Optimization of blended virtual and actual metrology schemes

Jae Yeon Claire Baek; Costas J. Spanos

doi:10.1117/12.916313

5 April 2012 Optimization of blended virtual and actual metrology schemes

Proceedings Volume 8324, Metrology, Inspection, and Process Control for Microlithography XXVI; 83241K (2012) https://doi.org/10.1117/12.916313
Event: SPIE Advanced Lithography, 2012, San Jose, California, United States

Abstract

There are two competing costs that occur in off line semiconductor processing metrology. One is the cost of operating the metrology tool, and the other is the loss in terms of processing cost and yield due to the time lapse between the occurrence and the correction of a process fault. Virtual metrology (VM) is an alternative scheme which takes data produced by the processing tool in real time (e.g. plasma etching data during isolation trench formation) and predicts an outcome of the wafer (e.g. critical dimension of the trench) utilizing an empirical model. Although VM prediction quality is not as good as that of conventional metrology, it produces an immediate, low cost prediction for each wafer going through a process. In real life, we envision that practical metrology schemes will involve a synergistic blend of VM and actual metrology, the latter being used for the needed periodic recalibration of the VM empirical model. In this work, we formulate the costs associated with Type I and Type II errors that result from a blended metrology scheme, and propose a general framework that can be used to quickly lead to the optimal design of such schemes given the characteristics of the process in question. We also explore the effects of a faulty process (by means of mean shift) on the cost analysis.

Citation Download Citation

Jae Yeon Claire Baek and Costas J. Spanos "Optimization of blended virtual and actual metrology schemes", Proc. SPIE 8324, Metrology, Inspection, and Process Control for Microlithography XXVI, 83241K (5 April 2012); https://doi.org/10.1117/12.916313

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available