Display element, display device, and electronic device
A display element includes a light-emitting unit of a current drive type, and a drive unit that drives the light-emitting unit, in which the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow through the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit, the drive transistor and the write transistor are formed in a state of being separated by an element isolation region, on a semiconductor substrate, and a capacitance generated in a portion where the drive transistor and the write transistor face each other through the element isolation region functions as at least a part of the capacitance unit.
1. A display element comprising:
a light-emitting unit of a current drive type; and a drive unit that drives the light-emitting unit, wherein
the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow through the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit,
the drive transistor and the write transistor are formed in a state of being separated by an element isolation region, on a semiconductor substrate, and
a capacitance generated in a portion where the drive transistor and the write transistor face each other through the element isolation region functions as at least a part of the capacitance unit.
2. The display element according to claim 1 , wherein
the drive transistor and the write transistor are provided in a well formed in the semiconductor substrate,
the drive transistor includes a first source/drain region to which a feeder line is connected and a second source/drain region connected to one end of the light-emitting unit,
the write transistor includes a first source/drain region to which the signal voltage is supplied externally and a second source/drain region connected to a gate electrode of the drive transistor, and
the second source/drain region of the write transistor and the first source/drain region of the drive transistor are formed to face each other through the element isolation region.
3. The display element according to claim 1 , wherein
the element isolation region is formed by a shallow trench isolation (STI) structure in which an insulator is embedded in a groove dug in a surface of the semiconductor substrate.
4. The display element according to claim 1 , wherein
an impurity diffusion layer that forms a source/drain region of the drive transistor and an impurity diffusion layer that forms a source/drain region of the write transistor are set to have a junction depth of greater than or equal to 1 micrometer.
5. The display element according to claim 1 , wherein
the drive transistor includes a p-channel field effect transistor.
6. The display element according to claim 5 , wherein
the write transistor includes a p-channel field effect transistor.
7. The display element according to claim 2 , wherein
a shield wiring line is provided around a gate wiring line that connects the second source/drain region of the write transistor and the gate electrode of the drive transistor to each other.
8. The display element according to claim 7 , wherein
the shield wiring line is connected to the feeder line.
9. The display element according to claim 2 , wherein
the drive unit further includes a switching transistor connected between the feeder line and the first source/drain region of the drive transistor.
10. The display element according to claim 2 , wherein
the drive unit further includes a switching transistor connected between the one end of the light-emitting unit and the second source/drain region of the drive transistor.
11. The display element according to claim 1 , wherein
the light-emitting unit includes an organic electroluminescence element.
12. A display device comprising
display elements arrayed in a two-dimensional matrix, wherein
the display elements each include a light-emitting unit of a current drive type, and a drive unit that drives the light-emitting unit,
the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow through the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit,
the drive transistor and the write transistor are formed in a state of being separated by an element isolation region, on a semiconductor substrate, and
a capacitance generated in a portion where the drive transistor and the write transistor face each other through the element isolation region functions as at least a part of the capacitance unit.
13. An electronic device comprising
a display device including display elements arrayed in a two-dimensional matrix, wherein
the display elements each include a light-emitting unit of a current drive type, and a drive unit that drives the light-emitting unit,
the drive unit includes a capacitance unit, a drive transistor that causes a current corresponding to a voltage held by the capacitance unit to flow through the light-emitting unit, and a write transistor that writes a signal voltage to the capacitance unit,
the drive transistor and the write transistor are formed in a state of being separated by an element isolation region, on a semiconductor substrate, and
a capacitance generated in a portion where the drive transistor and the write transistor face each other through the element isolation region functions as at least a part of the capacitance unit.