X-ray Analysis of Disc Samples Using Total Reflection
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Solution Overview
Problem
Conventional X-ray analyzing methods struggle to accurately analyze disc-shaped samples with crystalline structures due to interference from scattered and diffracted X-rays, especially when the sample has a non-rotational symmetry, leading to inaccurate results.
Innovation Solution
An X-ray analyzing apparatus and method that includes a sample table, X-ray source, detector, parallel shifting unit, and rotating unit, controlled by a unit that positions the sample to minimize scattered and diffracted X-rays by radiating monochromated primary X-rays from above the sample and reflecting them outside the region, using a predetermined angle calculated based on the sample's radius and detector's field of view to suppress and avoid scattered and impurity X-rays, and adjust the sample's rotation to avoid diffracted X-rays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sample is rotated to avoid diffracted X-rays from crystalline structures, then measurement precision is improved, but the complexity of the measuring process increases due to additional rotation steps and angle calculations
Solution Approach 1:
The control unit pre-calculates the optimal rotation angle based on the sample radius R and detector field of view radius T using the formula sinθ1=(R−T)/R before measurement begins. This preliminary calculation eliminates the need for trial-and-error rotation during measurement, improving precision while maintaining process simplicity.
Solution Approach 2:
The patent replaces manual iterative rotation adjustment with an automated control system that calculates and executes the optimal rotation angle automatically. This substitution of mechanical trial-and-error with computational control improves measurement precision without proportionally increasing operational complexity.
2Measurement precision
If the primary X-rays are radiated from outside the region above the sample to suppress scattered X-rays, then measurement precision is improved, but the ease of operation decreases due to more complex positioning requirements
Solution Approach 1:
The control unit automatically calculates and executes the precise positioning of the primary X-ray source relative to the sample and detector, replacing manual positioning operations. This automation maintains measurement precision while significantly improving ease of operation by eliminating complex manual alignment procedures.
Solution Approach 2:
The system performs self-positioning by automatically calculating the optimal geometry based on stored sample parameters (radius R) and detector parameters (field of view radius T). The control unit autonomously determines the radiation angle and positioning without requiring operator intervention, improving both precision and ease of operation.
3Measurement precision
If the sample is positioned at a specific rotation angle to minimize scattered and diffracted X-rays, then measurement precision is improved, but the measurement time increases due to additional positioning and angle adjustment steps
Solution Approach 1:
The optimal rotation angle θ1 is pre-calculated using the formula sinθ1=(R−T)/R before the measurement begins. This preliminary determination eliminates the need for time-consuming trial-and-error adjustments during the actual measurement, improving precision without significantly increasing measurement time.
Solution Approach 2:
The automated control system rapidly calculates and executes positioning adjustments, replacing manual iterative positioning that would be time-consuming. The computer-controlled rotation and positioning mechanisms can quickly achieve the optimal angle, minimizing the time penalty while maximizing measurement precision.
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 approach effectively suppresses and avoids scattered and impurity X-rays, allowing for accurate analysis by positioning the sample at specific angles that minimize interference, thereby improving the accuracy of X-ray analysis for disc-shaped samples with crystalline structures.
Implementation Method 1
measurement is carried out by positioning the point of measurement so that the primary X-rays 2 are radiated from outside of a region above the sample S and the primary X-rays 2 so radiated may undergo a total reflection towards such region
Implementation Method 2
A portion of the primary X-rays 2 are radiated towards a vertical end face of the sample S, accompanied by emission of strong scattered X-rays 9 in all directions
Implementation Method 3
detecting secondary X-rays emanating from the sample surface and then measuring the intensity of the secondary X-rays emitted by the sample surface
Implementation Method 4
a sample of a kind having a crystalline structure, such as, for example, a wafer, when irradiated with the primary X-rays, may emit the secondary X-rays containing not only fluorescent X-rays, but also diffracted X-rays
Data Source
AI summary
An X-ray analyzing apparatus is such that a diffraction pattern, in which the intensity of secondary X-rays (4) is associated with the angle of rotation of a sample (S), is stored; while the pattern is scanned by a line of the secondary X-rays (4) intensity in a direction of highness and lowness, points on the pattern having not higher intensity than the line are taken as candidate points; respective angles of rotation of the candidate points, when the maximum value of the difference in angle of rotation between the neighboring candidate points attains a predetermined angle, are stored; depending on coordinates of a point of measurement, the angle of rotation proximate to the coordinates is read out from the stored angles; and the sample (S) is set to the read out angle and the point of measurement is arranged within the field of view (V) of a detector (7).