Structure and method of manufacture for acoustic resonator or filter devices using improved fabrication conditions and perimeter structure modifications
A method of manufacture for an acoustic resonator or filter device. In an example, the present method can include forming metal electrodes with different geometric areas and profile shapes coupled to a piezoelectric layer overlying a substrate. These metal electrodes can also be formed within cavities of the piezoelectric layer or the substrate with varying geometric areas. Combined with specific dimensional ratios and ion implantations, such techniques can increase device performance metrics. In an example, the present method can include forming various types of perimeter structures surrounding the metal electrodes, which can be on top or bottom of the piezoelectric layer. These perimeter structures can use various combinations of modifications to shape, material, and continuity. These perimeter structures can also be combined with sandbar structures, piezoelectric layer cavities, the geometric variations previously discussed to improve device performance metrics.
1. A method for fabricating an acoustic resonator device, the method comprising:
providing a substrate having a substrate surface region;
forming a single crystal piezoelectric layer overlying the substrate surface region, the piezoelectric layer having a top piezoelectric surface region and a bottom piezoelectric surface region;
forming a topside energy confinement structure overlying the top piezoelectric surface region, the topside energy confinement structure being characterized by a topside structure geometric area and a topside structure perimeter, the topside energy confinement structure having at least one portion removed forming a topside structure break region;
forming a topside metal electrode overlying the top piezoelectric surface region and within the topside energy confinement structure, the topside metal electrode being characterized by a topside electrode geometric area;
forming a backside trench within the substrate exposing the bottom piezoelectric surface region, the backside trench underlying the topside metal electrode, the backside trench being characterized by a cavity geometric area; and
forming a topside sandbar structure overlying the top piezoelectric surface region within a vicinity of the topside structure break region; wherein the topside sandbar structure is spatially configured outside the topside structure perimeter of the topside energy confinement structure.
2. The method of claim 1 wherein the topside metal electrode is formed adjacent to the topside energy confinement structure.
3. The method of claim 1 wherein the topside sandbar structure is spatially configured with a gap having a distance of about 0.1 um to about 100 um to the topside metal electrode.
4. The method of claim 1 wherein the topside energy confinement structure comprises a dielectric material, a metal material, or a combination of dielectric and metal materials.
5. The method of claim 1 wherein the topside energy confinement structure comprises a castellation pattern characterized by a repeated castellation shape, wherein the castellation shape includes a square, a triangle, a polygonal shape, or a non-polygonal shape.
6. The method of claim 1 wherein the topside sandbar structure comprises a dielectric material, a metal material, or a combination of dielectric and metal materials.
7. The method of claim 1 wherein the topside sandbar structure comprises a straight sandbar structure, a curved sandbar structure, or an angled sandbar structure.
8. The method of claim 1 wherein each of the topside electrode geometric area, the topside structure geometric area, and the cavity geometric area includes a circle, an ellipses, skew non-polygonal shapes, irregular shapes, or a polygonal shape having n sides, where n is greater than or equal to three; wherein the topside electrode geometric area, the topside structure geometric area, and the cavity geometric area can be characterized by geometric areas having similar or dissimilar shapes.
9. A method for fabricating an acoustic resonator device, the method comprising:
providing a substrate having a substrate surface region;
forming a single crystal piezoelectric layer overlying the substrate surface region, the piezoelectric layer having a top piezoelectric surface region and a bottom piezoelectric surface region;
forming a backside trench within the substrate exposing the bottom piezoelectric surface region, the backside trench being characterized by a cavity geometric area;
forming a backside energy confinement structure underlying the bottom piezoelectric surface region, the backside energy confinement structure being characterized by a backside structure geometric area and a backside structure perimeter, the backside energy confinement structure having at least one portion removed forming a backside structure break region; and
forming a backside metal electrode underlying the bottom piezoelectric surface region and within the backside energy confinement structure, the backside metal electrode being characterized by a backside electrode geometric area.
10. The method of claim 9 wherein the backside metal electrode is formed adjacent to the backside energy confinement structure.
