Semiconductor Interconnect Structure With Hard Mask for Low Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing density and reduced spacing between conductive features in semiconductor integrated circuits lead to increased capacitive coupling, higher power consumption, and longer RC time constants, posing challenges in device performance and efficiency.
Innovation Solution
The implementation of a hard mask layer formed by materials different from the conductive features, which provides selective etch resistance and protects the conductive features during the formation of openings, thereby preventing damage and misalignment issues, followed by a capping layer to reduce capacitive coupling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the distance between conductive features is decreased to increase density, then the device functionality and performance are improved, but the capacitive coupling between conductive features increases
Solution Approach 1:
The patent introduces a dielectric layer as an intermediary substance between adjacent conductive features. This dielectric layer has a lower dielectric constant (k-value) than conventional materials, which reduces the capacitive coupling effect between neighboring conductors while allowing them to remain in close proximity for high density interconnects.
Solution Approach 2:
The patent changes the dielectric constant parameter of the insulating material between conductive features. By using materials with lower k-values, the capacitive coupling is reduced, allowing for decreased spacing between conductors without proportionally increasing capacitance, thus enabling higher density interconnect structures.
2Quantity of substance
If the spacing between conductive features is reduced to increase integration density, then more functionality is achieved, but the RC time constant increases
Solution Approach 1:
The patent modifies the dielectric constant parameter of the insulating material to reduce capacitance. By using low-k dielectric materials, the capacitive component of the RC time constant is reduced, allowing for reduced spacing between conductors without proportionally increasing the RC delay, thus improving signal transmission speed in high-density interconnects.
3Ease of manufacture
If conventional etching processes are used to form openings, then the process is simple, but damage to conductive features and misalignment issues occur
Solution Approach 1:
The patent applies a preliminary protective coating on the conductive features before the etching process. This protective layer is applied in advance to prevent damage to the conductors during subsequent etching operations, ensuring their structural integrity while allowing the etching process to proceed.
Solution Approach 2:
The patent introduces a protective intermediary layer between the etching chemistry and the conductive features. This protective layer acts as a mediator that allows the etching process to remove unwanted material while protecting the conductors from direct exposure to harsh etching conditions, preventing damage and improving alignment accuracy.
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 minimizes damage to conductive features during etching processes, maintains structural integrity, and reduces capacitive coupling, enhancing the performance and efficiency of semiconductor interconnects.
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
Data Source
AI summary
An interconnect structure includes a dielectric layer, a first conductive feature, a hard mask layer, a conductive layer, and a capping layer. The first conductive feature is disposed in the dielectric layer. The hard mask layer is disposed on the first conductive feature. The conductive layer includes a first portion and a second portion, the first portion of the conductive layer is disposed over at least a first portion of the hard mask layer, and the second portion of the conductive layer is disposed over the dielectric layer. The hard mask layer and the conductive layer are formed by different materials. The capping layer is disposed on the dielectric layer and the conductive layer.