A method of patterning a thin film. The method includes forming a mask on a film to be patterned. The film is then etched in alignment with the mask to form a patterned film having a pair of laterally opposite sidewalls. A protective layer is formed on the pair of laterally opposite sidewalls. Next, the mask is removed from above the patterned film. After removing the mask from the patterned film, the protective layer is removed from the sidewalls.