CMP Offset Correction Using Layout-Trained Measurement Models
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Solution Overview
Problem
In semiconductor device manufacturing, the CMP process requires reliable measurement of micropatterns, but existing optical methods for large-area offset measurement are inefficient and require additional processes, such as forming a metal film, which increases turnaround time.
Innovation Solution
An offset data correction method that involves measuring a semiconductor device post-CMP, generating an offset correction model using measured and layout data, and applying this model to correct measured data, thereby improving measurement reliability without the need for additional processes like forming a metal film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an additional process of forming a metal film is performed to check large-area offset by optical method, then measurement capability is improved, but turnaround time increases and process complexity increases
Solution Approach 1:
The patent extracts and removes the unnecessary metal film formation process from the measurement workflow. By using optical metrology to directly measure the semiconductor device structure without requiring metal film deposition, the method eliminates this redundant step while maintaining measurement capability through direct optical inspection of the device geometry
Solution Approach 2:
The patent makes the optical measurement system universal by enabling it to perform both small-area and large-area offset measurements without requiring different preparation methods. The same optical metrology tool can measure various structures (contact holes, trenches, vias) directly on the semiconductor device, eliminating the need for metal film formation that was previously required for certain measurement types
2Measurement precision
If an additional process of forming a metal film is performed to check large-area offset by optical method, then measurement capability is improved, but process complexity increases
Solution Approach 1:
The patent extracts and removes the unnecessary metal film formation process from the measurement workflow. By using optical metrology to directly measure the semiconductor device structure without requiring metal film deposition, the method eliminates this redundant step while maintaining measurement capability through direct optical inspection of the device geometry
Solution Approach 2:
The patent enables the semiconductor device structure itself to serve as the measurement target without requiring additional metal film layers. The device's own geometric features (contact holes, trenches, vias) are used as reference structures for optical measurement, making the device self-sufficient for measurement purposes and eliminating external process dependencies
3Ease of operation
If conventional optical measurement method is used without correction model, then measurement process is simple, but measurement precision deteriorates due to offset errors
Solution Approach 1:
The patent implements a feedback mechanism where an offset correction model is trained using measured data and layout data, then applied to correct subsequent measurements. The system continuously learns from measurement results and adjusts offset corrections accordingly, improving measurement accuracy while maintaining operational simplicity through automated correction algorithms
Solution Approach 2:
The patent performs preliminary training of the offset correction model using measured data and layout data before actual measurements. By pre-establishing the correction relationships between measured positions and actual positions based on device layout information, the system prepares correction parameters in advance that can be quickly applied during measurement without adding operational complexity
Data Source
AI summary
An offset data correction method includes measuring a measurement target that has undergone a chemical mechanical polishing (CMP) process, generating an offset correction model based on the measurement of the measurement target, and using the offset correction model, correcting measured data obtained from the measurement of the measurement target, wherein the offset correction model is trained by using the measured data and layout data of the measurement target as inputs.