THIN FILM TRANSISTOR AND MANUFACTURING METHOD THEREOF
The present invention relates to a thin film transistor and a manufacturing method thereof. A thin film transistor according to an exemplary embodiment of the present invention includes: a first electrode arranged on a substrate; a second electrode arranged on the substrate and separated from the first electrode; a first ohmic contact arranged on an upper surface of the first electrode; a second ohmic contact arranged on an upper surface of the second electrode; a first buffer member covering a lateral surface of the first electrode and the second electrode; a semiconductor member contacted with an upper surface of the first buffer member, and the first ohmic contact and the second ohmic contact; an insulating layer arranged on the semiconductor member; and a third electrode arranged on the insulating layer, and disposed on the semiconductor member.
1 . A thin film transistor, comprising:
a first electrode arranged on a substrate;
a second electrode arranged on the substrate and separated from the first electrode;
a first ohmic contact arranged on an upper surface of the first electrode;
a second ohmic contact arranged on an upper surface of the second electrode;
a first buffer member covering a lateral surface of the first electrode and a lateral surface of the second electrode;
a semiconductor member contacted with an upper surface of the first buffer member, the first ohmic contact, and the second ohmic contact;
an insulating layer arranged on the semiconductor member; and
a third electrode arranged on the insulating layer and on the semiconductor member.
2 . The thin film transistor of claim 1 , wherein
the first buffer member comprises silicon oxide or silicon nitride.
3 . The thin film transistor of claim 2 , wherein
the first buffer member covers a portion of the upper surface of the first electrode and the second electrode.
4 . The thin film transistor of claim 3 , wherein
the first buffer member covers the entire portion of the substrate located between the first electrode and the second electrode.
5 . The thin film transistor of claim 4 , wherein
the semiconductor member comprises microcrystalline silicon.
6 . The thin film transistor of claim 5 , wherein
a grain diameter of the microcrystalline silicon is less than 10 μm.
7 . The thin film transistor of claim 6 , wherein
the first ohmic contact and the second ohmic contact comprise polysilicon further comprising an impurity.
8 . The thin film transistor of claim 7 , wherein
a plane shape of the first electrode is the same as a plane shape of the first ohmic contact, and a plane shape of the second electrode is the same as a plane shape of the second ohmic contact.
9 . The thin film transistor of claim 8 , further comprising
a second buffer member arranged on the substrate, wherein the first electrode, the second electrode, and the first buffer member are arranged on the second buffer member.
10 . A method for manufacturing a thin film transistor, comprising:
forming a first electrode and a second electrode on a substrate;
respectively forming a first ohmic contact and second ohmic contact on an upper surface of the first electrode and an upper surface of the second electrode;
forming a buffer member on the first ohmic contact, the second ohmic contact, and the substrate;
forming a semiconductor member on the buffer member, the first ohmic contact, and the second ohmic contact;
forming an insulating layer on the semiconductor member; and
forming a third electrode on the insulating layer.
11 . The method of claim 10 , wherein
the semiconductor member comprises microcrystalline silicon.
12 . The method of claim 11 , wherein
the first ohmic contact and the second ohmic contact comprise polysilicon further comprising an impurity.
13 . The method of claim 10 , wherein
the first ohmic contact, the second ohmic contact, the first electrode, and the second electrode are formed through one photolithography step.
14 . The method of claim 10 , further comprising
before forming the first electrode and the second electrode, forming a buffer layer on the substrate.
15 . An organic light emitting device, comprising:
an organic light emitting element to emit light according to a driving current;
a driving transistor connected to the organic light emitting element to flow the driving current according to a data signal, and
a switching transistor to transmit the data signal to the driving transistor,
wherein the driving transistor comprises:
a first electrode arranged on a substrate;
a second electrode arranged on the substrate and separated from the first electrode;
a first ohmic contact arranged on an upper surface of the first electrode;
a second ohmic contact arranged on an upper surface of the second electrode;
a first buffer member covering a lateral surface of the first electrode and a lateral surface of the second electrode;
a semiconductor member contacted with an upper surface of the first buffer member, the first ohmic contact, and the second ohmic contact;
an insulating layer arranged on the semiconductor member; and
a third electrode arranged on the insulating layer and on the semiconductor member.