SYSTEM FOR SENSING STEPPER FOCUS AND TILT TO RESTRAIN DIFFERENCE OF CRITICAL DIMENSION BETWEEN INNER SHOT AND EDGE SHOT

摘要

PURPOSE: A system for sensing focus and tilt of a stepper is provided to restrain the difference of CD(Critical Dimension) between an inner shot and an edge shot and to obtain exact focus/tilt data by controlling light transmitting and receiving parts according to the size of diverse exposure shot. CONSTITUTION: A system for sensing focus and tilt of a stepper includes a light transmitting part(6), a light receiving part(7), driving parts(9,10), and a control part(8). The light transmitting part irradiates light to a shot region so as to form a channel region. The light receiving part receives the light reflected from the channel region. The driving parts adjust the moving range corresponding to the shot size of the channel region by controlling the light transmitting and receiving part. The control part controls the adjustment of the moving range.