Monitor Electrode Layout for Accurate Forward Voltage Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor wafers face challenges in accurately measuring forward voltage drop due to restricted current flow during measurement, leading to degraded accuracy, and potential discharge issues between electrodes, which affect the uniformity and performance of connected devices.
Innovation Solution
The semiconductor apparatus includes a design with specific distance settings between electrodes and insulating film coverage to prevent discharge by ensuring the discharge voltage exceeds the avalanche breakdown voltage, using depletion prevention regions and trenches to control the depletion layer expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the distance between the channel stopper electrode and the monitor electrode is reduced to improve measurement precision, then measurement precision is improved, but discharge occurs between the electrodes
Solution Approach 1:
An insulating film is introduced as an intermediary between the channel stopper electrode and the monitor electrode. This insulating film covers the inner edge portion of the monitor electrode and the outer edge portion of the channel stopper electrode, preventing direct discharge between the electrodes while allowing the edges to be positioned close together for improved measurement precision.
Solution Approach 2:
The solution moves from a two-dimensional planar separation to a three-dimensional structure by adding the insulating film dimension. The insulating film provides vertical separation between electrodes while allowing horizontal proximity, effectively using the third dimension to resolve the contradiction between close spacing and discharge prevention.
2Stability of the object's composition
If forward voltage drop is measured with relatively low current to improve device uniformity, then device uniformity is improved, but measurement accuracy degrades
Solution Approach 1:
The patent replaces direct electrical measurement at high current with an indirect measurement method using low current through the monitor electrode. The monitor electrode measures forward voltage drop at low current, and this measurement is used to predict the high-current characteristics, substituting direct high-current measurement with a low-current indirect measurement system.
Solution Approach 2:
The monitor electrode creates a simplified copy or model of the actual device structure, allowing measurement of forward voltage drop characteristics without requiring the full current load. The monitor electrode's measurement at low current serves as a proxy for predicting high-current performance, enabling uniformity assessment without degraded accuracy.
3Measurement precision
If the edges of the monitor electrode and channel stopper electrode are positioned close together to improve measurement precision, then measurement precision is improved, but the risk of discharge increases
Solution Approach 1:
The insulating film serves as a mediator between the closely positioned electrode edges. It physically separates the conductive paths while allowing the edges to remain close for precise measurement. The insulating film material and thickness are designed to withstand the operating voltage while maintaining compact electrode spacing.
Solution Approach 2:
The insulating film is positioned in advance between the electrode edges to prevent discharge before it can occur. This protective layer acts as a pre-established barrier that cushions against the harmful discharge effect, allowing the electrodes to be positioned closer than would otherwise be safe.
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 design achieves favorable measurement accuracy of forward voltage drop characteristics with low current and prevents discharge, enabling uniform performance across connected devices.
Implementation Method 1
a distance between the outer edge portion of the channel stopper electrode and the inner edge portion of the monitor electrode is a first distance, a distance between the diffusion layer and the first depletion prevention region is a second distance, and the first and second distances are set so that a discharge voltage between the channel stopper electrode and the monitor electrode becomes greater than an avalanche breakdown voltage at a PN junction portion of the diffusion layer and the semiconductor substrate
Data Source
AI summary
A semiconductor apparatus includes: a semiconductor substrate; a diffusion layer; a first depletion prevention region; a channel stopper electrode, a monitor electrode and an insulating film. The inner edge portion of the monitor electrode is positioned between the diffusion layer and the first depletion prevention region. A distance between the outer edge portion of the channel stopper electrode and the inner edge portion of the monitor electrode is a first distance. A distance between the diffusion layer and the first depletion prevention region is a second distance. The first and second distances are set so that a discharge voltage between the channel stopper electrode and the monitor electrode becomes greater than an avalanche breakdown voltage at a PN junction portion of the diffusion layer and the semiconductor substrate.