EPE contribution analysis method of multiple patterning lithography by Monte Carlo and Sobol sensitivity analysis

Area of Science:

• Semiconductor Manufacturing
• Process Engineering
• Lithography and Etching

Background:

• Shrinking critical dimensions in semiconductor technologies necessitate tighter process margins.
• Multiple patterning schemes amplify the importance of edge placement error (EPE) analysis for process performance and yield.
• Accurate EPE assessment is vital for maintaining in-line process control.

Purpose of the Study:

• To propose a novel EPE contribution analysis method for multiple litho-etch (LE) patterning processes.
• To simulate and quantify the impact of individual process steps on the after-etch-inspection (AEI) contour.
• To identify critical process parameters influencing AEI critical dimensions (CDs) and spaces.

Main Methods:

• Development of a process flow model for quadruple patterning.
• Simulation of resist profiles under varying process conditions.
• Statistical analysis using Monte Carlo and Sobol sensitivity analysis for AEI contour distribution.
• Quantification of parameter contributions to AEI CDs and spaces.

Main Results:

• The after-develop-inspection (ADI) contour significantly impacts EPE.
• Deposition and etching process parameters show comparable contributions to EPE.
• Overlay errors primarily affect the distribution of spaces.
• Sobol sensitivity analysis identified key contributors to EPE.

Conclusions:

• The proposed method effectively analyzes EPE contributions in quadruple patterning.
• Understanding parameter impacts guides process optimization for improved yield.
• Error budgets for individual parameters can be derived to meet EPE specifications.