Confocal Raman Inspection for Semiconductor Crystallinity Profiling
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Solution Overview
Problem
Existing semiconductor manufacturing processes, such as metal-induced lateral crystallization, face challenges in determining crystallinity without destructively testing the semiconductor substrate, leading to substrate loss and process time inefficiencies.
Innovation Solution
A semiconductor inspection device utilizing a laser beam to scan and measure Raman signals from a semiconductor substrate, with a confocal point setup to differentiate between amorphous and crystalline silicon, and calculate crystallinity based on depth, enabling non-destructive testing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a transmission electron microscope sample is used to determine crystallinity in metal-induced lateral crystallization process, then crystallinity measurement can be performed, but substrate loss and process time loss occur due to destructive testing
Solution Approach 1:
The patent replaces the mechanical/physical destructive sampling method (transmission electron microscope sample preparation) with an optical non-destructive measurement method (Raman spectroscopy). The laser beam interacts with the semiconductor substrate to generate Raman signals that provide crystallinity information without requiring physical sample destruction or extraction.
Solution Approach 2:
The patent introduces Raman scattering as an intermediary physical phenomenon to indirectly measure crystallinity. Instead of directly observing the substrate structure through destructive sampling, the system uses laser light as a mediator that interacts with the substrate and produces Raman signals that carry crystallinity information, enabling non-destructive measurement.
2Measurement precision
If a transmission electron microscope sample is used to determine crystallinity, then crystallinity measurement can be performed, but process time is lost due to destructive testing
Solution Approach 1:
The patent replaces the time-consuming destructive sampling and preparation process with an immediate optical measurement process. The Raman spectroscopy system can perform crystallinity measurements in situ and in real-time during the manufacturing process, eliminating the time required for sample preparation, analysis, and the associated process interruptions.
Solution Approach 2:
The patent enables continuous crystallinity monitoring during the metal-induced lateral crystallization process. The Raman measurement system can operate continuously without interrupting the manufacturing flow, allowing for real-time process control and eliminating the discontinuous nature of destructive sampling methods that require stopping production for analysis.
3Ease of operation
If Raman signal measurement is performed without confocal point concentration, then measurement can be conducted, but measurement precision decreases due to noise signals from non-confocal points
Solution Approach 1:
The patent applies local quality by concentrating the laser beam at a specific confocal point within the semiconductor substrate. This creates a localized measurement zone where Raman signals are generated only from the focused region, while signals from other regions are filtered out by the pinhole aperture. This spatial selectivity ensures that only relevant local information is measured, improving signal-to-noise ratio and measurement precision.
Solution Approach 2:
The patent uses the pinhole aperture as an intermediary spatial filter between the semiconductor substrate and the detector. The pinhole allows Raman signals from the confocal point to pass through while blocking noise signals from non-confocal regions, acting as a selective mediator that separates useful signals from unwanted background noise based on their spatial origin.
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 precise, non-destructive assessment of crystallinity in semiconductor substrates, improving process efficiency and reliability by providing accurate measurements of crystalline and amorphous silicon ratios and metal layer integrity.
Implementation Method 1
a laser light source configured to generate a laser beam that is scanned onto the semiconductor substrate
Implementation Method 2
the first optical system is configured to concentrate the laser beam on a confocal point
Implementation Method 3
a detector configured to measure a Raman signal from the laser beam scattered from the semiconductor substrate
Data Source
AI summary
Provided is a semiconductor inspection device. The semiconductor inspection device includes a laser light source configured to generate a laser beam that is scanned onto a semiconductor substrate, a first optical system spaced apart from a top surface of the semiconductor substrate in a vertical direction and configured to concentrate the laser beam on a confocal point, a semiconductor substrate stage arranged on one side of the semiconductor substrate and configured to move the semiconductor substrate in the vertical direction, a detector configured to measure a Raman signal from the laser beam scattered from the semiconductor substrate, and a controller configured to calculate a Raman spectrum through the Raman signal measured from the detector and pieces of peak signal data of amorphous silicon and crystalline silicon included in channel layers from the Raman spectrum and measure a degree of crystallinity based on a depth of the semiconductor substrate.