11. The method of claim 9 further comprising forming a backside sandbar structure underlying the bottom piezoelectric surface region within a vicinity of the backside structure break region; wherein the backside sandbar structure is spatially configured outside the backside structure perimeter of the backside energy confinement structure.
12. The method of claim 11 wherein the backside sandbar structure is spatially configured with a gap having a distance of about 0.1 um to about 100 um to the backside metal electrode.
13. The method of claim 9 wherein the backside energy confinement structure comprises a dielectric material, a metal material, or a combination of dielectric and metal materials.
14. The method of claim 9 wherein the backside energy confinement structure comprises a castellation pattern characterized by a repeated castellation shape, wherein the castellation shape includes a square, a triangle, a polygonal shape, or a non-polygonal shape.
15. The method of claim 11 wherein the backside sandbar structure comprises a dielectric material, a metal material, or a combination of dielectric and metal materials.
16. The method of claim 11 wherein the backside sandbar structure comprises a straight sandbar structure, a curved sandbar structure, or an angled sandbar structure.
17. The method of claim 9 wherein each of the backside electrode geometric area, the backside structure geometric area, and the cavity geometric area includes a circle, an ellipses, skew non-polygonal shapes, irregular shapes, or a polygonal shape having n sides, where n is greater than or equal to three; wherein the backside electrode geometric area, the backside perimeter structure geometric area, and the cavity geometric area can be characterized by geometric areas having similar or dissimilar shapes.
18. A method for fabricating an acoustic resonator device, the method comprising:
providing a substrate having a substrate surface region;
forming a single crystal piezoelectric layer overlying the substrate surface region, the piezoelectric layer having a top piezoelectric surface region and a bottom piezoelectric surface region;
forming a topside energy confinement structure overlying the top piezoelectric surface region, the topside energy confinement structure being characterized by a topside structure geometric area and a topside structure perimeter, the topside energy confinement structure having at least one portion removed forming a topside structure break region;
forming a topside metal electrode overlying the top piezoelectric surface region and within the topside energy confinement structure, the topside metal electrode being characterized by a topside electrode geometric area;
forming a topside sandbar structure overlying the top piezoelectric surface region within a vicinity of the topside structure break region;
forming a backside trench within the substrate exposing the bottom piezoelectric surface region, the backside trench underlying the topside metal electrode and the topside micro-trench, the backside trench being characterized by a cavity geometric area;
forming a backside energy confinement structure underlying the bottom piezoelectric surface region, the backside energy confinement structure being characterized by a backside structure geometric area, the backside energy confinement structure having at least one portion removed forming a backside structure break region;
forming a backside metal electrode underlying the bottom piezoelectric surface region and within the backside energy confinement structure, the backside metal electrode being characterized by a backside electrode geometric area; and
forming a backside sandbar structure underlying the bottom piezoelectric surface region within a vicinity of the backside structure break region.
19. The method of claim 18 wherein each of the topside sandbar structure and the backside sandbar structure comprises a straight sandbar structure, a curved sandbar structure, or an angled sandbar structure.
20. A method for fabricating an acoustic resonator device, the method comprising:
providing a substrate having a substrate surface region;
forming a single crystal piezoelectric layer overlying the substrate surface region, the piezoelectric layer having a top piezoelectric surface region and a bottom piezoelectric surface region;
forming a topside energy confinement structure overlying the top piezoelectric surface region, the topside energy confinement structure being characterized by a topside structure geometric area and a topside structure perimeter, the topside energy confinement structure having at least one portion removed forming a topside structure break region;
forming a topside metal electrode overlying the top piezoelectric surface region and within the topside energy confinement structure, the topside metal electrode being characterized by a topside electrode geometric area; and
forming a backside trench within the substrate exposing the bottom piezoelectric surface region, the backside trench underlying the topside metal electrode, the backside trench being characterized by a cavity geometric area;
wherein the topside energy confinement structure comprises a castellation pattern characterized by a repeated castellation shape, wherein the castellation shape includes a square, a triangle, a polygonal shape, or a non-polygonal shape.