Use of 3D metrology for process control

As device structures continue to shrink and new materials are introduced, Three Dimensional (3D) Metrology becomes more important. The creation of 3D Metrology data is defined as the generation of statistically relevant 3D information used in R&D and/or semiconductor manufacturing. Parameters of interest are: profile shape, side wall angle, material properties, height of the structure, as well as the variation within a die, on the wafer, between wafers. In this paper we will show how this information is used to calibrate process control systems in a semiconductor fab. Also, results will be shown on how this information may be used to compare different types of Metrology equipment e.g. CD-SEM and optical CD metrology techniques like scatterometry. Certain applications, such as the generation of profile information for 55 nm dense contact holes in photoresist, require new technology to minimize damage to the soft photoresist. A new technique called in-situ broadband argon cleaning will be presented. Finally, the application of the argon column for protective coating deposition of sub-45 nm photoresist lines will be discussed.