Method of fine patterning a thin film and method of manufacturing a display substrate using the method

1. A method of manufacturing a display substrate, the method comprising:

forming a first metal layer on a base substrate;

forming a first photoresist pattern on the first metal layer, the first photoresist pattern having first photoresist pattern widths;

forming a first fine photo pattern by ashing the first photoresist pattern to provide first fine photo pattern widths that are smaller than the first photoresist pattern widths;

forming a first signal line by etching the first metal layer exposed through the first fine photo pattern;

forming a first insulation layer on the base substrate having the first signal line formed thereon;

forming a second metal layer on the first insulation layer;

forming a second photoresist pattern on the second metal layer, the second photoresist pattern having a partial residue part, the partial residue part being thinner than other portions of the second photoresist pattern;

forming a second fine photo pattern by ashing the second photoresist pattern to form an opening corresponding to the partial residue part;

forming a second signal line by etching the second metal layer exposed through the second fine photo pattern; and

forming a pixel electrode in a pixel area of the base substrate, the pixel electrode being electrically connected to the first or second signal line.

2. The method of claim 1 , wherein a width of each of the first and second signal lines is about 0.1 μm to about 5.0 μm.

3. The method of claim 1 , wherein forming the pixel electrode comprises:

forming a transparent conductive layer on the base substrate having the first and second signal lines formed thereon;

forming a third photoresist pattern on the transparent conductive layer of the pixel area, the third photoresist pattern comprising a plurality of first thickness parts and a plurality of second thickness parts thicker than the first thickness parts;

forming a third fine photo pattern in which the first thickness parts are removed by ashing the third photoresist pattern; and

forming a plurality of fine electrodes of a bar shape, which forms the pixel electrode, by removing the transparent conductive layer exposed through the third fine photo pattern.

4. The method of claim 1 , wherein forming the pixel electrode comprises:

forming a transparent conductive layer on the base substrate having the first and second signal lines formed thereon;

forming a third photoresist pattern on the transparent conductive layer of the pixel area, the third photoresist pattern comprising a plurality of openings exposing the transparent conductive layer;

forming a third fine photo pattern having the plurality of openings with expanded widths by ashing the third photoresist pattern; and

forming a plurality of fine electrodes of a bar shape, which forms the pixel electrode, by removing the transparent conductive layer exposed through the third fine photo pattern.

5. The method of claim 4 , further comprising: forming a common electrode disposed between the pixel electrode and the base substrate.

6. The method of claim 1 , further comprising:

forming a second insulation layer between a base substrate having the first and second signal lines formed thereon and the pixel electrode;

forming a fourth photoresist pattern on the second insulation layer, the fourth photoresist pattern comprising a first thickness part and a second thickness part thicker than the first thickness part;

removing the second thickness part to form a third fine photo pattern exposing a portion of the second insulation layer; and

removing the second insulation layer exposed through the third fine photo pattern to form a contact hole.

7. The method of claim 1 , wherein the partial residue part is formed by irradiating a portion of the second photoresist pattern and removing the portion by a developing solution.