Polarized Light Probing for Sub-32nm IC Feature Detection
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Solution Overview
Problem
The rapid miniaturization of integrated circuits poses a challenge for debugging and analytical tools to discern and analyze ultra-fine circuit features in ICs fabricated by 22 nm or smaller CMOS technologies, leading to increased manufacturing costs and decreased yield.
Innovation Solution
A novel microscopy method using an optical focus system with linearly polarized light to detect and image ultra-fine features on semiconductor substrates, employing a solid immersion lens and polarization manipulation to enhance signal detection and resolution, allowing for the identification of features not visible with conventional techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional optical microscopy is used to probe circuit features, then the equipment is simple and easy to operate, but the resolution is insufficient to detect sub-32 nm features
Solution Approach 1:
The patent changes the polarization parameter of incident light from unpolarized to linearly polarized, and introduces polarization angle modulation to enhance the contrast and resolution of sub-32 nm circuit features. This parameter change enables detection of features that are invisible to conventional optical microscopy without requiring complex super-resolution equipment.
Solution Approach 2:
The patent employs periodic modulation of the polarization angle of incident light to selectively highlight different circuit features. By varying the polarization angle periodically and detecting the reflected light at specific angles, the system achieves enhanced resolution for sub-32 nm features through periodic action rather than requiring a completely different optical system.
2Productivity
If circuit features are shrunk to sub-32 nm size to improve device functionality, then device performance and integration are improved, but manufacturing precision requirements increase and yield decreases
Solution Approach 1:
The patent replaces conventional optical microscopy with a polarization-based optical detection system that uses the polarization properties of light to achieve higher resolution. This substitution of the detection mechanism enables verification of sub-32 nm features without requiring mechanical or optical systems of comparable complexity, thereby supporting manufacturing precision improvements.
3Reliability
If conventional probing tools are used for debugging, then the tools are simple and cost-effective, but they cannot detect modulated signals in sub-volt devices
Solution Approach 1:
The patent changes the detection parameter from intensity-only detection to polarization-state-dependent detection. By measuring the polarization state of reflected light and modulating the incident polarization angle, the system can detect modulated signals in sub-volt devices that are invisible to conventional probing tools, achieving enhanced reliability without requiring complex electronic probing systems.
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 method enables the detection of ultra-fine features with enhanced resolution and signal strength, improving the ability to probe and analyze sub-32 nm integrated circuits, thereby addressing the limitations of existing tools in debugging and manufacturing.
Implementation Method 1
focusing a first incident light by the optical focus system to produce a first focused light spot on a portion of the integrated circuit
Implementation Method 2
the first incident light is linearly polarized in a first linear polarization substantially parallel to the circuit horizontal direction
Implementation Method 3
detecting, by a photo detector, a first reflected light reflected from the portion of the integrated circuit
Implementation Method 4
producing, by a scanning system, a relative movement between the first focused light spot and the integrated circuit to allow the first focused light to illuminate different portions of the integrated circuit
Data Source
AI summary
A method for detecting ultra-fine features of an integrated circuit (IC) on a semiconductor substrate is disclosed. The semiconductor substrate comprises an IC fabricated by 22 nanometer or smaller scale semiconductor micro-fabrication process. The integrated circuit includes circuit features parallel to a circuit horizontal direction or a circuit vertical direction. The method includes focusing an incident light to produce a focused light spot on a portion of the IC. The incident light is linearly polarized in a linear polarization substantially parallel to the circuit horizontal direction. The method includes detecting reflected light from the portion of the IC, producing a relative movement between the focused light spot and the IC to allow the focused light to illuminate different portions of the IC, obtaining an image of the IC using signals of the reflected light detected from different locations of the integrated circuit, and detecting IC features in the image.