Wafer alignment system and wafer alignment method

A wafer alignment system comprising:

• a wafer sensor comprising a wafer substrate, a first phase change material pattern provided on the wafer substrate, and a second phase change material pattern, the first phase change material pattern comprising a plurality of first phase change material portions and the second phase change material pattern comprising a plurality of second phase change materials;
• a support member configured to support the wafer sensor and heat the wafer sensor;
• and
• a transfer device configured to transfer the wafer sensor to the support member.

A wafer alignment method comprising:

• loading a wafer sensor onto a support member, the wafer sensor including a wafer substrate and a phase change material layer;
• heating, by the support member, the phase change material layer to a temperature equal to or greater than a crystallization temperature of the phase change material layer;
• causing a phase change in a portion of the phase change material layer contacting the support member based on the heating by the support member;
• and
• unloading the wafer sensor from the support member.