US 12,469,725 B2
Method for determining corrective film pattern to reduce semiconductor wafer bow
Ryan J. Stoddard, Seattle, WA (US); Jonathan L. Herlocker, Seattle, WA (US); and Matt McLaughlin, Seattle, WA (US)
Assigned to Delta Design, Inc., Poway, CA (US)
Filed by Delta Design, Inc., Poway, CA (US)
Filed on Jun. 27, 2021, as Appl. No. 17/359,626.
Prior Publication US 2022/0415683 A1, Dec. 29, 2022
Int. Cl. H01L 21/67 (2006.01); G06N 3/045 (2023.01); G06N 3/088 (2023.01)
CPC H01L 21/67288 (2013.01) [G06N 3/045 (2023.01); G06N 3/088 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for generating a corrective film pattern for reducing wafer bow in a semiconductor wafer fabrication process, the method comprising:
measuring, using one or more metrology apparatuses, a bowed semiconductor wafer to produce a wafer bow signature for a predetermined semiconductor fabrication step;
inputting, to a surrogate machine learning model, the wafer bow signature, the surrogate machine learning model comprising:
a forward model comprising a first neural network model configured to take as input corrective film patterns and output corresponding wafer shape transformations, and
an inverse model comprising a second neural network model configured to take as input wafer shape transformations and output corresponding corrective film patterns;
generating, by the surrogate machine learning model, a corrective film pattern corresponding to the wafer bow signature,
wherein the corrective film pattern is adapted for depositing on a semiconductor wafer a corrective film having spatially varying stress signature;
wherein the surrogate machine learning model is trained with a training dataset of target wafer shape transformations and corresponding training corrective film patterns by:
training the forward model using the training corrective film patterns, and
training the inverse model using the target wafer shape transformations and a set of wafer shape transformations output by the trained forward model.