Dual Spacer Gate Structure for Parasitic Capacitance Reduction
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Solution Overview
Problem
As semiconductor devices undergo miniaturization, reducing parasitic capacitance becomes crucial to enhance operational speed, but existing methods are inadequate in effectively managing capacitance between gate electrodes and impurity junction regions.
Innovation Solution
The semiconductor device employs a dual spacer structure, with a low dielectric constant first spacer on the lower sidewall and a high dielectric constant second spacer on the upper sidewall of the gate electrode, fabricated using specific materials and processes to prevent parasitic capacitance generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single uniform dielectric constant material is used for the spacer, then the manufacturing process is simple, but parasitic capacitance between the gate electrode and impurity junction region cannot be effectively reduced
Solution Approach 1:
The spacer is divided into two distinct regions with different dielectric constants: a first spacer region adjacent to the impurity junction region with low dielectric constant to minimize parasitic capacitance, and a second spacer region adjacent to the gate electrode with high dielectric constant to maintain proper electrical isolation. This local differentiation of material properties allows each region to perform its specific function optimally.
Solution Approach 2:
The spacer structure employs a composite configuration combining materials with different dielectric constants in a single spacer component. This composite approach integrates the benefits of low dielectric constant materials (reduced parasitic capacitance) and high dielectric constant materials (effective electrical isolation) within one structural element, resolving the contradiction between simplicity and performance.
2Speed
If the dielectric constant of the spacer material is reduced to minimize parasitic capacitance, then operational speed increases, but electrical isolation between gate electrode and impurity junction region may be compromised
Solution Approach 1:
The spacer structure implements spatially varying dielectric constants: the first spacer region near the impurity junction uses low dielectric constant material to reduce parasitic capacitance and enhance speed, while the second spacer region near the gate electrode uses high dielectric constant material to ensure reliable electrical isolation. This local optimization resolves the contradiction between speed and reliability.
Solution Approach 2:
By combining materials with different dielectric constants in a composite spacer structure, the invention simultaneously achieves low parasitic capacitance (through the low dielectric constant region) and high electrical isolation (through the high dielectric constant region), thereby resolving the contradiction between operational speed and reliability.
3Productivity
If device miniaturization is pursued to increase integration, then device density increases, but parasitic capacitance management becomes more difficult
Solution Approach 1:
The dual-region spacer structure with differentiated dielectric constants provides a scalable solution for miniaturized devices. The low dielectric constant region specifically targets parasitic capacitance reduction at the critical impurity junction interface, while the high dielectric constant region maintains isolation, allowing the structure to function effectively even as device dimensions are reduced and integration density increases.
Solution Approach 2:
The composite spacer configuration enables effective parasitic capacitance management in scaled-down devices by integrating materials with complementary properties. This approach allows continued device miniaturization and integration while maintaining control over parasitic effects through the synergistic combination of low and high dielectric constant materials in the spacer structure.
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 configuration effectively reduces parasitic capacitance, thereby increasing the operational speed of semiconductor devices by optimizing the dielectric constant distribution and preventing capacitance formation between gate electrodes and impurity junction regions.
Implementation Method 1
a low dielectric constant first spacer on a lower sidewall of the first gate electrode
Implementation Method 2
a high dielectric constant second spacer on an upper sidewall of the first gate electrode
Data Source
AI summary
A semiconductor device can include a first gate electrode including a gate insulating pattern, a gate conductive pattern and a capping pattern that are sequentially stacked on a semiconductor substrate, and a first spacer of a low dielectric constant disposed on a lower sidewall of the first gate electrode. A second spacer of a high dielectric constant, that is greater than the low dielectric constant, is disposed on an upper sidewall of the first gate electrode above the first spacer.