| 摘要 |
Embodiments of the present disclosure provide methods for forming stair-like structures with accurate profiles control in manufacturing three dimensional (3D) stacking of semiconductor chips using precise photoresist trimming process endpoint control. In one example, a method of determining a photoresist trimming endpoint for forming stair-like structures on a substrate includes performing a trimming process on a substrate to trim a patterned photoresist layer disposed on a film stack from a first width to a second width in a processing chamber, wherein the patterned photoresist layer exposes a portion of the film stack uncovered by the patterned photoresist layer during the trimming process, directing an optical signal to a surface of the patterned photoresist layer while trimming the patterned photoresist layer, collecting a return reflected optical signal reflected from the photoresist layer, and determining a trimming endpoint by analyzing the return optical signal reflected from the photoresist layer. |
