Spectral reflectometry for in-situ process monitoring and control
US10438825B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 2017 |
| Grant date | Oct 8, 2019 |
| Priority date | — |
| Expiry date | Aug 28, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods and systems for performing in-situ, selective spectral reflectometry (SSR) measurements of semiconductor structures disposed on a wafer are presented herein. Illumination light reflected from a wafer surface is spatially imaged. Signals from selected regions of the image are collected and spectrally analyzed, while other portions of the image are discarded. In some embodiments, a SSR includes a dynamic mirror array (DMA) disposed in the optical path at or near a field plane conjugate to the surface of the semiconductor wafer under measurement. The DMA selectively blocks the undesired portion of wafer image. In other embodiments, a SSR includes a hyperspectral imaging system including a plurality of spectrometers each configured to collect light from a spatially distinct area of a field image conjugate to the wafer surface. Selected spectral signals associated with desired regions of the wafer image are selected for analysis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.