Thin film transistor and display panel including the same

A display panel, comprising:

• a substrate;
• a thin film transistor on the substrate, comprising:
• a gate electrode on the substrate;
• a channel layer overlapping the gate electrode;
• a gate dielectric layer disposed between the gate electrode and the channel layer;
• a source electrode and a drain electrode electrically connected to the channel layer;
• a passivation layer overlying the source electrode, the drain electrode, and the gate dielectric layer;
• a via hole through the passivation layer;
• and
• a conductive pattern on the passivation layer to serve as a pixel electrode, wherein the conductive pattern is in contact with the drain electrode through the via hole,
• wherein the channel layer comprises an oxide semiconductor;
• wherein the channel layer includes two contact portions being in contact with the source electrode and the drain electrode, respectively, and a non-contact portion located between the two contact portions, and
• wherein one of the two contact portions has a first thickness in a first direction, the non-contact portion has a second thickness in the first direction, the first direction is perpendicular to a surface of the substrate, and the first thickness is greater than the second thickness.