3D NAND staircase CD control by using interferometric endpoint detection

Patent metadata

Field	Value
Publication number	US-9240359-B2
Application number	US-201414326442-A
Country	US
Kind code	B2
Filing date	Jul 8, 2014
Priority date	Jul 8, 2013
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

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.

First claim

The invention claimed is:

1. A method of determining a photoresist trimming endpoint for forming stair-like structures on a substrate, comprising:
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 op…

Assignees

• Applied Materials Inc

Inventors

• Lian Lei

Classifications

• H10P76/204

  Electricity · mapped topic

• H10P74/203

  Electricity · mapped topic

• H10P50/287

  Electricity · mapped topic

• H10P74/238 Primary

  Electricity · mapped topic

• H10D88/01

  Electricity · mapped topic