Semiconductor Patterning Feedback Control for Line Width Precision
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Solution Overview
Problem
When performing multiple patterning steps on a semiconductor device wafer, variations in line width occur due to separate exposure and developing treatments, making it difficult to achieve a desired pattern dimension, which is crucial for miniaturizing semiconductor devices to fine line widths like 32 nm or 45 nm.
Innovation Solution
A substrate processing method that involves measuring the pattern dimension after the first patterning step and adjusting subsequent patterning conditions based on this measurement to maintain consistent line width, allowing for precise control of exposure, heating, and developing treatments to achieve the target dimension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple patterning steps are performed separately with independent exposure and developing treatments, then the patterning process can be completed, but line width variations occur between steps making it difficult to achieve desired pattern dimension
Solution Approach 1:
The patent applies feedback by measuring the line width after the first patterning step and using this measurement to adjust the exposure conditions for subsequent patterning steps. This closed-loop control ensures that line width variations are compensated, maintaining consistent pattern dimensions across multiple patterning operations.
Solution Approach 2:
The patent changes the exposure parameters (such as exposure amount or wavelength) based on the measured line width from previous patterning steps. By dynamically adjusting these parameters, the system compensates for variations and achieves uniform line width across all patterning steps, resolving the contradiction between completing multiple patterning operations and maintaining precision.
2Adaptability or versatility
If exposure processing and developing treatment are performed separately for each patterning, then each patterning can be independently controlled, but specific variations in line width occur in each patterning
Solution Approach 1:
The system maintains independent control of each patterning step while introducing feedback from previous steps. The line width measurement from each completed patterning step feeds into the parameter adjustment for the next step, allowing independent control to be preserved while eliminating line width variations through continuous optimization.
Solution Approach 2:
The patent replaces purely mechanical/independent process execution with a system that uses measurement and calculation to determine subsequent process parameters. Instead of treating each patterning step as completely independent, the system substitutes a computational approach that uses measured data to calculate optimal parameters for the next step, thereby ensuring uniformity.
3Ease of manufacture
If only wavelength shortening is used for exposure processing, then the method is simple, but it is technically difficult to form semiconductor devices at fine line width levels of 32 nm or 45 nm
Solution Approach 1:
The patent goes beyond simple wavelength shortening by dynamically changing multiple exposure parameters (exposure amount, wavelength, or other conditions) based on measured line width data. This multi-parameter adjustment approach enables the formation of fine line width patterns at 32 nm or 45 nm levels while maintaining a relatively simple overall process framework.
Solution Approach 2:
The patent performs preliminary measurements of line width after each patterning step before proceeding to the next step. This preliminary action of measurement and parameter calculation enables the system to prepare the optimal exposure conditions in advance for subsequent patterning, ensuring fine line width capability is achieved through proactive parameter optimization rather than reactive correction.
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 ensures that the pattern dimensions remain consistent across multiple patterning steps, enabling the formation of a desired fine pattern on the semiconductor device, advancing the miniaturization of semiconductor devices by maintaining precise control over the patterning process.
Implementation Method 1
heating processing of heating the wafer to accelerate the chemical reaction in the exposed resist film (post-exposure baking)
Data Source
AI summary
In the present invention, patterning for the first time is performed on a film to be worked above the front surface of a substrate, and the actual dimension of the pattern formed by the patterning for the first time is measured. Based on the dimension measurement result of the patterning or the first time, the condition of patterning for the second time is then set. In this event, the condition of the patterning for the second time is set so that a difference between the dimension of the patterning for the first time and its target dimension is equal to a difference between the dimension of the patterning for the second time and its target dimension. Thereafter, the patterning for the second time is performed under the set patterning condition.