Method of forming process substrate using thin glass substrate and method of fabricating flat display device using the same

A method for fabricating a liquid crystal display device, comprising:

• providing a first substrate and a second substrate, the first and second substrates having respectively a first surface and a second surface;
• attaching a third auxiliary substrate to the first surface of the second substrate;
• contacting a second auxiliary substrate to the second surface of the second substrate in a vacuum state;
• forming an atmospheric state at the out region of the contacted second substrate and second auxiliary substrate to press the contacted second substrate and second auxiliary substrate by the atmospheric pressure in order to attach the second substrate and the second auxiliary substrate;
• separating the third auxiliary substrate from the first surface of the second substrate to form a second process substrate;
• forming a gate line, a data line, a thin film transistor and a pixel electrode on the first surface of the first substrate;
• forming a color filter layer on the first substrate of the second substrate of the second process substrate;
• attaching the first surface of the first substrate and the first surface of the second process substrate to each other, thereby forming a liquid crystal panel;
• and
• separating the second auxiliary substrate from the liquid crystal panel.