MEMS device with dummy-area utilization for pressure enhancement

1. A sensor comprising:

a microelectromechanical systems (MEMS) substrate disposed over an integrated chip (IC), wherein the IC at least partially defines a first cavity and at least partially defines a second cavity, and wherein the first cavity has a first operating pressure and the second cavity has a second operating pressure that is different than the first operating pressure;

a sensor area and a dummy area disposed in the first cavity, wherein the sensor area comprises a movable portion of the MEMS substrate, and wherein the dummy area comprises a fixed portion of the MEMS substrate; and

a pressure enhancement structure disposed in the dummy area.

2. The sensor of claim 1 , wherein:

the pressure enhancement structure is a getter structure configured to decrease a pressure of the first cavity from a sealing pressure to the first operating pressure; and

the sealing pressure corresponds to a pressure at which the first cavity is sealed.

3. The sensor of claim 2 , wherein both the first cavity and the second cavity are sealed at the sealing pressure.

4. The sensor of claim 1 , wherein:

the pressure enhancement structure is an outgassing structure configured to increase a pressure of the first cavity from a sealing pressure to the first operating pressure; and

the sealing pressure corresponds to a pressure at which the first cavity is sealed.

5. The sensor of claim 4 , wherein both the first cavity and the second cavity are sealed at the sealing pressure.

6. The sensor of claim 5 , wherein:

the IC comprises a dielectric layer disposed over a chip substrate; and

the outgassing structure contacts both the dielectric layer and a lower surface of the fixed portion of the MEMS substrate.

7. The sensor of claim 6 , wherein the outgassing structure partially defines a sidewall of the first cavity.

8. The sensor of claim 1 , wherein:

the pressure enhancement structure is an embedded chamber that is in fluid communication with the first cavity; and

the embedded chamber is at least partially defined by the MEMS substrate.

9. The sensor of claim 8 , wherein:

a sum of a volume of the first cavity and a volume of the embedded chamber is different than a volume of the second cavity.

10. The sensor of claim 9 , wherein the volume of the first cavity and the volume of the second cavity are substantially the same.

11. The sensor of claim 8 , wherein a sum of a volume of the first cavity and a volume of the embedded chamber is substantially the same as a volume of the second cavity.

12. The sensor of claim 8 , wherein:

the IC comprises a chip substrate;

a dielectric layer is disposed vertically between the MEMS substrate and the chip substrate; and

the embedded chamber is partially defined by the MEMS substrate and is partially defined by a dielectric layer.

13. A sensor comprising:

a dielectric layer disposed over a first substrate, wherein the dielectric layer at least partially defines a first cavity and a second cavity;

a second substrate disposed over the dielectric layer, wherein the second substrate has a first movable portion and a first fixed portion that are both disposed in the first cavity, and wherein the second substrate has a second movable portion and a second fixed portion that are both disposed in the second cavity; and

a first pressure enhancement structure disposed in the first fixed portion.

14. The sensor of claim 13 , wherein the first cavity has a first operating pressure and the second cavity has a second operating pressure that is different than the first operating pressure.

15. The sensor of claim 13 , wherein the dielectric layer is bonded to the second substrate.

16. The sensor of claim 13 , wherein the first pressure enhancement structure is configured to change a pressure of the first cavity from a sealing pressure to a first operating pressure that is different than the sealing pressure.

17. The sensor of claim 13 , further comprising:

a third substrate disposed over both the first substrate and the second substrate, wherein:

first sidewalls of the third substrate partially define an upper portion of the first cavity;

second sidewalls of the third substrate partially define an upper portion of the second cavity;

first sidewalls of the dielectric layer partially define a lower portion of the first cavity;

second sidewalls of the dielectric layer partially define a lower portion of the second cavity;

the upper portion of the first cavity is in fluid communication with the lower portion of the first cavity; and

the upper portion of the second cavity is in fluid communication with the lower portion of the second cavity.

18. The sensor of claim 13 , further comprising:

a second pressure enhancement structure disposed in the second fixed portion.

19. A sensor comprising:

one or more semiconductor devices disposed on a chip substrate;

a dielectric structure disposed over the chip substrate and the one or more semiconductor devices, wherein the dielectric structure at least partially defines a first cavity and a second cavity;

a metallization structure disposed in the dielectric structure and electrically coupled to the one or more semiconductor devices;

a microelectromechanical systems (MEMS) substrate disposed over the dielectric structure and the chip substrate;

a first sensor area and a dummy area disposed in the first cavity, wherein the first sensor area comprises a first movable portion of the MEMS substrate, and wherein the dummy area comprises a fixed portion of the MEMS substrate;

a second sensor area disposed in the second cavity, wherein the second sensor area comprises a second movable portion of the MEMS substrate; and

a pressure enhancement structure disposed in the dummy area.

20. The sensor of claim 19 , wherein the first cavity has a first operating pressure and the second cavity has a second operating pressure that is different than the first operating pressure.