Displays with embedded MEMS sensors and related methods

• US 8,558,250 B2
• Filed: 07/27/2011
• Issued: 10/15/2013
• Est. Priority Date: 01/27/2009
• Status: Active Grant

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona Board of Regents (University of Arizona)
• Inventors: Venugopal, Sameer M., Lakamraju, Narendra V.
• Primary Examiner(s): Nguyen, Thinh T
• Application Number:
  US13/192,357
• Publication Number:
  US 20120175644A1
• Time in Patent Office: 811 Days
• Field of Search: 257/88, 257/419, 257/E27.121, 257/E33.055, 438/24, 438/53
• US Class Current: 257/88
• CPC Class Codes: G01L 19/083 electrical
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

Embodiments of displays with embedded MEMS sensors and related methods are described herein. Other embodiments and related methods are also disclosed herein.

Claims

1. A semiconductor device, comprising:

a substrate;

a first MEMS device of one or more MEMS devices over the substrate;

a pixel array over the substrate, the pixel array comprising one or more pixels; and

a display comprising at least a portion of the one or more pixels of the pixel array; and

one or more pressure sensors;

wherein;

a first pressure sensor of the one or more pressure sensors comprises the first MEMS device;

the first pressure sensor is configured to detect when the display is contacted proximate to the first pressure sensor;

the first MEMS device comprises;

a capacitor having;

an electrically conductive material located over the substrate;

a sensor membrane movably suspended over the electrically conductive material; and

a first dielectric located over the electrically conductive material and under the sensor membrane;

and

a round wall structure configured to support the sensor membrane over a gap between the electrically conductive material and the sensor membrane;

and

the sensor membrane is configured to move towards the electrically conductive material when the display is contacted proximate to the first pressure sensor.

2. The semiconductor device of claim 1, wherein:

the first pressure sensor further comprises a second MEMS device of the one or more MEMS devices; and

a sensitivity of the first pressure sensor is defined at least in part by a capacitance of the first MEMS device and a capacitance of the second MEMS device.

3. The semiconductor device of claim 1, wherein:

the sensor membrane comprises a second electrically conductive material.

4. The semiconductor device of claim 1, wherein:

the first pressure sensor is proximate to a first pixel set of the one or more pixels; and

the first pressure sensor is coupled to a control module configured to identify the first pixel set when the display is contacted proximate to the first pressure sensor.

5. The semiconductor device of claim 4, wherein:

the first pixel set comprises a single pixel of the one or more pixels proximate to the first pressure sensor.

6. The semiconductor device of claim 4, wherein:

the first pixel set comprises a plurality of pixels of the one or more pixels within a predetermined distance from the first pressure sensor.

7. The semiconductor device of claim 4, wherein:

the first pixel set comprises 9 pixels proximate to the first pressure sensor.

8. The semiconductor device of claim 1, wherein:

the one or more MEMS devices are formed simultaneously along with the pixel array.

9. The semiconductor device of claim 1, wherein:

the first MEMS device is located within a first pixel of the one or more pixels of the pixel array; and

the first pixel comprises an aperture ratio of at least approximately 50%.

10. The semiconductor device of claim 1, wherein:

the first MEMS device is located over a pixel-free area of the substrate adjacent to at least a first pixel of the one or more pixels of the pixel array.

11. The semiconductor device of claim 1, wherein:

the first MEMS device is located within a first pixel of the one or more pixels of the pixel array; and

the first MEMS device occupies at most approximately 25% of an area of the first pixel.

12. The semiconductor device of claim 1, wherein:

the substrate is flexible.

13. The semiconductor device of claim 1, wherein:

the substrate comprises at least one of;

a PEN material, a PET material, a PES material, a polyimide, a polycarbonate, a cyclic olefin copolymer, or a liquid crystal polymer.

14. The semiconductor device of claim 1, wherein:

the first MEMS device comprises a radius of approximately 50 micrometers to approximately 75 micrometers.

15. The semiconductor device of claim 1, wherein:

the first MEMS device comprises at least one of;

an active capacitance of approximately 3.0 picofarads to approximately 2.0 picofarads;

or

an inactive capacitance of approximately 2.0 picofarads to approximately 1.5 picofarads.

16. The semiconductor device of claim 1, wherein:

the pixel array comprises a pixel size of approximately 240*240 micrometers squared.

17. The semiconductor device of claim 1, wherein:

the first MEMS device of the one or more MEMS devices is located within a first pixel of the one or more pixels of the pixel array;

a second MEMS device of the one or more MEMS devices is located within a second pixel of the one or more pixels of the pixel array;

the first MEMS device is proximate to a first corner of the first pixel;

the second MEMS device is proximate to a second corner of the second pixel; and

the first corner of the first pixel is immediately adjacent to the second corner of the second pixel.

18. The semiconductor device of claim 17, wherein:

a third MEMS device of the one or more MEMS devices is located within a third pixel of the one or more pixels of the pixel array;

a fourth MEMS device of the one or more MEMS devices is located within a fourth pixel of the one or more pixels of the pixel array;

the third MEMS device is proximate to a third corner of the third pixel;

the fourth MEMS device is proximate to a fourth corner of the fourth pixel; and

the first, second, third, and fourth corners are immediately adjacent to each other.

19. The semiconductor device of claim 18, wherein:

the first pressure sensor comprises the first, second, third, and fourth MEMS devices.

