Alignment method and alignment system

An alignment system for sequentially supplying substrates each having zones, to be aligned and being disposed in accordance with a predetermined array, and for aligning the zones in each substrate with a predetermined reference position sequentially, said system comprising:

• position measuring means for measuring in sequence deviations in the positions of zones of a first substrate with respect to positions determined in accordance with the predetermined array, and for detecting the actual array of the zones through the measurement;
• parameter determining means for determining, in terms of a predetermined transformation parameter, the relationship between the predetermined array and the actual array detected with said position measuring means, and for determining a transformation parameter for the first substrate effective to minimize an error between the predetermined array and the detected actual array;
• memory means for detecting and storing an error between the actual array and an array determined in accordance with the transformation parameter of the first substrate;
• and
• aligning means for aligning, with respect to the predetermined reference position, a second substrate having zones of substantially the same array as the first substrate, by using the stored error as an alignment correction value.

An exposure method for sequentially supplying wafers each having zones, to be aligned and being disposed in accordance with a predetermined array, and for aligning zones in each wafer with a predetermined reference position sequentially, and for projecting a pattern of a reticle onto the zones of each wafer for exposure thereof, said method comprising:

• a first step for measuring in sequence deviations in the positions of zones of a first wafer with respect to positions determined in accordance with the predetermined array, and for detecting the actual array of the zones through the measurement;
• a second step for determining, in terms of a predetermined transformation parameter, the relationship between the predetermined array and the actual array detected in said first step, and for determining a transformation parameter for the first wafer effective to minimize an error between the predetermined array and the detected actual array;
• a third step for detecting and storing an error between the actual array and an array determined in accordance with the transformation parameter of the first wafer;
• a fourth step for aligning, with respect to the predetermined reference position, a second wafer having zones of substantially the same array as the first wafer, by using the stored error as an alignment correction value, and then for transferring the pattern of the reticle onto the second wafer;
• and
• a fifth step of projecting a pattern of a reticle onto the zones of each wafer.

An exposure apparatus for sequentially supplying wafers each having zones, to be aligned and being disposed in accordance with a predetermined array and for aligning zones in each wafer with a predetermined reference position sequentially, and for projecting a pattern of a reticle upon each wafer for exposure thereof, said apparatus comprising:

• a movable stage on which each wafer can be placed;
• position measuring means for measuring in sequence deviations of positions of zones of a first wafer with respect to positions determined in accordance with the predetermined array, and for detecting the actual array of the zones through the measurement;
• parameter determining means for determining, in terms of a predetermined transformation parameter, the relationship between the predetermined array and the actual array detected with said position measuring means, and for determining a transformation parameter for the first wafer effective to minimize an error between the predetermined array and the detected actual array;
• memory means for detecting and storing an error between the actual array and an array determined in accordance with the transformation parameter of the first wafer;
• and
• aligning means for aligning, with respect to the predetermined reference position, a second wafer having zones of substantially the same array as the first wafer, by using the stored error as an alignment correction value;
• projecting means for projecting a pattern of a reticle upon the first wafer;
• and
• a control system for transferring the pattern of the reticle onto the second wafer being aligned with respect to the reference position through said aligning means.