Systems and methods for measuring stress in a specimen are provided. One
system includes an optical subsystem configured to measure stress-induced
birefringence in patterned structures formed on the specimen. In some
embodiments, the optical subsystem may be configured as a spectroscopic
ellipsometer, a multi-angle laser ellipsometer, a polarimeter, a
polarized reflectometer, or some combination thereof. The system also
includes a processor coupled to the optical subsystem. The processor is
configured to determine stress in a material of the patterned structures
using the stress-induced birefringence measurements. One method includes
measuring stress-induced birefringence in patterned structures formed on
the specimen using an optical technique. The method also includes
determining stress in a material of the patterned structures using the
stress-induced birefringence measurements.