Trench Gate Semiconductor Device Temperature-Dependent Threshold Voltage Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods fail to accurately detect potentially-defective semiconductor devices with trench gate structures during electrical characteristic inspections, as these devices may appear non-defective but deteriorate over time due to stress-induced distortion of Si—O—Si bonds, leading to interface state increases and reduced gate insulating film lifetime.
Innovation Solution
A method involving the measurement of voltage-current characteristics at different temperatures to calculate threshold voltages, with a difference between these threshold voltages determining whether a semiconductor device is non-defective or defective, allowing for the identification of potentially-defective products that would otherwise be undetectable.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional electrical characteristic inspection is performed at standard conditions, then manufacturing simplicity is maintained, but measurement precision is insufficient to detect potentially-defective products
Solution Approach 1:
The inspection method performs measurements at multiple temperatures (low temperature and high temperature) before final product determination. By conducting preliminary measurements at different temperature conditions, the method identifies potentially-defective products that would fail under stress conditions, enabling early detection before shipment.
Solution Approach 2:
The inspection method changes the temperature parameter during measurement to detect potentially-defective products. By measuring electrical characteristics at low temperature (e.g., -40°C) and high temperature (e.g., 150°C) and comparing the results, the method identifies products with abnormal temperature dependence that indicate potential defects.
2Reliability
If standard electrical characteristic inspection is used, then inspection time is reduced, but reliability of product quality is compromised
Solution Approach 1:
The method performs preliminary measurements at extreme temperatures to identify potentially-defective products before final shipment. This preliminary stress testing ensures that only products with stable electrical characteristics across temperature ranges are shipped, improving reliability.
Solution Approach 2:
The method replaces physical stress testing (applying mechanical stress to observe failure) with electrical characteristic measurement under temperature variation. By measuring how electrical parameters change with temperature, the method indirectly assesses product reliability without requiring actual stress application.
3Difficulty of detecting and measuring
If measurement is performed only at room temperature, then manufacturing precision requirements are simplified, but detection capability for temperature-dependent defects is lost
Solution Approach 1:
The method changes the temperature parameter during measurement to access the microcurrent region characteristics that are not visible at room temperature. By measuring at low temperature where thermal noise is reduced, the method can detect subtle defects in the microcurrent region that indicate potential future failures.
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 enables the accurate differentiation between non-defective and potentially-defective semiconductor devices, preventing the shipment of defective products by identifying devices with small temperature-dependent microcurrent region characteristics.
Implementation Method 1
measuring a first voltage-current characteristic indicating a relation between a main current and a gate voltage under a first temperature; calculating a first threshold voltage based on the first voltage-current characteristic... measuring a second voltage-current characteristic indicating a relation between the main current and the gate voltage under a second temperature different from the first temperature
Data Source
AI summary
A method for manufacturing a semiconductor device having a trench gate structure is provided. In the method, a first voltage-current characteristic indicating a relation between the main current and the gate voltage under a first temperature is measured to calculate a first threshold voltage. A second voltage-current characteristic indicating a relation between the main current and the gate voltage under a second temperature different from the first temperature is measured to calculate a second threshold voltage. It is determined whether the semiconductor device is a non-defective product or a defective product based on whether a difference between the second threshold voltage and the first threshold voltage is larger than a determination threshold value.