Methods and systems for selecting wafer locations to characterize cross-wafer variations based on high-throughput measurement signals
US12085515B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 2021 |
| Grant date | Sep 10, 2024 |
| Priority date | — |
| Expiry date | Sep 29, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods and systems for selecting measurement locations on a wafer for subsequent detailed measurements employed to characterize the entire wafer are described herein. High throughput measurements are performed at a relatively large number of measurement sites on a wafer. The measurement signals are transformed to a new mathematical basis and reduced to a significantly smaller dimension in the new basis. A set of representative measurement sites is selected based on analyzing variation of the high throughput measurement signals. In some embodiments, the spectra are subdivided into a set of different groups. The spectra are grouped together to minimize variance within each group. Furthermore, a die location is selected that is representative of the variance exhibited by the die in each group. A spectrum of a measurement site and corresponding wafer location is selected to correspond most closely to the center point of each cluster.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.