Methods and systems for improved localized feature quantification in surface metrology tools
US8630479B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 2011 |
| Grant date | Jan 14, 2014 |
| Priority date | — |
| Expiry date | Jan 30, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30148
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for enabling more accurate measurements of localized features on wafers is disclosed. The method includes: a) performing high order surface fitting to more effectively remove the low frequency shape components and also to reduce possible signal attenuations commonly observed from SEMI standard high pass, such as Gaussian and Double Gaussian filtering; b) constructing and applying a proper two dimensional LFM window to the residual image from the surface fitting processing stage to effectively reduce the residual artifacts at the region boundaries; c) calculating the metrics of the region using the artifact-reduced image to obtain more accurate and reliable measurements; and d) using site-based metrics obtained from front and back surface data to quantify the features of interest. Additional steps may also include: filtering data from measurements of localized features on wafers and adjusting the filtering behavior according to the statistics of extreme data samples.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.