20. A method comprising:

providing a substrate;

forming a pixel array over the substrate, the pixel array comprising one or more pixels;

forming a MEMS array over the substrate;

providing a display comprising at least a portion of the one or more pixels; and

providing one or more pressure sensors;

wherein;

forming the MEMS array over the substrate comprises;

forming at least a first MEMS device of the one or more MEMS devices;

a first pressure sensor of the one or more pressure sensors comprises the first MEMS device;

the first pressure sensor is configured to detect when the display is contacted proximate to the first pressure sensor;

the first MEMS device comprises;

a capacitor having;

an electrically conductive layer over the substrate;

a sensor membrane movably suspended over the electrically conductive layer; and

a first dielectric located over the electrically conductive layer and under the sensor membrane;

and

a round wall structure configured to support the sensor membrane over a gap between the electrically conductive layer and the sensor membrane;

and

the sensor membrane is configured to move towards the electrically conductive layer when the display is contacted proximate to the first pressure sensor.

21. The method of claim 20, wherein:

forming the pixel array occurs simultaneously with forming the MEMS array.

22. The method of claim 20, wherein:

forming at least the first MEMS device comprises;

providing a sacrificial structure over the electrically conductive layer; and

providing the sensor membrane over the sacrificial structure, the sensor membrane comprising a second electrically conductive layer.

23. The method of claim 22, wherein:

providing the sacrificial structure comprises;

providing a sacrificial layer over the electrically conductive layer; and

providing the round wall structure at a perimeter of the sacrificial layer.

24. The method of claim 23, wherein:

forming at least the first MEMS device comprises;

anchoring the sensor membrane over the round wall structure of the sacrificial structure;

forming one or more openings through the sensor membrane; and

removing the sacrificial layer via the one or more openings of the sensor membrane.

25. The method of claim 22, wherein:

forming at least the first MEMS device comprises;

configuring the sensor membrane to vary a capacitance of the first MEMS device as the sensor membrane is flexed relative to the electrically conductive layer.

26. The method of claim 20, wherein:

forming at least the first MEMS device further comprises;

forming the first MEMS device within a first pixel of the one or more pixels of the pixel array.

27. The method of claim 20, wherein:

forming the first MEMS device comprises;

forming the first MEMS device over a pixel-free area of the substrate adjacent to at least a first pixel of the one or more pixels of the pixel array.

28. The method of claim 20, further comprising:

providing a control module coupled to the MEMS array;

wherein;

forming the pixel array comprises;

a first pixel set of the one or more pixels of the pixel array, the first pixel set proximate to the first MEMS device;

providing the control module comprises;

configuring the control module to correlate the first pixel set with the first MEMS device;

and

forming at least the first MEMS device comprises;

configuring the first MEMS device to generate a signal for the control module when the display is contacted proximate to the first pixel set.

29. The method of claim 28, wherein:

forming the MEMS array further comprises;

forming a second MEMS device of the one or more MEMS devices proximate to the first pixel set; and

configuring the second MEMS device in combination with the first MEMS device to generate the signal for the control module.

30. The method of claim 29, wherein:

the signal is based on a combined capacitance of the first and second MEMS devices.

31. The method of claim 28, wherein:

providing the control module further comprises;

configuring the control module to interpret the signal as an actuation of a marker displayed proximate to the first pixel set.

32. The method of claim 28, wherein:

providing the control module further comprises;

configuring the control module to interpret a change in capacitance of the first MEMS device as the signal.

33. The method of claim 28, wherein:

forming the pixel array comprises;

providing each pixel of the first pixel set within a predetermined distance from the first MEMS device.

34. The method of claim 20, wherein:

providing the substrate comprises;

providing the substrate to be flexible.

38. The method of claim 20, wherein:

forming the MEMS array over the substrate comprises;

interspersing the MEMS array with the pixel array over the substrate.

35. A semiconductor device, comprising:

a substrate;

a first MEMS device of one or more MEMS devices over the substrate;

a pixel array over the substrate, the pixel array comprising one or more pixels;

and

one or more pressure sensors;

wherein;

a first pressure sensor of the one or more pressure sensors comprises the first MEMS device;

the first MEMS device comprises a capacitor having;

an electrically conductive material located over the substrate;

a sensor membrane movably suspended over the electrically conductive material; and

a round wall structure configured to support the sensor membrane over a gap between the electrically conductive material and the sensor membrane;

and

the sensor membrane is configured to move towards the electrically conductive material when the display is contacted proximate to the first pressure sensor.

36. The semiconductor device of claim 35, wherein:

the first pressure sensor further comprises a second MEMS device of the one or more MEMS devices; and

a sensitivity of the first pressure sensor is defined at least in part by a capacitance of the first MEMS device and a capacitance of the second MEMS device.

37. The semiconductor device of claim 35, further comprising:

a display comprising at least a portion of the one or more pixels of the pixel array;

wherein;

the substrate is flexible;

the first pressure sensor is configured to detect when the display is contacted proximate to the first pressure sensor;

the capacitor of the first MEMS device further comprises;

the first MEMS device comprises a capacitor having;

a first dielectric located over the electrically conductive material and under the sensor membrane;

the sensor membrane comprises a second electrically conductive material;

the first pressure sensor is proximate to a first pixel set of the one or more pixels; and

the first pressure sensor is configured to be coupled to a control module configured to identify the first pixel set when the display is contacted proximate to the first pressure sensor.