Nonuniform Optical Losses in Laser SEE Tests

Lasers can be used in combination with ions for SEE testing. The most practical technique of such tests is based on the comparison between the SEE cross-section vs. ion LET and the SEE cross-section vs. laser pulse energy. However there can be a significant error in the latter curve since the effective laser energy is not the same over different locations on the chip due to the IC´s metallization nonuniformity. This nonuniformity can be taken into account through the optical beam induced current (OBIC) examination which is considered in this article.