Displays with silicon and semiconducting oxide thin-film transistors
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.
1. A display pixel comprising:
a light-emitting diode;
a plurality of transistors that is configured to control the light-emitting diode, wherein the plurality of transistors includes a semiconducting oxide transistor having a first gate and a silicon transistor having a second gate and wherein the semiconducting oxide transistor and the silicon transistor are switching transistors;
a capacitor coupled to the plurality of transistors, wherein the capacitor has an electrode layer;
a layer of metal that is patterned to form the second gate and the electrode layer, wherein the semiconducting oxide transistor comprises a layer of semiconducting oxide and wherein the first gate and the layer of semiconducting oxide are overlapping;
a first dielectric layer formed over the layer of metal; and
a second dielectric layer formed over the first dielectric layer.
2. The display pixel defined in claim 1 , wherein the first gate comprises molybdenum.
3. The display pixel defined in claim 1 , wherein the first gate comprises molybdenum and a refractory metal that is different from molybdenum.
4. The display pixel defined in claim 3 , wherein the refractory metal that is different from molybdenum comprises tungsten.
5. The display pixel defined in claim 1 , wherein the capacitor is a storage capacitor configured to store data associated with a frame.
6. The display pixel defined in claim 1 , wherein an additional layer of metal is interposed between the first and second dielectric layers.
7. A display pixel comprising:
a light-emitting diode;
a plurality of transistors that is configured to control the light-emitting diode, wherein the plurality of transistors includes a semiconducting oxide transistor and a silicon transistor;
a capacitor coupled to the plurality of transistors;
a layer of metal that forms a gate for the silicon transistor and an electrode layer for the capacitor;
a first dielectric layer formed over the layer of metal; and
a second dielectric layer formed over the first dielectric layer.
8. The display pixel defined in claim 7 , wherein an additional layer of metal is interposed between the first and second dielectric layers.
9. The display pixel defined in claim 7 , wherein the first dielectric layer is silicon oxide.
10. The display pixel defined in claim 7 , wherein the first dielectric layer is silicon nitride.
11. The display pixel defined in claim 7 , wherein the capacitor is a storage capacitor configured to store data associated with a frame.
12. The display pixel defined in claim 7 , wherein the semiconducting oxide transistor comprises an additional gate that comprises molybdenum.
13. A display that comprises a display pixel, wherein the display pixel comprises:
a light-emitting diode;
a semiconducting oxide transistor having a first gate, wherein the semiconducting oxide transistor is coupled between a voltage line and a terminal of the drive transistor;
a silicon transistor having a second gate;
a capacitor having an electrode layer;
a layer of metal that is patterned to form the second gate and the electrode layer, wherein the semiconducting oxide transistor comprises a layer of semiconducting oxide and wherein the first gate and the layer of semiconducting oxide are overlapping;
a first dielectric layer formed over the layer of metal; and
a second dielectric layer formed over the first dielectric layer.
14. The display defined in claim 13 , wherein the first gate comprises molybdenum.
15. The display defined in claim 13 , wherein the first gate comprises molybdenum and a metal that is different from molybdenum.
16. The display defined in claim 13 , wherein the refractory metal that is different from molybdenum comprises tungsten.
17. The display defined in claim 13 , wherein the capacitor is a storage capacitor configured to store data associated with a frame.
18. The display defined in claim 13 , wherein an additional layer of metal is interposed between the first and second dielectric layers.