Multi-Spot Optical Probe Array for Wafer Film Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current film thickness measurement systems in semiconductor manufacturing are inefficient due to their reliance on single-spot measurements, which are costly and time-consuming, especially when measuring across the entire wafer, and are not suitable for simultaneous front and backside surface analysis without causing surface defects or contamination.
Innovation Solution
A multi-spot analysis system with multiple optical probes that uses a plurality of transmitting and receiving optical fibers optically coupled to an illumination source and detector, respectively, along with switches to efficiently illuminate and measure multiple points on a sample surface without actuating the sample, allowing for simultaneous front and backside surface analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If single-spot measurement systems are used, then measurement precision is maintained, but measurement time increases and productivity decreases
Solution Approach 1:
The patent divides the measurement system into multiple independent optical probes, each capable of measuring a specific spot on the wafer. Instead of using a single probe that scans across the wafer surface, multiple probes are arranged in arrays to simultaneously measure multiple locations, thereby increasing throughput while maintaining measurement precision at each spot.
Solution Approach 2:
The patent transitions from a single-dimensional scanning approach to a multi-dimensional parallel measurement approach. By arranging optical probes in two-dimensional arrays and using optical fiber bundles to deliver illumination and collect signals from multiple spots simultaneously, the system achieves parallel measurement across the wafer surface without requiring mechanical scanning.
2Area of stationary object
If mechanical scanning is used to measure multiple points, then full-wafer coverage is achieved, but system complexity and cost increase
Solution Approach 1:
The patent combines multiple optical measurement functions into a single integrated system. Multiple optical probes, illumination sources, and detectors are merged into one system that can simultaneously measure multiple spots across the wafer. The optical fiber bundles merge multiple light paths into unified illumination and collection channels, reducing the need for separate scanning mechanisms and control systems.
Solution Approach 2:
The patent replaces mechanical scanning systems with an optical-based parallel measurement system. Instead of using motors, stages, and precision positioning mechanisms to scan a single probe across the wafer, the system uses stationary optical probe arrays with optical fibers to deliver light and collect signals from multiple locations simultaneously, eliminating complex mechanical components.
3Productivity
If multiple optical probes are used, then measurement time is reduced and productivity increases, but device complexity increases
Solution Approach 1:
The patent designs optical probes that perform multiple functions simultaneously. Each optical probe can both illuminate the sample and collect reflected or transmitted light for measurement. The optical fiber bundles serve dual purposes of delivering illumination and collecting signals. This multi-functionality reduces the need for separate illumination and detection systems for each measurement spot, thereby increasing throughput without proportionally increasing system complexity.
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
Enables fast and accurate film thickness measurement across the entire wafer, reducing measurement time and cost, while avoiding surface defects and contamination, and providing high spatial resolution and throughput.
Implementation Method 1
an illumination source with a plurality of transmitting optical fibers optically coupled to the illumination source and a detector with a plurality of receiving optical fibers optically coupled to the detector
Implementation Method 2
receive illumination reflected, refracted, or radiated from the respective portions of the surface of the sample
Implementation Method 3
receive illumination reflected, refracted, or radiated from the respective portions of the surface of the sample
Data Source
AI summary
A system for analyzing a sample includes an illumination source with a plurality of transmitting optical fibers optically coupled to the illumination source and a detector with a plurality of receiving optical fibers optically coupled to the detector. The system further includes a plurality of probes coupled to respective ones of the plurality of transmitting optical fibers and respective ones of the plurality of receiving optical fibers. The plurality of probes are configured to illuminate respective portions of a surface of the sample and configured to receive illumination reflected, refracted, or radiated from the respective portions of the surface of the sample. The system may further include one or more switches and/or splitters configured to optically couple respective ones of the plurality of transmitting optical fibers to the illumination source and/or configured to optically couple respective ones of the plurality of receiving optical fibers to the detector.