Semiconductor Interconnect Air-Gap Structure for Lower Capacitive Coupling
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Solution Overview
Problem
As semiconductor technology advances, the increased density and reduced spacing between conductive features lead to higher capacitive coupling, increased power consumption, and longer RC time constants, posing challenges in device performance and manufacturing efficiency.
Innovation Solution
A semiconductor device structure is developed with specific dielectric and conductive layers and features, including conformal layers, barrier layers, and air gaps, to minimize capacitive coupling and improve electrical isolation, using methods like chemical vapor deposition (CVD) and chemical mechanical polishing (CMP) to achieve precise feature dimensions and electrical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the distance between adjacent conductive features is reduced 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 low-k dielectric material as an intermediary substance between adjacent conductive features. This intermediate layer has a dielectric constant (k value) less than 3.0, which acts as a mediator to reduce the electrostatic interaction and capacitive coupling between the conductive features while maintaining the reduced spacing required for high device density.
Solution Approach 2:
The patent changes the physical parameter of the dielectric material by selecting materials with specifically low dielectric constants (k < 3.0). This parameter change in the insulating material's electrical properties directly reduces the capacitive coupling effect between conductive features, allowing closer spacing without the harmful increase in capacitance that would normally occur.
2Productivity
If the distance between adjacent conductive features is reduced to increase density, then the device functionality is improved, but the power consumption increases
Solution Approach 1:
The low-k dielectric material serves as an intermediary that reduces parasitic capacitive effects between closely spaced conductive features. By minimizing these unwanted capacitances, the patent reduces the energy lost to charging and discharging of parasitic capacitors during signal transitions, thereby reducing overall power consumption while maintaining high device density.
Solution Approach 2:
The patent changes the dielectric constant parameter of the insulating material to a low value (k < 3.0), which directly reduces the capacitive coupling and associated energy losses. This parameter optimization allows the device to achieve high density without the penalty of increased power consumption that would result from higher capacitance values.
3Productivity
If the distance between adjacent conductive features is reduced to increase density, then the device functionality is improved, but the RC time constant increases
Solution Approach 1:
The patent optimizes the dielectric constant parameter (k value) of the insulating material to be less than 3.0, which directly reduces the capacitive component (C) of the RC time constant. Since the RC time constant is proportional to the dielectric constant, using low-k materials allows the patent to maintain reduced feature spacing while keeping the RC time constant within acceptable limits, thus preserving signal integrity and device reliability.
4Object-generated harmful factors
If conformal layers and barrier layers are added to reduce capacitive coupling, then the electrical isolation is improved, but the device complexity increases
Solution Approach 1:
The patent applies low-k dielectric material specifically in the regions between adjacent conductive features where capacitive coupling occurs, rather than uniformly changing the entire dielectric structure. Conformal and barrier layers are applied locally at interfaces where needed. This localized approach provides electrical isolation and reduces capacitive coupling only where necessary, minimizing the increase in overall device complexity while achieving the desired electrical performance.
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 solution effectively reduces capacitive coupling and power consumption, enhances device performance, and improves manufacturing efficiency by optimizing the semiconductor structure with controlled dielectric and conductive layers and air gaps.
Implementation Method 1
using methods like chemical vapor deposition (CVD)
Implementation Method 2
using methods like chemical vapor deposition (CVD) and chemical mechanical polishing (CMP)
Data Source
AI summary
A semiconductor device structure, along with methods of forming such, are described. The semiconductor device structure includes a device, a first conductive structure disposed over the device, and the first conductive structure includes a first sidewall having a first portion and a second portion. The semiconductor device structure further includes a first spacer layer disposed on the first portion, a second conductive structure disposed adjacent the first conductive structure, and the second conductive structure includes a second sidewall having a third portion and a fourth portion. The semiconductor device structure further includes a second spacer layer disposed on the third portion, and an air gap is formed between the first conductive structure and the second conductive structure. The second portion, the first spacer layer, the fourth portion, and the second spacer layer are exposed to the air gap.