Clark School Home UMD
Return to Patents

Method for controlling uniformity of thin films fabricated in processing systems


A method for spatial uniformity control in thin film processing is devised which is applicable to any film quality (thickness, composition, microstructure, electrical properties, etc.) as well as to all deposition systems (CVD, PVD, etch, ALD, etc.) where the substrate is rotated to improve uniformity of the deposited thin films. The technique is based on identifying the subspace of all deposition profiles on the stationary substrate that produce uniform films under rotation and then projecting a deposition profile to be controlled onto a sequence of uniformity--producing basis functions spanning that subspace to determine the Nearest Uniformity Producing Profile (NUPP). The process parameters as well as reactor design are optimized in order to minimize uniformity optimization criterion defined as a deviation of a produced deposition profile on the stalled substrate from the NUPP.


Date Issued 


Patent No.