Overhang pattern for advanced OLED patterning
Embodiments described herein relate to a device. The device includes a substrate, a plurality of overhang structures disposed over the substrate, and a plurality of sub-pixels. Each overhang structure includes a first structure, a second structure disposed over the first structure, and adjacent overhangs. The first structure includes an upper section and a lower section. The upper section includes a sidewall parallel to a surface normal of the substrate. The lower section includes a top surface with a first width equal to a second width of a lower surface of the upper section and a lower surface of the first structure having a third width greater than the second width of the lower surface of the upper section. The adjacent overhangs are defined by an overhang extension of the second structure extending laterally past the upper surface of the first structure.
1 . A device, comprising:
a substrate;
a plurality of overhang structures disposed over the substrate, each overhang structure having:
a first structure, the first structure comprising:
an upper section, the upper section comprising:
a sidewall parallel to a surface normal of the substrate; and
an upper surface of the first structure;
a lower section, the lower section comprising:
a top surface with a first width equal to a second width of a lower surface of the upper section; and
a lower surface of the first structure having a third width greater than the second width of the lower surface of the upper section and extending a first distance past an upper surface of the first structure;
a second structure disposed over an upper surface of the first structure; and
adjacent overhangs, each overhang defined by an overhang extension of the second structure extending laterally past the upper surface of the first structure, wherein the overhang extension of the second structure extends a second distance past the upper surface of the first structure, wherein the first distance is equal to the second distance; and
a plurality of sub-pixels, each sub-pixel comprising:
an anode;
an organic light emitting diode (OLED) material disposed over the anode; and
a cathode disposed over the OLED material.
2 . The device of claim 1 , wherein the upper section of the first structure is deposited at a first temperature and the lower section of the first structure is deposited at a second temperature.
3 . The device of claim 2 , wherein the first temperature is about 100° C. to about 200° C., and the second temperature is about 250° C. to about 350° C.
4 . The device of claim 1 , wherein an encapsulation layer is disposed over and extends under at least a portion of the overhang.
5 . The device of claim 1 , wherein the second structure comprises copper (Cu), chromium (Cr), aluminum (Al), aluminum neodymium (AlNd), molybdenum (Mo), molybdenum tungsten (MoW), titanium (Ti), or combinations thereof.
6 . The device of claim 1 , wherein a passivation layer is disposed over the substrate, and wherein the first structure is disposed over the passivation layer.
7 . The device of claim 1 , wherein the upper section is an amorphous silicon (α-Si) and the lower section is an α-Si, a silicon nitride (SiN x ), or a silicon oxide (SiO 2 ).
8 . A device, comprising:
a substrate;
a plurality of overhang structures disposed over the substrate, each overhang structure having:
a first structure, comprising:
an upper surface;
a lower surface; and
a plane of a sidewall, wherein:
the upper surface has a first width greater than a second width of the first structure at the plane; and
the lower surface has a third width greater than the second width of the first structure at the plane;
a second structure disposed over an upper surface of the first structure; and
adjacent overhangs, each overhang defined by an overhang extension of the second structure extending laterally past an upper surface of the first structure; and
a plurality of sub-pixels, each sub-pixel comprising:
an anode;
an organic light emitting diode (OLED) material disposed over the anode; and
a cathode disposed over the OLED material.
9 . The device of claim 8 , wherein the overhang extension of the second structure extends a first distance past an upper surface of the first structure, extends a second distance past an edge of a lower surface of the first structure, and extends a third distance from the plane of the sidewall.
10 . The device of claim 9 , wherein the first distance is about 30 nm to about 90 nm, the second distance is less than about 50 nm, and the third distance is about 50 nm to about 150 nm.
11 . The device of claim 8 , wherein the second structure comprises copper (Cu), chromium (Cr), aluminum (Al), aluminum neodymium (AlNd), molybdenum (Mo), molybdenum tungsten (MoW), titanium (Ti), or combinations thereof.
12 . The device of claim 8 , wherein the second structure comprises amorphous silicon (a-Si), silicon nitride (Si 3 N 4 ), silicon oxide (SiO 2 ), silicon oxynitride (Si 2 N 2 O), or combinations thereof.
13 . The device of claim 8 , wherein the overhang structures are disposed over a plurality of pixel structures, and wherein the pixel structures are disposed over the substrate.
14 . The device of claim 8 , wherein an encapsulation layer is disposed over and extends under at least a portion of the overhang.
15 . A device, comprising:
a substrate;
a plurality of overhang structures disposed over the substrate, each overhang structure having:
a first structure, comprising:
an upper surface; and
a lower surface, wherein the lower surface has a width greater than the upper surface;
a second structure disposed over an upper surface of the first structure; and
adjacent overhangs, each overhang defined by an overhang extension of the second structure extending laterally past an upper surface of the first structure; and
a plurality of sub-pixels, each sub-pixel comprising:
an anode;
an organic light emitting diode (OLED) material disposed over the anode; and
a cathode disposed over the OLED material.
16 . The device of claim 15 , wherein a bottom surface of the second structure extends a first distance past an upper surface of the first structure, and extends a second distance past an edge of a lower surface of the first structure.
17 . The device of claim 16 , wherein the first distance is about 140 nm to about 200 nm and the second distance is about 140 nm to about 200 nm.
18 . The device of claim 15 , wherein the second structure comprises copper (Cu), chromium (Cr), aluminum (Al), aluminum neodymium (AlNd), molybdenum (Mo), molybdenum tungsten (MoW), titanium (Ti), or combinations thereof.
19 . The device of claim 15 , wherein the second structure comprises amorphous silicon (a-Si), silicon nitride (Si 3 N 4 ), silicon oxide (SiO 2 ), silicon oxynitride (Si 2 N 2 O), or combinations thereof.
20 . The device of claim 15 , wherein a passivation layer is disposed over the substrate, and wherein the first structure is disposed over the passivation layer.