Question

In semiconductor manufacturing, the root causes of defects can be attributed to

photolithography. Could you explain the reasons?

Answer 1

There are many kinds of defects. Some of impinge during photolithography steps/stages.The silicon can have a flaw in the crystal structure due to photolithography. Too heavy, too less doped is also the reason. There may be a non-silicon impurity. There might be a speck of dust.   The mask might have a flaw. The mask might be slightly misaligned with previous masked layers. The oven might have been a bit too hot or too cold. The diffusion gas might have an impurity. An airborne virus or bacteria might have landed on the wafer.