Process control using three dimensional reconstruction metrology
US6651226B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2001 |
| Grant date | Nov 18, 2003 |
| Priority date | — |
| Expiry date | Dec 5, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70625
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In-line process control for 120 nm and 100 nm lithography using the installed scanning electron microscope (SEM) equipment base. A virtual three-dimensional representation of a photoresist feature is developed by applying a transform function to SEM intensity data representing the feature. The transform function correlates highly accurate height vector data, such as provided by a stylus nanoprofilometer or scatterometer, with the highly precise intensity data from the SEM. A multiple parameter characterization of at least one critical dimension of the virtual feature is compared to an acceptance pattern template, with the results being used to control a downstream etch process or an upstream lithography process. A multiple parameter characteristic of a three dimensional representation of the resulting post-etch final feature may be compared to device performance data to further refine the acceptance pattern template.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.