Method of processing a substrate

A method of processing a substrate, which is adapted to form a new resist pattern by dissolving a photoresist of a used resist pattern which has been used as an etching mask for forming a backing layer having edge portions and includes at least thicker film portions and thinner film portions both formed by a half exposing process, the method comprising the steps of:

• providing a re-developing process to the used photoresist pattern to remove the thinner film portions from the photoresist pattern;
• and
• further providing a re-developing process to the used photoresist pattern to dissolve the thicker film portions formed on the backing layer, to have the dissolved photoresist pass through a stepped portion formed at each edge portion of the backing layer, and masking a predetermined area of lower layers under the backing layer;
• wherein in the step of masking the predetermined area by the photoresist,
• the photoresist is dissolved in a first dissolving-speed mode on the backing layer, and
• the photoresist is then dissolved in a second dissolving-speed mode after the photoersist to be dissolved reaches the stepped portion, the second dissolving-speed mode being slower than the first dissolving-speed mode.