Peeling method and manufacturing method of flexible device
A peeling method at low cost with high mass productivity is provided. A resin layer having a thickness greater than or equal to 0.1 μm and less than or equal to 3 μm is formed over a formation substrate using a photosensitive and thermosetting material, a transistor including an oxide semiconductor in a channel formation region is formed over the resin layer, the resin layer is irradiated with light using a linear laser device, and the transistor and the formation substrate are separated from each other. A first region and a second region which is thinner than the first region or an opening can be formed in the resin layer. In the case of forming a conductive layer functioning as an external connection terminal or the like to overlap with the second region or the opening of the resin layer, the conductive layer is exposed.
1. A method for manufacturing a flexible device, the method comprising the steps of:
forming a resin layer over a substrate using a photosensitive and thermosetting material, wherein the resin layer has flexibility and comprises a first opening;
forming an insulating layer over the resin layer, wherein the insulating layer comprises a second opening overlapping with the first opening;
forming a transistor and a conductive layer over the insulating layer, wherein the transistor comprises an oxide semiconductor in a channel formation region, and the conductive layer is formed at least partly in the first opening and the second opening;
irradiating the resin layer with light from a substrate side;
after irradiating the resin layer, separating the substrate and the insulating layer from each other, wherein the conductive layer is exposed from the insulating layer through the first opening; and
attaching a flexible printed circuit to the conductive layer exposed from the insulating layer via a connector.
2. The method according to claim 1 ,
wherein the resin layer is formed by heating the photosensitive and thermosetting material at a first temperature, and
wherein the transistor is formed at a temperature lower than or equal to the first temperature.
3. The method according to claim 1 , wherein the resin layer is irradiated with the light using a linear laser device.
4. The method according to claim 1 , wherein the resin layer has a thickness greater than or equal to 0.1 μm and less than or equal to 3 μm.
5. The method according to claim 1 , wherein the resin layer is formed using a photosensitive polyimide resin.
6. The method according to claim 1 , wherein the insulating layer comprises a silicon nitride film and a silicon oxide film over the silicon nitride film.
7. A method for manufacturing a flexible device, the method comprising the steps of:
forming a resin layer over a substrate using a photosensitive and thermosetting material, wherein the resin layer has flexibility and comprises a first region and a second region thinner than the first region;
forming an insulating layer over the resin layer, wherein the insulating layer comprises an opening overlapping with the second region of the resin layer;
forming a transistor and a conductive layer over the insulating layer, wherein the transistor overlaps with the first region of the resin layer and comprises an oxide semiconductor in a channel formation region, and the conductive layer is formed at least partly in contact with the second region of the resin layer through the opening of the insulating layer;
after forming the transistor and the conductive layer, irradiating the resin layer with light from a substrate side;
after irradiating the resin layer, separating the substrate and the insulating layer from each other, wherein the conductive layer is exposed from the insulating layer through the opening; and
attaching a flexible printed circuit to the conductive layer exposed from the insulating layer via a connector.
8. The method according to claim 7 ,
wherein the resin layer is formed by heating the photosensitive and thermosetting material at a first temperature, and
wherein the transistor is formed at a temperature lower than or equal to the first temperature.
9. The method according to claim 7 , wherein the resin layer is irradiated with the light using a linear laser device.
10. The method according to claim 7 , wherein the resin layer has a thickness greater than or equal to 0.1 μm and less than or equal to 3 μm.
11. The method according to claim 7 , wherein the resin layer is formed using a photosensitive polyimide resin.
12. The method according to claim 7 , wherein the insulating layer comprises a silicon nitride film and a silicon oxide film over the silicon nitride film.