Method for obtaining the dielectric constant of a dielectric sheet
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Solution Overview
Problem
Scanning capacitance microscopy is unable to accurately measure the dielectric constant of dielectric sheets due to measurement errors caused by shape variations and internal voids in the samples.
Innovation Solution
A method using a semiconductor capacitor and three parallel plate capacitors connected in series, with known dielectric constants and thicknesses, to calculate the dielectric constant of a dielectric sheet by measuring scanning capacitance microscopy signals and impedance ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the dielectric resonance method is used to measure the dielectric constant, then the measurement can be performed, but measurement errors are introduced due to shape variations and internal voids in the sample
Solution Approach 1:
The patent introduces an intermediary approach by using a reference dielectric sheet with known properties and a semiconductor capacitor with depletion region as a mediator between the measurement system and the test dielectric sheet. The semiconductor capacitor's depletion region acts as a sensitive probe that interacts with the dielectric sheet without requiring direct contact or precise geometric matching, thereby eliminating the harmful effects of shape variations and internal voids on measurement accuracy.
Solution Approach 2:
The patent replaces the traditional mechanical resonance-based measurement system with an electrical field-based scanning capacitance microscopy system. Instead of relying on mechanical resonance frequency measurements that are sensitive to geometric variations, the system uses electrical field interactions and capacitance measurements to determine the dielectric constant, substituting mechanical measurement principles with electrical measurement principles to eliminate geometric sensitivity.
2Measurement precision
If scanning capacitance microscopy is used to measure dielectric constant, then measurement errors from shape variations can be reduced, but the method cannot accurately measure dielectric sheets with internal voids
Solution Approach 1:
The patent applies parameter changes by utilizing the voltage-dependent capacitance characteristics of the semiconductor capacitor's depletion region. By applying different modulation voltages and measuring the resulting capacitance changes, the system can distinguish between the dielectric constant and the presence of internal voids. The depletion region's capacitance is sensitive to both dielectric properties and structural defects, allowing simultaneous measurement of dielectric constant and detection of internal voids through parameter analysis.
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 reduces measurement errors by accounting for shape variations and internal voids, extending scanning capacitance microscopy to accurately measure dielectric constants of dielectric sheets.
Implementation Method 1
connecting a semiconductor capacitor and a first parallel plate capacitor in series... measuring a first scanning capacitance microscopy signal corresponding to the semiconductor capacitor and the first parallel plate capacitor
Implementation Method 2
calculating an impedance ratio based on the first scanning capacitance microscopy signal, the second scanning capacitance microscopy signal, and (d2/d1)×(ε1/ε2)... obtaining a third dielectric constant of the third dielectric sheet
Implementation Method 3
applying a modulation voltage to the semiconductor capacitor and the first parallel plate capacitor to periodically change a width of the depletion region
Implementation Method 4
applying a modulation voltage to the semiconductor capacitor and the first parallel plate capacitor to periodically change a width of the depletion region
Data Source
AI summary
In a method for obtaining the dielectric constant of a dielectric sheet, a modulation voltage is applied to a semiconductor capacitor and a first parallel plate capacitor to measure a first scanning capacitance microscopy signal. Then, the first parallel plate capacitor is replaced with a second parallel plate capacitor to measure a second scanning capacitance microscopy signal corresponding to the semiconductor capacitor and the second parallel plate capacitor. Finally, the second parallel plate capacitor is replaced with a third parallel plate capacitor to measure a third scanning capacitance microscopy signal corresponding to the semiconductor capacitor and the third parallel plate capacitor. Based on the scanning capacitance microscopy signals and dielectric constants and the equivalent physical thicknesses of the dielectric sheets of the first parallel plate capacitor and second parallel plate capacitor, the dielectric constant of the dielectric sheet of the third parallel plate capacitor is obtained.