Air Gap Formation in Semiconductor Metal Lines
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Solution Overview
Problem
In advanced semiconductor manufacturing, the reduction of feature sizes leads to increased difficulty in filling trenches with dielectric material layers, resulting in air gaps with non-uniform shapes that are challenging to control, which in turn exacerbate resistance-capacitance (RC) delay and electronic signal interference.
Innovation Solution
A method involving the selective deposition of functionalized polymers on the lateral surfaces of metal lines, followed by a thermal annealing process to form air gaps, which are then filled with a low dielectric constant material, allowing for controlled size and shape of the air gaps to reduce RC delay and interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If feature sizes are reduced to continue scaling, then device density and integration are improved, but RC delay and electronic signal interference increase
Solution Approach 1:
The patent applies local quality by creating air gaps specifically in the trenches between adjacent metal lines, while the metal lines themselves remain continuous and functional. The air gap material (having different dielectric properties) is selectively placed only where needed to reduce capacitance between adjacent conductors, while maintaining the overall interconnect structure's electrical connectivity and mechanical integrity.
2Object-affected harmful factors
If dielectric material layer is deposited to fill trenches between metal lines, then RC delay is reduced, but manufacturing precision deteriorates due to non-uniform air gap shapes
Solution Approach 1:
The patent employs preliminary action by first forming a sacrificial material layer in the trenches between metal lines before depositing the dielectric material. This sacrificial layer serves as a template that defines the precise location and dimensions of future air gaps. After dielectric deposition, the sacrificial material is removed, creating uniformly shaped air gaps with controlled sizes and positions, thereby solving the manufacturing precision problem.
3Object-affected harmful factors
If air gaps are formed among metal lines, then RC delay and signal interference are reduced, but manufacturing complexity increases
Solution Approach 1:
The patent uses an intermediary approach by introducing a sacrificial material layer as a mediator in the manufacturing process. This sacrificial material temporarily occupies the space where air gaps will eventually form, enabling precise control over air gap geometry during dielectric deposition. The sacrificial material is then removed, leaving behind uniformly formed air gaps. This intermediary step simplifies the overall manufacturing process compared to attempting to form air gaps directly.
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 enables the formation of uniformly sized and shaped air gaps, effectively reducing RC delay and electronic signal interference in semiconductor devices, improving chip performance.
Implementation Method 1
forming a plurality of functionalized polymers on a lateral surface of a corresponding one of the metal lines
Implementation Method 2
a thermal annealing process to form air gaps
Implementation Method 3
removing the carbon-based polymer chain of the remainder of the functionalized polymers so as to form a plurality of air gaps
Implementation Method 4
filled with a low dielectric constant material, allowing for controlled size and shape of the air gaps
Data Source
AI summary
A method for manufacturing a semiconductor device includes: forming metal lines on a conductive interconnect structure disposed on a substrate; forming functionalized polymers, each of which includes a carbon-based polymer chain and a functional group that is bonded to a lateral surface of a corresponding one of the metal lines and that is represented by formula (A):wherein R1, R2, R3 are defined herein; removing the carbon-based polymer chain of an upper portion of the functionalized polymers to leave the carbon-based polymer chain of remainder of the functionalized polymers and to form recesses; forming a dielectric layer to fill the recesses; and removing the carbon-based polymer chain of the remainder of the functionalized polymers to form air gaps among the metal lines.