Manufacturing method of a thin-film transistor of a reverse staggered type

A manufacturing method of thin-film transistors comprising:

• a first step of forming a gate electrode on an electrically insulating substrate;
• a second step of forming a gate insulating film and a semiconductor layer on the gate electrode;
• a third step of forming a single contact-material layer on the semiconductor layer;
• a fourth step of forming an electrode-material layer by forming a conductive electrode material on the contact-material layer, as well as forming a source electrode and a drain electrode by patterning the electrode-material layer using a photoresist pattern;
• and
• a fifth step of patterning a gap section that divides the contact-material layer into the source-electrode side and the drain-electrode side by a plasma etching with etching gases including HCl and CF, using the source electrode and the drain electrode as masks or using the photoresist pattern that has been used for patterning the source electrode and the drain electrodes so that a plurality of conductive contact layers are formed, in order to obtain a construction wherein the source electrode is connected to one side of the contact layer and the drain electrode is connected to the other side of the contact layer.