Method for Manufacturing Thin Film Transistor and Display Panel

A method for manufacturing a thin film transistor, comprising the processes of:

• forming a gate electrode on a surface of a substrate;
• forming an insulation film on the surface of the substrate on which the gate electrode is formed;
• forming a first amorphous silicon layer on the surface of the substrate on which the insulation film is formed;
• annealing a required place in the first amorphous silicon layer by irradiating the required place with an energy beam to be changed to a polysilicon layer;
• during the annealing process, forming a removed part having a required shape at other place in association with the required place by irradiating the other place with the energy beam;
• forming a second amorphous silicon layer so as to cover the polysilicon layer;
• forming an n+silicon layer on the second amorphous silicon layer;
• forming a required pattern at the n+silicon layer;
• etching the first amorphous silicon layer, the second amorphous silicon layer and the n+ silicon layer;
• forming a metal layer on the surface of the substrate after the etching process;
• and
• forming source electrode and drain electrode by patterning the metal layer based on a position of a concave formed in the metal layer during forming the metal layer due to a presence of the removed part.

A display panel provided with a thin film transistor and an alignment mark used in a patterning of a source electrode and a drain electrode of the thin film transistor, wherein

• the thin film transistor includes:
• a gate electrode formed on a surface of a substrate;
• an insulation film formed on the substrate and on the gate electrode;
• a polysilicon layer formed at a required place above the gate electrode in a first amorphous silicon layer formed on the insulation film by irradiating the required place with an energy beam;
• an inside portion of the thin film transistor in the first amorphous silicon layer, which is formed above the gate electrode by etching the first amorphous silicon layer;
• a second amorphous silicon layer formed on the inside portion of the thin film transistor in the first amorphous silicon layer and on the polysilicon layer;
• an n+ silicon layer formed on the second amorphous silicon layer;
• and
• the source electrode and the drain electrode formed by patterning a metal layer formed on the surface of the substrate after forming of the n+silicon layer, and the display panel includes:
• a removed part formed at other place which corresponds with the required place and is located in an outside portion of the thin film transistor in the first amorphous silicon layer, the removed part being formed by irradiating the other place with the energy beam;
• and
• a concave formed as the alignment mark in the metal layer due to a presence of the removed part, the metal layer being formed on a portion surrounding the removed part of the first amorphous silicon layer and on the removed part.