Semiconductor Interconnect Structure With Air Gaps for Lower Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor technology advances, the increasing density of integrated circuits leads to reduced dimensions and spacing between conductive features, resulting in increased capacitance and power consumption due to capacitive coupling, which poses challenges for device performance and efficiency.
Innovation Solution
The implementation of an interconnect structure that includes an air gap between conductive features, formed by a sacrificial layer and support layer, reduces capacitive coupling by creating a dielectric fill and etch stop layers with different etch selectivity, thereby minimizing line-to-line leakage and enhancing breakdown voltage reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the distance between conductive features is reduced to increase density, then the element density increases, but the capacitance and power consumption increase due to capacitive coupling
Solution Approach 1:
A low-k dielectric material is introduced as an intermediary substance between adjacent conductive features. This dielectric layer has a lower dielectric constant than conventional materials, which reduces the capacitive coupling between conductors while maintaining the reduced spacing needed for high density. The dielectric acts as a mediator that allows close proximity without the harmful capacitive effects.
2Quantity of substance
If the distance between conductive features is reduced to increase density, then the element density increases, but the RC time constant increases
Solution Approach 1:
The dielectric constant parameter of the insulating material is changed from conventional values to lower values. By selecting and implementing low-k dielectric materials with reduced dielectric constants, the patent directly modifies this physical parameter to decrease capacitance and consequently reduce the RC time constant, enabling faster signal propagation despite reduced feature spacing.
3Use of energy by moving object
If air gap is introduced to reduce capacitive coupling, then the power consumption decreases, but the device structure becomes more complex
Solution Approach 1:
The dielectric layer is segmented into multiple functional layers including the low-k dielectric material layer and an overlying etch stop layer. This segmentation allows each layer to perform its specific function - the low-k dielectric reduces capacitive coupling while the etch stop layer provides mechanical support and process control - thereby managing the structural complexity through functional decomposition.
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 reduces capacitive coupling, decreases power consumption, and improves the reliability of semiconductor devices by maintaining isolation and preventing line-to-line leakage, thus addressing the limitations of traditional semiconductor manufacturing techniques.
Implementation Method 1
the resulting capacitance (a function of the dielectric constant (k value) of the insulating material divided by the distance between the conductive features) increases. This increased capacitance results in increased capacitive coupling between the conductive features
Implementation Method 2
The implementation of an interconnect structure that includes an air gap between conductive features, formed by a sacrificial layer and support layer, reduces capacitive coupling by creating a dielectric fill
Data Source
AI summary
An interconnect structure includes a dielectric layer, a conductive feature, a conductive layer, a capping layer, a support layer and an etch stop layer. The conductive feature is disposed in the dielectric layer. A first portion of the conductive layer is disposed over the first conductive feature, and a second portion of the conductive layer is disposed over the dielectric layer. A first portion of the capping layer is in contact with the first portion of the conductive layer, a second portion of the capping layer is in contact with the second portion of the conductive layer, and a third portion of the capping layer is in contact with the dielectric layer. An air gap is defined by the support layer and the capping layer. The etch stop layer is disposed over the second portion of the conductive layer, the second portion of the capping layer and the support layer.