Displays with silicon and semiconducting oxide thin-film transistors

• US 10,707,237 B2
• Filed: 09/10/2018
• Issued: 07/07/2020
• 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): Abdulselam, Abbas I
• Application Number:
  US16/125,973
• Publication Number:
  US 20190006394A1
• Time in Patent Office: 666 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 has a source terminal, a drain terminal, and a gate terminal;

an oxide switching transistor that is directly connected to a node, wherein the node is directly connected to the gate terminal of the drive transistor;

a capacitor having a first plate that is directly connected to the node that is directly connected to the gate terminal of the drive transistor; and

a silicon switching transistor that is directly connected to an anode of the light-emitting diode.

2. The display pixel defined in claim 1, wherein the silicon switching transistor is directly connected between the anode and a signal line.

3. The display pixel defined in claim 1, wherein the silicon switching transistor is directly connected between the anode and a signal line for a column of display pixels.

4. The display pixel defined in claim 1, wherein the first power supply terminal comprises a positive power supply terminal and wherein the second power supply terminal comprises a ground power supply terminal.

5. The display pixel defined in claim 4, wherein the light-emitting diode has a cathode that is coupled to the ground power supply terminal.

6. The display pixel defined in claim 1, wherein the oxide switching transistor is directly connected between the node and a signal line.

7. The display pixel defined in claim 1, wherein the oxide switching transistor is directly connected between the node and a signal line for a column of display pixels.

8. A display pixel comprising:

a positive power supply terminal;

a ground power supply terminal;

a light-emitting diode coupled between the positive power supply terminal and the ground power supply terminal, wherein the light-emitting diode has an anode and a cathode and wherein the cathode is coupled to the ground power supply terminal;

a drive transistor coupled between the positive power supply terminal and the anode of the light-emitting diode, wherein the drive transistor has a gate;

a capacitor having first and second plates, wherein the first plate is directly connected to a node and wherein the node is directly connected to the gate of the drive transistor;

an oxide switching transistor that is directly connected to the node that is directly connected to the gate of the drive transistor; and

a silicon switching transistor that is directly connected between the anode of the light-emitting diode and a signal line.

9. A display pixel comprising:

a positive power supply terminal;

a ground power supply terminal;

a light-emitting diode coupled between the positive power supply terminal and the ground power supply terminal, wherein the light-emitting diode has an anode and a cathode and wherein the cathode is coupled to the ground power supply terminal;

a drive transistor having a gate, a first terminal, and a second terminal, wherein the first terminal is coupled to the positive power supply terminal and the second terminal is coupled to the anode of the light-emitting diode;

a capacitor having first and second plates, wherein the first plate is directly connected to a first node and wherein the first node is directly connected to the gate of the drive transistor;

a first oxide switching transistor that is directly connected to the first node; and

a second oxide switching transistor that is directly connected to a second node, wherein the second node is directly connected to the second terminal of the drive transistor.

10. The display pixel defined in claim 9, wherein the second plate is directly connected to the second node.