Peeling method and manufacturing method of flexible device
A peeling method at low cost with high mass productivity is provided. A silicon layer having a function of releasing hydrogen by irradiation with light is formed over a formation substrate, a first layer is formed using a photosensitive material over the silicon layer, an opening is formed in a portion of the first layer that overlaps with the silicon layer by a photolithography method and the first layer is heated to form a resin layer having an opening, a transistor including an oxide semiconductor in a channel formation region is formed over the resin layer, a conductive layer is formed to overlap with the opening of the resin layer and the silicon layer, the silicon layer is irradiated with light using a laser, and the transistor and the formation substrate are separated from each other.
1. A peeling method comprising:
forming a silicon layer configured to release hydrogen by irradiation with light over a formation substrate;
forming a first layer using a photosensitive material over the silicon layer;
forming a resin layer having an opening by forming the opening in a portion of the first layer which overlaps with the silicon layer by a photolithography method;
forming a transistor including an oxide semiconductor in a channel formation region over the resin layer;
forming a conductive layer to overlap with the opening of the resin layer and the silicon layer;
irradiating the silicon layer with light using a laser; and
separating the transistor and the formation substrate from each other.
2. A peeling method comprising:
forming a silicon layer having an island shape configured to release hydrogen by irradiation with light over a formation substrate;
forming a first layer using a photosensitive material over the formation substrate and the silicon layer;
forming a resin layer having an opening by forming the opening in a portion of the first layer which overlaps with the silicon layer by a photolithography method;
forming a transistor including an oxide semiconductor in a channel formation region over the resin layer;
forming a conductive layer to overlap with the opening of the resin layer and the silicon layer;
irradiating the silicon layer and the resin layer with light using a laser; and
separating the transistor and the formation substrate from each other.
3. The peeling method according to claim 2 , wherein the resin layer is formed to a thickness greater than a thickness of the silicon layer and a thickness less than or equal to 3 μm.
4. The peeling method according to claim 1 , wherein a hydrogenated amorphous silicon layer is formed as the silicon layer.
5. The peeling method according to claim 1 , wherein a linear laser is used as the laser.
6. The peeling method according to claim 1 , wherein the conductive layer is formed using a same material and a same step as an electrode included in the transistor.
7. The peeling method according to claim 1 , wherein the first layer is formed using a solution having a viscosity greater than or equal to 5 cP and less than 100 cP.
8. The peeling method according to claim 1 , wherein the first layer is formed with a spin coater.
9. The peeling method according to claim 1 , wherein the first layer is formed using a thermosetting material.
10. The peeling method according to claim 9 ,
wherein the resin layer is formed by heating the first layer at a first temperature, and
wherein the transistor is formed at a temperature lower than the first temperature.
11. The peeling method according to claim 1 ,
wherein the resin layer is formed to have a thickness greater than or equal to 0 . 1 μm and less than or equal to 3 μm.
12. The peeling method according to claim 1 ,
wherein the silicon layer is irradiated with light from the formation substrate side using the laser.
13. A method for manufacturing a flexible device comprising:
separating the transistor and the formation substrate from each other using the peeling method according to claim 1 , to expose the conductive layer; and
electrically connecting the conductive layer and a circuit board to each other through the opening of the resin layer.
14. A method for manufacturing a flexible device comprising:
separating the transistor and the formation substrate from each other using the peeling method according to claim 1 , to expose the silicon layer;
removing the silicon layer by etching to expose the conductive layer; and
electrically connecting the conductive layer and a circuit board to each other through the opening of the resin layer.
15. A method for manufacturing a flexible device comprising:
separating the transistor and the formation substrate from each other using the peeling method according to claim 2 , to expose the silicon layer; and
electrically connecting the silicon layer and a circuit board to each other.
16. The peeling method according to claim 2 ,
wherein the first layer is formed using a thermosetting material.
17. The peeling method according to claim 16 ,
wherein the resin layer is formed by heating the first layer at a first temperature, and
wherein the transistor is formed at a temperature lower than the first temperature.
18. The peeling method according to claim 2 ,
wherein the resin layer is formed to have a thickness greater than or equal to 0.1 μm and less than or equal to 3 μm.
19. The peeling method according to claim 2 ,
wherein the silicon layer is irradiated with light from the formation substrate side using the laser.
20. A method for manufacturing a flexible device comprising:
separating the transistor and the formation substrate from each other using the peeling method according to claim 2 , to expose the conductive layer; and
electrically connecting the conductive layer and a circuit board to each other through the opening of the resin layer.
21. A method for manufacturing a semiconductor device comprising:
forming a silicon layer over a substrate;
forming a resin layer over the silicon layer;
forming an opening in a portion of the resin layer, the portion overlapping with the silicon layer;
forming a transistor including an oxide semiconductor over the resin layer;
forming a conductive layer in the opening of the resin layer;
irradiating the resin layer with light using a laser from a substrate side; and
separating at least the transistor and the substrate from each other.
22. The method for manufacturing a semiconductor device according to claim 21 ,
wherein the resin layer is formed to a thickness greater than a thickness of the silicon layer.
23. The method for manufacturing a semiconductor device according to claim 21 ,
wherein a linear laser is used as the laser.
24. The method for manufacturing a semiconductor device according to claim 21 ,
wherein the conductive layer is formed using a same material as a source electrode or a drain electrode included in the transistor.
25. The method for manufacturing a semiconductor device according to claim 21 ,
wherein the resin layer is formed using a thermosetting material.
26. The method for manufacturing a semiconductor device according to claim 25 ,
wherein the resin layer is formed by heating at a first temperature, and
wherein the transistor is formed at a second temperature lower than the first temperature.