Displays with silicon and semiconducting oxide thin-film transistors

• US 10,096,622 B2
• Filed: 10/06/2017
• Issued: 10/09/2018
• Est. Priority Date: 08/26/2013
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Gupta, Vasudha, Choi, Jae Won, Chang, Shih Chang, Tsai, Tsung-Ting, Park, Young Bae
• Primary Examiner(s): CHEN, WEN YING PATTY
• Application Number:
  US15/727,475
• Publication Number:
  US 20180033805A1
• Time in Patent Office: 368 Days
• CPC Class Codes: G02F 1/13452 Conductors connecting driver circuitry and terminals of panels
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/13624 having more than one switching element per pixel
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/13685 Top gates
• CPC Class Codes: G02F 2202/104 poly-Si
• CPC Class Codes: H01L 27/1222 with a particular composition, shape or crystalline structure of the active layer
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/126 Shielding, e.g. light-blocking means over the TFTs

Abstract

An electronic device may include a display having an array of display pixels on a substrate. The display pixels may be organic light-emitting diode display pixels or display pixels in a liquid crystal display. In an organic light-emitting diode display, hybrid thin-film transistor structures may be formed that include semiconducting oxide thin-film transistors, silicon thin-film transistors, and capacitor structures. The capacitor structures may overlap the semiconducting oxide thin-film transistors. Organic light-emitting diode display pixels may have combinations of oxide and silicon transistors. In a liquid crystal display, display driver circuitry may include silicon thin-film transistor circuitry and display pixels may be based on oxide thin-film transistors. A single layer or two different layers of gate metal may be used in forming silicon transistor gates and oxide transistor gates. A silicon transistor may have a gate that overlaps a floating gate structure.

Claims

1. A display pixel comprising:

a first power supply terminal;

a second power supply terminal;

a light-emitting diode coupled between the first and second power supply terminals;

a drive transistor coupled between the first power supply terminal and the light-emitting diode, wherein the drive transistor is an oxide transistor;

a first switching transistor that is coupled to a gate of the drive transistor, wherein the first switching transistor is an oxide transistor;

a capacitor coupled between a first node that is interposed between the first switching transistor and the drive transistor and a second node that is interposed between the drive transistor and the light-emitting diode; and

a second switching transistor coupled to the second node, wherein the second switching transistor is a silicon transistor.

2. The display pixel defined in claim 1, wherein the first switching transistor is coupled between the gate of the drive transistor and a vertical line.

3. The display pixel defined in claim 2, wherein the vertical line is associated with a respective column of display pixels.

4. The display pixel defined in claim 1, wherein the second switching transistor is a PMOS silicon transistor.

5. The display pixel defined in claim 1, wherein the second switching transistor is coupled between the second node and a vertical line.

6. The display pixel defined in claim 1, wherein the drive transistor has a channel formed from a layer of semiconducting oxide.

7. The display pixel defined in claim 6, wherein the first switching transistor has a channel formed from a layer of semiconducting oxide.

8. The display pixel defined in claim 7, wherein the second switching transistor has a channel formed from a layer of polysilicon.

9. A display pixel comprising:

a first power supply terminal;

a second power supply terminal;

a light-emitting diode coupled between the first and second power supply terminals;

a drive transistor coupled between the first power supply terminal and the light-emitting diode, wherein the drive transistor is an oxide transistor;

a first switching transistor that is coupled to a gate of the drive transistor, wherein the first switching transistor is an oxide transistor; and

a capacitor coupled between a first node that is interposed between the first switching transistor and the drive transistor and a second node that is interposed between the drive transistor and the light-emitting diode.

10. The display pixel defined in claim 9, wherein the first switching transistor has a gate that receives a control signal from a gate line.

11. The display pixel defined in claim 9, wherein the first switching transistor is coupled between the gate of the drive transistor and a vertical line.

12. The display pixel defined in claim 9, wherein the drive transistor has a channel formed from a layer of semiconducting oxide.

13. The display pixel defined in claim 12, wherein the first switching transistor has a channel formed from a layer of semiconducting oxide.

14. The display pixel defined in claim 9, further comprising:

a second switching transistor coupled to the second node.

15. A display pixel comprising:

a first power supply terminal;

a second power supply terminal;

a light-emitting diode coupled between the first and second power supply terminals;

a drive transistor coupled between the first power supply terminal and the light-emitting diode, wherein the drive transistor is an oxide transistor;

a first switching transistor that is coupled to a gate of the drive transistor;

a capacitor coupled between a first node that is interposed between the first switching transistor and the drive transistor and a second node that is interposed between the drive transistor and the light-emitting diode; and

a second switching transistor coupled to the second node, wherein the second switching transistor is a silicon transistor.

16. The display pixel defined in claim 15, wherein the first switching transistor is coupled between the gate of the drive transistor and a vertical line.

17. The display pixel defined in claim 15, wherein the second switching transistor is a PMOS silicon transistor.

18. The display pixel defined in claim 15, wherein the second switching transistor is coupled between the second node and a vertical line.

19. The display pixel defined in claim 15, wherein the drive transistor has a channel formed from a layer of semiconducting oxide.

20. The display pixel defined in claim 19, wherein the second switching transistor has a channel formed from a layer of polysilicon.