Wafer cutting apparatus

A wafer cutting apparatus, comprising:

• a stage to support a wafer;
• a cutter to irradiate the wafer with a beam along a first direction to cut the wafer;
• a first sensor on a first side of the cutter to measure a first spaced distance between the wafer and the cutter;
• a second sensor, on a second side opposing the first side of the cutter, to measure a second spaced distance between the wafer and the cutter;
• and
• a corrector to correct an offset between the first sensor and the second sensor based on a comparison of the measured first spaced distance and the measured second spaced distance, wherein
• the cutter, the first sensor, and the second sensor are disposed along the first direction, and wherein
• at least one of the first or second sensors are to operate while the cutter cuts the wafer.