Method of manufacturing display apparatus and display apparatus manufactured through the method
A method of manufacturing a display apparatus includes: preparing a substrate including a pixel circuit region and a driving circuit region; forming a first active layer at the pixel circuit region; forming a second active layer at the driving circuit region; forming gate electrodes that overlap the first active layer and the second active layer, respectively, with a gate insulating layer disposed therebetween; forming a first insulating layer covering the first and second active layers; forming a first contact hole that passes through the first insulating layer until a portion of the first active layer is exposed; heat-treating the substrate where the first insulating layer, in which the first contact hole is formed, is formed; and forming a second contact hole that passes through the first insulating layer disposed on the heat-treated substrate until a portion of the second active layer is exposed.
1. A method of manufacturing a display apparatus, the method comprising the steps of:
preparing a substrate including a pixel circuit region and a driving circuit region;
forming a first active layer at the pixel circuit region of the substrate;
forming a second active layer at the driving circuit region of the substrate;
forming gate electrodes that overlap the first active layer and the second active layer, respectively, with a gate insulating layer disposed therebetween;
forming a first insulating layer on the substrate so as to cover the first active layer and the second active layer;
forming a first contact hole that passes through the first insulating layer until a portion of the first active layer, among the first active layer and the second active layer, is exposed;
heat-treating the substrate where the first insulating layer, having the first contact hole passing through it, is formed; and
forming a second contact hole that passes through the first insulating layer disposed on the heat-treated substrate until a portion of the second active layer is exposed;
wherein the first active layer and the second active layer are formed during a same mask process and comprise a same material, and wherein a hydrogen concentration of the first active layer that is adjacent to the first contact hole is less than a hydrogen concentration of the second active layer that is adjacent to the second contact hole.
2. The method of claim 1 , wherein a hydrogen concentration of a first part of the first insulating layer that is adjacent to the first contact hole is less than a hydrogen concentration of a second part of the first insulating layer that is adjacent to the second contact hole.
3. The method of claim 1 , wherein:
the gate insulating layer is disposed between the first and second active layers and the first insulating layer; and
each of the first contact hole and the second contact hole passes through the gate insulating layer and the first insulating layer.
4. The method of claim 3 , wherein a hydrogen concentration of a first part of the gate insulating layer that is adjacent to the first contact hole is less than a hydrogen concentration of a second part of the gate insulating layer that is adjacent to the second contact hole.
5. The method of claim 1 , further comprising the step of doping the first active layer and the second active layer with same impurities.
6. A display apparatus, comprising:
a substrate including a pixel circuit region and a driving circuit region;
a first thin film transistor disposed in the pixel circuit region of the substrate and comprising a first active layer, a first gate electrode, a first source electrode, and a first drain electrode;
a display device connected to one of the first source electrode and the first drain electrode;
a second thin film transistor disposed in the driving circuit region of the substrate and comprising a second active layer, a second gate electrode, a second source electrode, and a second drain electrode; and
a first insulating layer covering the first active layer and the second active layer;
wherein the first insulating layer includes a first contact hole that exposes a portion of the first active layer, and a second contact hole that exposes a portion of the second active layer; and
wherein the first active layer and the second active layer comprise a same material, and a hydrogen concentration of a first part of the first active layer that is adjacent to the first contact hole is less than a hydrogen concentration of a second part of the second active layer that is adjacent to the second contact hole.
7. The apparatus of claim 6 , wherein a hydrogen concentration of a first part of the first insulating layer that is adjacent to the first contact hole is less than a hydrogen concentration of a second part of the first insulating layer that is adjacent to the second contact hole.
8. The apparatus of claim 6 , further comprising:
a gate insulating layer disposed between the first and second active layers and the first insulating layer;
wherein each of the first contact hole and the second contact hole passes through the gate insulating layer and the first insulating layer.
9. The apparatus of claim 8 , wherein a hydrogen concentration of a first part of the gate insulating layer that is adjacent to the first contact hole is less than a hydrogen concentration of a second part of the gate insulating layer that is adjacent to the second contact hole.
10. The apparatus of claim 6 , wherein:
the first active layer includes a source region and a drain region doped with first impurities,
the second active layer includes a source region and a drain region doped with second impurities, and
the first impurities are of same materials as the second impurities.
11. The apparatus of claim 6 , further comprising the first active layer and the second active layer doped with the same impurities.