Semiconductor Threshold Voltage Screening After Plating Anneal
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Solution Overview
Problem
Existing semiconductor device fabrication methods struggle with variations in threshold voltage due to sodium ions, which can be influenced by high-temperature environments, leading to defective devices and increased manufacturing costs.
Innovation Solution
A fabrication method involving an annealing process that diffuses sodium ions within the interlayer insulating film to a significant extent, followed by a voltage applying process that incorporates a specific electric field to screen out defective devices, ensuring consistent threshold voltage and reducing defective semiconductor packages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a plating process is performed on the electrode surface, then the electrical conductivity and corrosion resistance are improved, but sodium ions from the plating solution may be incorporated into the semiconductor substrate causing threshold voltage variations
Solution Approach 1:
The patent converts the harmful effect of sodium ion incorporation into a beneficial screening mechanism. By intentionally allowing sodium ions to be incorporated during plating, then using a subsequent screening process to identify and eliminate affected devices, the method transforms a manufacturing defect into a quality control opportunity, ensuring only devices meeting threshold voltage specifications are produced.
Solution Approach 2:
The patent performs a preliminary screening action before final product completion. By implementing the threshold voltage screening process after plating but before final packaging, the method identifies and eliminates defective devices early in the manufacturing sequence, preventing defective products from reaching customers while maintaining high yield of good devices.
2Manufacturing precision
If threshold voltage screening is performed to eliminate defective devices, then product quality is improved, but manufacturing time and cost increase
Solution Approach 1:
The patent merges the threshold voltage screening process with existing manufacturing steps by performing the screening after plating and before final packaging. This integration allows the screening to be incorporated into the existing manufacturing flow without requiring separate dedicated screening equipment or processes, thereby minimizing additional time and cost investments while achieving high manufacturing precision.
3Stability of the object's composition
If high-temperature annealing is performed to diffuse sodium ions, then sodium ion distribution is improved, but device reliability may deteriorate due to excessive diffusion
Solution Approach 1:
The patent carefully controls the annealing parameters (temperature, time, atmosphere) to achieve optimal sodium ion diffusion without excessive penetration. By precisely adjusting these parameters, the method ensures sufficient diffusion to stabilize sodium ion distribution while preventing over-diffusion that could damage the semiconductor substrate or alter device characteristics, thus maintaining device reliability.
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 screens out semiconductor devices with threshold voltage variations, improving manufacturing efficiency and reducing defective packages, thereby lowering overall manufacturing costs.
Implementation Method 1
an annealing process that diffuses sodium ions within the interlayer insulating film to a significant extent
Implementation Method 2
a voltage applying process that incorporates a specific electric field to screen out defective devices
Data Source
AI summary
Provided is a fabrication method of a semiconductor device comprising an element forming process of forming a semiconductor element in a semiconductor substrate and forming a metal electrode above the semiconductor substrate; a plating process of plating the metal electrode; an annealing process of annealing the semiconductor substrate; a voltage applying process of applying a voltage corresponding to a thickness of the gate insulating film to the gate insulating film after the annealing process; and a judging process of measuring a threshold voltage of the semiconductor element after the voltage applying process, and judging a quality of the semiconductor element based on a measurement result.