Electron Beam Pattern Measurement for Deep Etch Bottom Accuracy
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Solution Overview
Problem
As semiconductor devices become three-dimensional and patterns of grooves and holes deepen, managing the etching process to ensure accurate measurement of bottom dimensions and pattern inclination becomes increasingly challenging, affecting processing uniformity and yield.
Innovation Solution
A pattern measurement device using an electron beam calculates positional deviations between pattern surfaces and bottoms, adjusts the beam tilt angle to match pattern inclination, and measures the pattern dimensions accurately by acquiring images at specific incident angles to ensure precise feedback for the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If stereo observation with multiple images at different angles is used, then three-dimensional reconstruction accuracy improves, but the complexity of the measurement process and device increases
Solution Approach 1:
The patent extracts and utilizes only the essential angular information needed for deep pattern measurement by tilting the beam at a specific optimized angle. Instead of acquiring multiple images from various angles for full three-dimensional reconstruction, the system selectively uses a single tilted angle that provides the critical information needed for bottom dimension and inclination measurement, thereby simplifying the process.
Solution Approach 2:
The system performs preliminary calculation and determination of the optimal beam tilt angle based on the expected pattern geometry. This preliminary action allows the measurement to be conducted efficiently with a single optimized angle rather than requiring multiple angle acquisitions and complex post-processing, thus reducing device and process complexity while maintaining measurement accuracy.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for accurate measurement of bottom dimensions and inclination angles of etched patterns, improving processing accuracy and uniformity by ensuring the electron beam reaches the pattern bottom, thereby enhancing the quality of semiconductor manufacturing.
Implementation Method 1
a pattern measurement device includes a calculation device that measures a dimension of a pattern formed on a sample based on a signal obtained by a charged particle beam device
Data Source
AI summary
A computation device is provided for measuring the dimensions of patterns formed on a sample based on a signal obtained from a charged particle beam device. The computation device includes a positional deviation amount calculation unit for calculating the amount of positional deviation in a direction parallel to a wafer surface between two patterns having different heights based on an image acquired at a given beam tilt angle; a pattern inclination amount calculation unit for calculating an amount of pattern inclination from the amount of positional deviation using a predetermined relational expression for the amount of positional deviation and the amount of pattern inclination; and a beam tilt control amount calculation unit for controlling the beam tilt angle so as to match the amount of pattern inclination. The pattern measurement device sets the beam tilt angle to a calculated beam tilt angle, reacquires an image and measures the patterns.