COMBINED OPTICAL OVERLAY/CD TARGET ARRAY
Original Publication Date: 2004-Aug-30
Included in the Prior Art Database: 2004-Aug-30
National Institute of Standards and Technology
This is a write up to describe a new invention which consists of a method and target design for overlay and critical dimension mesurements using optical methods. The key is two fold. One aspect is to allow optical overlay measurements using device sized dimensions and the other aspect is to enable critcal dimention measurement, but using the same target. The targets are unique for overlay alone, but provide a particularly interesting application when combined with CD measurements.