Transistor and manufacturing method thereof

A method for manufacturing a transistor, the method comprising:

• forming a semiconductor layer on a substrate;
• forming a gate electrode overlapping the semiconductor layer;
• and
• forming a source electrode and a drain electrode electrically connected to the semiconductor layer,
• wherein the forming the semiconductor layer comprises inputting a first precursor, a second precursor, and a reactant into a chamber to form a semiconductor material,
• wherein the semiconductor material comprises a second material doped to a first material,
• wherein the first material comprises a compound expressed as XYa of a Chemical Formula,
• wherein X is one of molybdenum (Mo), tungsten (W), zirconium (Zr), or rhenium (Re),
• wherein Y is one of sulfur (S), selenium (Se), or tellurium (Te),
• wherein a is a natural number that is equal to or greater than 1,
• wherein the second material comprises at least one of tungsten (W), hafnium (Hf), tantalum (Ta), titanium (Ti), platinum (Pt), nickel (Ni), gallium (Ga), or zirconium (Zr),
• wherein the second material is substitutionally doped at the X site of the first material expressed as XYa of the Chemical Formula, and
• wherein the second material comprises an element that is different from the first material, and 5.0 wt % to 7.5 wt % of the second material is included with respect to an entire content of the semiconductor layer.