Apparatus and method for aligning a wafer's backside to a wafer's frontside
US8947664B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 2009 |
| Grant date | Feb 3, 2015 |
| Priority date | — |
| Expiry date | Mar 27, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J5/0007
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Structures of a backside of a wafer can be aligned to structures of a frontside of the wafer for a lithographic treatment of the backside. The wafer is transparent for electromagnetic radiation of a specific wavelength. The wafer is placed on a wafer stage such that the frontside is facing the wafer stage and the backside is facing alignment optics. The backside is illuminated with electromagnetic radiation of the specific wavelength in a dark-field configuration, such that the electromagnetic radiation propagates through the wafer towards three-dimensional structures of a three-dimensional alignment target located at the frontside or inside the wafer and is scattered at the three-dimensional structures. The scattered electromagnetic radiation is captured with the alignment optics, and the backside is aligned to the frontside of the wafer based on the scattered electromagnetic radiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.