Process for increasing resolution of photolithographic images

Abstract

The present invention describes conformable masking techniques which can be successfully made and used in a practical manufacturing environment while providing increased resolution of photolithographic images while eliminating all manner of defects that might presently be encountered in the masks currently used in the semiconductor industry. In the present invention a body is first coated with a positive photoresist overcoated with a conformable mask which is exposed through a fixed mask and developed to define a replica of the fixed mask, together with all its defects. The underlying photoresist is then exposed to light through developed openings in the conformable mask. The conformable mask is then stripped and a new conformable mask laid down. This new conformable mask is now exposed through a second fixed mask having the same image as the first fixed mask, but presumably with different defects and developed to define a replica of the second mask. The underlying photoresist is again exposed through the second conformable mask and developed. As a result of using two independently defined conformable masks clear image defects in the fixed masks are prevented from being reproduced in the underlying photoresist and are not doubly exposed. Only desired regions in the underlying photoresist are doubly exposed.