Applied Materials, Inc.

Shirley Hemar

Yair Eran

Ami Sade

Gad Greenberg

Boaz Kenan

Gadi Greenberg

Mula Friedman

Alex Goldenshtein

A method and apparatus for inspecting a reticle measures line widths using an inspection tool that images the reticle and compares the image with a design database to detect errors in real time. The differences between the line widths of patterns on the reticle and the design database are stored during the inspection procedure. The difference (or 'bias') information is then processed off-line to create a map of all the local line-width deviation values (i.e., bias) of every feature on the reticle. The resultant local bias map can be used as a feedback mechanism to improve the reticle manufacturing process, as a 'go/no go' criteria for the validity of the reticle, and as a standard report shipped together with the mask to the wafer fabrication facility, where it can be used as a yield-enhancing tool.

Local bias map using line width measurements

A reticle inspection system and method for complete and fast inspection of phase shift mask reticles, both for incoming inspection and for periodic and pre-exposure inspection tool, is employable by facilities such as mask shops as an inspection tool compatible to the mask shop's customers. The inventive system and method detect phase errors in an aerial image by acquiring the image of the phase shift mask under the same optical conditions as the exposure conditions (i.e. wavelength, numerical aperture, sigma, and illumination aperture type). Images are acquired at a positive out-of-focus and a negative out-of-focus, and are compared in order to enhance possible phase error. The term 'phase error' refers to the acceptable range of the phase deviation from the programmed 180&#xb0; on the phase shift mask, by using the exposure system to achieve the image on the photoresist, satisfying the requirements of the wafer specification.

Alternating phase-shift mask inspection method and apparatus

Growing community of inventors

Tel Aviv, Israel

Shirley Hemar