Alignment marks and manufacturing method for the same

A manufacturing method for alignment marks comprising the steps of:

• forming a thin-film transistor including at least a gate electrode, a gate insulating film, a semiconductor thin film, source and drain electrodes on a wafer;
• forming alignment reference marks by using the same materials as those of at least one of the gate electrode, the semiconductor film, and the source and drain electrodes in an area other than a formation area for the thin-film transistor at the same time when the gate electrode, the semiconductor film and the source and drain electrodes are formed:
• forming red filter alignment reference marks comprising a red filter so as to cover the alignment reference marks;
• and
• then, performing alignment of the following step pattern based on the alignment reference marks below the red filter alignment marks.