Lithography process optimization for 130-nm polygate mask and the impact of mask error factor

This paper describes the design and implementation of a system for monitoring the performance of several major subsystems of a critical dimension measurement scanning electron microscope (CD-SEM). Experiments were performed for tests involving diagnosis of the vacuum system and column stability by monitoring of the following subsystems and associated functional parameters. These include: 1) Vacuum system with pressure as a function of time being recorded for the electron-optical column (gun chamber), the specimen chamber, and the sample-loading unit. 2) The action of several components of the wafer handling system can be timed. 3) The electron gun emission currents and other signals to monitor the characteristics of the condenser and objective lenses may be used to correlate with image quality. 4) Image sharpness, electron beam current, signal-to-noise ratio, etc. can be evaluated.