The method of claim 17 wherein the anti-reflection layer is an amorphous silicon layer having a thickness in a range from 5 nanometers to 15 nanometers.
20. The method of claim 17 wherein the anti-reflection layer is a silicon oxynitride layer having a thickness in a range from 100 nanometers to 120 nanometers.