A method of forming a patterned photoresist layer includes the following operations: (i) forming a patterned photoresist on a substrate; (ii) forming a molding layer covering the patterned photoresist; (iii) reflowing the patterned photoresist in the molding layer; and (iv) removing the molding layer from the reflowed patterned photoresist. In some embodiments, the molding layer has a glass transition temperature that is greater than or equal to the glass transition temperature of the patterned photoresist. In yet some embodiments, the molding layer has a glass transition temperature that is 3° C.-30° C. less than the glass transition temperature of the patterned photoresist.