Optical Phased Array Metrology for Fast Defect Localization
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Solution Overview
Problem
Current metrology systems struggle to keep pace with the increasing complexity and density of integrated circuits, requiring improved capabilities for rapid and accurate measurement of lithographic features.
Innovation Solution
A metrology system incorporating a phased array with optical elements, waveguides, and phase modulators to generate and direct radiation beams for defect detection, along with a detector and comparator to analyze scattered radiation for precise defect localization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional scatterometer systems are used to measure lithographic features, then measurement accuracy can be maintained, but measurement speed and productivity are insufficient for high-volume manufacturing rates
Solution Approach 1:
The patent divides the measurement task into multiple parallel measurement beams that simultaneously inspect different features on the substrate. Instead of sequentially measuring one feature at a time, the system uses segmented illumination with multiple beams to achieve parallel processing, thereby increasing productivity while maintaining measurement precision through dedicated detection for each beam
Solution Approach 2:
The patent transitions from conventional single-beam or limited multi-beam systems to a phased array configuration that enables two-dimensional parallel measurement across the substrate surface. This dimensional expansion allows simultaneous measurement of multiple features in both x and y directions, dramatically improving measurement speed without sacrificing accuracy
2Productivity
If the number of simultaneous measurements is increased to improve productivity, then measurement speed increases, but system complexity increases
Solution Approach 1:
The patent employs a phased array system where a single multi-functional device performs multiple measurement tasks simultaneously. The phased array can dynamically configure beam patterns, adjust illumination angles, and target different feature types using the same hardware infrastructure, reducing overall system complexity compared to having separate measurement systems for each function
Solution Approach 2:
The patent uses dynamically controllable phase modulators that can real-time adjust beam characteristics, directions, and focal points. This dynamic control allows the system to adapt measurement parameters on-the-fly without physical reconfiguration, enabling high productivity while keeping the physical system relatively simple through software-controlled flexibility
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
Enhances the speed and accuracy of defect detection on substrates, enabling faster and more reliable measurement of critical dimensions and overlay errors in advanced lithographic processes.
Implementation Method 1
phase modulators configured to adjust phases of the radiation waves such that the radiation waves combine to form the beam
Implementation Method 2
radiation waves combine to form the beam
Implementation Method 3
detector configured to receive radiation scattered from the surface
Data Source
AI summary
A metrology system includes a radiation source (708), a phased array (722a,b;724a,b;726;734), a detector, and a comparator. The phased array includes optical elements (706), waveguides (704), and phase modulators (702). The phased array generates a beam of radiation and directs the beam toward a surface of an object. The optical elements radiate radiation waves. The waveguides guide radiation from the radiation source to the optical elements. The phase modulators adjust phases of the radiation waves such that the radiation waves combine to form the beam. The detector receives radiation scattered from the surface and generates a detection signal based on the received radiation. The comparator analyzes the detection signal and determines a location of a defect on the surface based on the analyzing.