Method of etching a pixel electrode

A method for manufacturing a thin film transistor array panel, comprising:

• forming a gate line on a substrate;
• forming a gate insulating layer covering the gate line;
• forming a semiconductor layer on the gate insulating layer;
• forming a data line and a drain electrode on the semiconductor layer;
• forming a passivation layer having a contact hole on the data line;
• forming a first pixel electrode connected to the drain electrode through the contact hole on the passivation layer;
• removing the first pixel electrode by using an etchant;
• and
• forming a second pixel electrode connected to the drain electrode through the contact hole on the passivation layer,
• wherein the etchant comprises an inorganic acid, an ammonium (NH4+)-containing compound, a cyclic amine compound, and water,
• wherein the inorganic acid comprises H2SO4 and another inorganic acid, and a concentration of H2SO4 is less than half of a concentration of the another inorganic acid.