CN-122002864-A - Thin film transistor, method of manufacturing the same, and display device including the same

Abstract

The present disclosure relates to a thin film transistor, a method of manufacturing the same, and a display device including the same. The present disclosure provides a thin film transistor including a gate electrode, an active layer, a source electrode, and a drain electrode, wherein the active layer includes a first channel portion overlapping the source electrode, a second channel portion overlapping the drain electrode, and a connection portion connecting the first channel portion and the second channel portion, and the connection portion is a region that is electrically conductive. In addition, a method of manufacturing a thin film transistor and a display device including the thin film transistor are disclosed.

Inventors

• CUI SHENGZHU
• GAO YONGXIAN
• Zhang Zaiman
• LIU ZHIXI

Assignees

• 乐金显示有限公司

Dates

Publication Date

20260508

Application Date

20250826

Priority Date

20241101

Claims (20)

1. 1. A thin film transistor, the thin film transistor comprising: A gate electrode; An active layer spaced apart from and at least partially overlapping the gate electrode; an interlayer insulating layer on the active layer; A source electrode on the interlayer insulating layer, the source electrode being connected to the active layer, and A drain electrode on the interlayer insulating layer and spaced apart from the source electrode, the drain electrode being connected to the active layer, Wherein the active layer includes: a first channel portion overlapping the source electrode and the gate electrode, the first channel portion being located between the source electrode and the gate electrode; a second channel portion overlapping the drain electrode and the gate electrode, the second channel portion being located between the drain electrode and the gate electrode, and A connection portion between the first channel portion and the second channel portion, the connection portion connecting the first channel portion and the second channel portion, Wherein the connection is a region that is electrically conductive.
2. 2. The thin film transistor of claim 1, wherein the connection portion is doped with a dopant and the connection portion has a dopant concentration that is higher than the dopant concentration of the first channel portion and the dopant concentration of the second channel portion.
3. 3. The thin film transistor according to claim 1, wherein the connection portion does not overlap with the source electrode and the drain electrode.
4. 4. The thin film transistor of claim 1, wherein the active layer further comprises: a first contact portion in contact with the source electrode, an And a second contact portion that contacts the drain electrode.
5. 5. The thin film transistor of claim 4, wherein the first channel portion is located between the connection portion and the first contact portion, and the second channel portion is located between the connection portion and the second contact portion.
6. 6. The thin film transistor according to claim 1, wherein the connection portion overlaps with the gate electrode.
7. 7. The thin film transistor according to claim 1, wherein at least a portion of the connection portion does not overlap with the gate electrode.
8. 8. The thin film transistor of claim 1, wherein the gate electrode comprises: a first gate electrode overlapping the first channel portion and the source electrode, and And a second gate electrode overlapping the second channel portion and the drain electrode.
9. 9. The thin film transistor of claim 8, wherein at least a portion of the connection portion does not overlap the first gate electrode and the second gate electrode.
10. 10. The thin film transistor according to claim 1, wherein the interlayer insulating layer is located on the connection portion.
11. 11. The thin film transistor according to claim 1, wherein at least a portion of the connection portion does not overlap with the interlayer insulating layer.
12. 12. The thin film transistor of claim 1, further comprising: And a cover layer in contact with the connection portion, the cover layer having a reduction characteristic that reduces a characteristic of the connection portion.
13. 13. The thin film transistor of claim 12, wherein the capping layer comprises at least one of titanium, molybdenum, aluminum, indium, and zinc.
14. 14. A thin film transistor, the thin film transistor comprising: A gate electrode; An active layer spaced apart from and at least partially overlapping the gate electrode, and A source electrode connected to the active layer, Wherein the active layer includes: A channel portion overlapping the source electrode and the gate electrode; A contact portion in contact with the source electrode, and A connection portion which does not overlap with the source electrode, Wherein the channel portion is located between the connection portion and the contact portion, and the connection portion is a region that is electrically conductive.
15. 15. The thin film transistor of claim 14, wherein the connection portion is doped with a dopant and the connection portion has a higher dopant concentration than the channel portion.
16. 16. The thin film transistor of claim 14, further comprising: A gate insulating layer on the gate electrode, the gate insulating layer being between the gate electrode and the active layer, Wherein a first end of the connection portion connected to the channel portion has a first height higher than a second end of the connection portion disposed on a side surface of the gate insulating layer.
17. 17. A method of manufacturing a thin film transistor, the method comprising: forming a gate electrode on a substrate; Forming an active layer on the gate electrode, the active layer being spaced apart from and at least partially overlapping the gate electrode; forming an interlayer insulating layer on the active layer, the interlayer insulating layer having a contact hole formed therein; forming a source electrode and a drain electrode on the interlayer insulating layer, and The active layer is selectively electrically conductive using the source electrode and the drain electrode as masks.
18. 18. The manufacturing method according to claim 17, wherein the selectively conducting the active layer includes conducting a region of the active layer that does not overlap the source electrode and the drain electrode, the conducting region of the active layer being a connection portion.
19. 19. The manufacturing method according to claim 17, wherein a region of the active layer overlapping the source electrode is not electrically conductive and is a first channel portion during the selectively electrically conductive step, and a region of the active layer overlapping the drain electrode is not electrically conductive and is a second channel portion during the selectively electrically conductive step.
20. 20. The method of manufacturing of claim 17, wherein selectively conducting the active layer comprises dopant doping the active layer.

