Semiconductor Gate Dielectric Substitution for Parasitic Capacitance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor devices become smaller, the increased density and integration level lead to challenges in forming plugs between the source, drain, and gate of transistors, resulting in overly large parasitic capacitance due to high dielectric constant materials used in the cap layer, which degrades the performance of the semiconductor structure.
Innovation Solution
A method is introduced where a substitution layer with a smaller dielectric constant than the cap layer is formed in the trench created by removing the cap layer, reducing the average dielectric constant between the gate and plug structures, thereby minimizing parasitic capacitance and enhancing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a cap layer with high dielectric constant is used in the self-aligned process to form plugs, then the ease of manufacture is improved, but the parasitic capacitance increases leading to degraded performance
Solution Approach 1:
The patent changes the dielectric constant parameter of the material layer by replacing the high dielectric constant cap layer with a low dielectric constant substitution layer. This parameter change directly reduces parasitic capacitance while maintaining the structural integrity and manufacturing process compatibility, thereby resolving the contradiction between ease of manufacture and device performance
Solution Approach 2:
The patent discards the traditional cap layer after it has served its purpose in the self-aligned plug formation process. The cap layer is removed and replaced with a substitution layer, allowing the system to recover the manufacturing simplicity while eliminating the harmful high dielectric constant effect that degraded performance
2Reliability
If the cap layer is removed and replaced with a substitution layer of lower dielectric constant, then the parasitic capacitance is reduced improving performance, but the device complexity increases
Solution Approach 1:
The patent segments the originally single-function cap layer into two distinct functional layers: the removed cap layer that enabled self-aligned manufacturing, and the added substitution layer that provides low dielectric constant benefits. This segmentation allows each layer to perform its specific function optimally, improving performance while keeping the overall process manageable through clear functional separation
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
The use of a substitution layer with a lower dielectric constant effectively reduces parasitic capacitance, improving the performance and manufacturing yield of semiconductor structures by reducing the average dielectric constant between the gate and plug, thus addressing the degradation caused by high dielectric constant cap layers.
Implementation Method 1
The dielectric constant of the substitution layer is smaller than the dielectric constant of the cap layer
Data Source
AI summary
A method for fabricating a semiconductor structure includes providing a base substrate, including a substrate, a plurality of gate structures formed on the substrate, and a cap layer formed on the plurality of gate structures; removing the cap layer to form a trench on each gate structure; and forming a substitution layer in the trench. The dielectric constant of the substitution layer is smaller than the dielectric constant of the cap layer.