Patent ID: 7959819
Filing Date: 2011-06-14
Classification: H01L

Abstract:
1. A method for reducing aspect ratio dependent etching in a plasma etching process, the method comprising: placing a substrate in a vacuum chamber; setting a desired etch depth difference of different sized features on said substrate; depositing a passivation layer on said substrate by means of a plasma; removing at least a portion of said passivation layer by means of a plasma; etching a material from said substrate by means of a plasma; performing a process loop of repeating the deposition step, the removal step, and the etch step; monitoring the etching of said different sized features on said substrate in real time; measuring a current etch depth difference between said different sized features based on said monitoring step; comparing the current etch depth difference of said different sized features on said substrate to said desired etch depth difference of said different sized features on said substrate; adjusting the process loop step based on said comparison step, thereby minimizing the differences in the etch depth between the monitored different sized features on said substrate; and removing the substrate from the vacuum chamber.