Description

Thin film transistor, method of manufacturing the same, and display device including the same Technical Field The present disclosure relates to a thin film transistor, a method for manufacturing the same, and a display device including the thin film transistor. Background Thin film transistors can be manufactured on a glass or plastic substrate, and thus are widely used as switching elements or driving elements in display devices such as liquid crystal display devices or organic light emitting devices. The thin film transistor may be classified into an amorphous silicon thin film transistor using amorphous silicon as an active layer, a polycrystalline silicon thin film transistor using polycrystalline silicon as an active layer, and an oxide semiconductor thin film transistor using an oxide semiconductor as an active layer, according to a material constituting the active layer. Among these, an oxide semiconductor thin film transistor having high mobility and large resistance change according to oxygen content has an advantage that desired characteristics can be easily obtained. Since an oxide constituting the active layer can be formed at a relatively low temperature during a manufacturing process of the oxide semiconductor thin film transistor, manufacturing cost is low. In addition, since oxide semiconductors are transparent due to the nature of oxides, they are also advantageous in achieving transparent display. The high resolution display includes a large number of thin film transistors. In order to arrange a large number of thin film transistors in a given area, the size of the thin film transistors must be reduced. However, when the size of the thin film transistor is reduced, the channel length is also shortened, which may deteriorate the operation stability of the thin film transistor or cause characteristic deviation between the plurality of thin film transistors, which may deteriorate the display quality of the display device. In order for a thin film transistor to operate stably, the channel must have an effective channel length greater than a specific value. In the case of a thin film transistor having a coplanar structure, control of the region to be electrically conductive is important for ensuring the channel length. In the thin film transistor, a phenomenon in which a region which is electrically conductive penetrates into a channel may occur. If the length of the conductive region penetrating into the channel is not constant, the effective channel length of the thin film transistor is not constant, and characteristic variation may occur between the thin film transistors. In particular, if the effective channel length is not constant in a short channel thin film transistor having a short channel length, characteristic variation between thin film transistors becomes remarkable, making it difficult to manufacture a large area panel. Therefore, in order to manufacture a high-resolution display device having excellent display quality, it is necessary to increase the integration density of thin film transistors by shortening the channel length of the thin film transistors while ensuring uniformity of characteristics between the thin film transistors. Disclosure of Invention One embodiment of the present disclosure provides a technique that can easily form a short channel by using a source electrode and a drain electrode as masks in a conductivity process. One embodiment of the present disclosure provides a technique of using a source electrode and a drain electrode as masks in a conductivity process so that a channel portion can be defined by the source electrode and the drain electrode. In addition, one embodiment of the present disclosure provides a technique that allows the channel portion to be defined by self-alignment due to the channel portion being defined by the source electrode and the drain electrode limit. One embodiment of the present disclosure provides a thin film transistor having a short channel of a short length while having excellent uniformity. One embodiment of the present disclosure provides a method of manufacturing a thin film transistor in which a source electrode and a drain electrode are used as masks for a conductive process. Another embodiment of the present disclosure is to provide a display device including a thin film transistor. In one embodiment, a thin film transistor includes a gate electrode, an active layer spaced apart from and at least partially overlapping the gate electrode, an interlayer insulating layer on the active layer, a source electrode on the interlayer insulating layer, the source electrode connected to the active layer, and a drain electrode on the interlayer insulating layer and spaced apart from the source electrode, the drain electrode connected to the active layer, wherein the active layer includes a first channel portion overlapping the source electrode and the gate electrode, the first channel portion between the source electrode and the