Scanner linewidth control

摘要

Linewidth (W) variations and bias that result from MEF changes and reticle linewidth variations in a printed substrate are controlled by correcting exposure dose and partial coherence at different spatial locations. In a photolithographic device for projecting an image of a reticle (10) onto a photosensitive substrate (12), an adjustable slit (20) is used in combination with a partial coherence adjuster (18) to vary at different spatial locations the exposure dose received by the photosensitive substrate (12) and partial coherence of the system. The linewidth (W) variance and horizontal and vertical or orientation bias are calculated or measured at different spatial locations with reference to a reticle (10), and a corrected exposure dose and partial coherence is determined at the required spatial locations to compensate for the variance in linewidth (W) and bias on the printed substrate. Improved printing of an image is obtained, resulting in the manufacturer of smaller feature size semiconductor devices and higher yields. <IMAGE>