Semiconductor Stack Inspection Using Multi-Frequency Phase Normalization
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Solution Overview
Problem
Conventional methods struggle to analyze the electrical characteristics of semiconductor devices with stacked semiconductor chips, particularly in a non-destructive manner.
Innovation Solution
A semiconductor device inspection method and device that utilize light intensity-modulated with multiple frequencies to acquire and process characteristic signals, correcting and normalizing phase components to estimate the layer structure and analyze the stacked structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional single-frequency OBIRCH method is used, then the measurement process is simple, but it cannot analyze electrical characteristics corresponding to stacked structure of semiconductor devices
Solution Approach 1:
The patent segments the measurement process by using multiple frequency components (first frequency and second frequency) to probe different depths of the stacked semiconductor structure. Each frequency component provides information about specific layers, enabling depth-resolved electrical characteristic analysis without physical sectioning
Solution Approach 2:
The patent employs periodic light intensity modulation at different frequencies to stimulate and detect electrical characteristics at various depths. The periodic modulation allows lock-in detection to extract phase information that corresponds to different stacking positions, transforming a complex three-dimensional analysis problem into manageable periodic signal measurements
2Measurement precision
If multiple frequency components are used to analyze stacked structure, then electrical characteristics of each layer can be analyzed, but phase component mixing occurs reducing measurement accuracy
Solution Approach 1:
The patent extracts specific phase components corresponding to different frequency modulations from the composite signal. By using lock-in detection tuned to each modulation frequency, the system separates and extracts the phase information associated with each depth layer, removing the mixing effect and enabling independent analysis of each stack layer's electrical characteristics
Solution Approach 2:
The patent uses phase component normalization as an intermediary process to eliminate the mixing effect. By normalizing the phase components with respect to a reference, the system removes the influence of other layers' signals, allowing accurate extraction of depth-specific electrical characteristics from the composite measurement signal
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 accurate analysis of electrical characteristics corresponding to the stacked structure of semiconductor devices, improving estimation accuracy through phase component correction and normalization.
Implementation Method 1
Lock-in Optical Beam Induced Resistance Change (OBIRCH) has been known as a method for analyzing the electrical characteristics of a semiconductor device in which semiconductor chips are stacked in a three-dimensional manner
Implementation Method 2
failure analysis of a semiconductor device is realized in a non-destructive manner by measuring changes in electrical characteristics, such as resistance, while scanning the semiconductor device with a laser
Data Source
AI summary
A semiconductor inspection device includes: a measuring device that supplies power to a semiconductor device and measures the electrical characteristics of the semiconductor device; an optical scanning device that scans the semiconductor device with light intensity-modulated with a plurality of frequencies; a lock-in amplifier that acquires a characteristic signal indicating the electrical characteristics of the plurality of frequency components; and an inspection device that corrects a phase component of the characteristic signal at an arbitrary scanning position with a phase component at a scanning position reflecting the electrical characteristics of a first layer in the semiconductor device as a reference, specifies a phase component of the characteristic signal at a scanning position reflecting the electrical characteristics of a second layer, normalizes the phase component of the characteristic signal at the arbitrary scanning position by using the phase component, and outputs a result based on the normalized phase component.