Air Gap Stability in Interconnect Dielectric Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor technology, the collapse of air gaps in low-k dielectric materials used in damascene processes for forming interlayer dielectrics leads to performance and quality issues in integrated circuits, particularly in large spacing regions.
Innovation Solution
A method involving the formation of an energy removal film with non-uniformly distributed air gaps, where the air gaps are primarily formed between conductive features with small spacing, using a ceiling layer to prevent collapse by applying energy to the energy removal film after forming conductive features and a ceiling layer, ensuring air gaps are predominantly created in regions with small spacing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If air gaps are provided in low-k dielectric materials to reduce dielectric constant, then the dielectric performance is improved, but the air gaps collapse in large spacing regions causing performance and quality issues
Solution Approach 1:
The patent applies local quality by creating non-uniform air gap distribution where the ceiling layer is selectively positioned only over small spacing regions between conductive features. This localized approach allows air gaps to be maintained where they provide benefit (small spacing regions) while avoiding collapse in large spacing regions where the ceiling layer is absent, thus resolving the contradiction between dielectric performance and air gap stability.
2Reliability
If air gaps are created in large spacing regions, then the dielectric constant is reduced, but the air gaps collapse leading to performance degradation
Solution Approach 1:
The ceiling layer is selectively formed only in small spacing regions, creating a local quality distinction that prevents air gap collapse in those specific areas. This localized ceiling layer formation maintains manufacturing precision by avoiding the collapse issue entirely in the regions where it would occur, while still achieving dielectric constant reduction in the appropriate regions.
3Stability of the object's composition
If a ceiling layer is formed to prevent air gap collapse, then air gap stability is improved, but the ceiling layer must be selectively formed only in small spacing regions increasing process complexity
Solution Approach 1:
The patent applies preliminary action by forming the ceiling layer after the air gaps have already been created in the energy removal material. This sequence allows the air gaps to be established first, then the ceiling layer is selectively added in small spacing regions to prevent collapse. This preliminary formation of air gaps followed by selective ceiling layer deposition reduces process complexity compared to attempting to pattern the ceiling layer before air gap formation.
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 reduces or eliminates air gap collapse, enhancing the performance and reliability of integrated circuits by maintaining air gaps within regions defined by conductive features with small spacing, thereby improving the structural integrity and functionality of the circuit.
Implementation Method 1
an energy removal film (ERF) overlying a substrate and having non-uniformly distributed air gaps formed therein. The air gaps in the ERF are formed in regions defined between proximate conductive features with small spacing
Implementation Method 2
a ceiling layer overlying the ERF and the conductive features. The air gaps in the ERF are formed after the ceiling layer is formed, and the ceiling layer prevents collapse of the air gaps
Data Source
AI summary
The present disclosure provides a method for fabricating an integrated circuit. The method includes forming an energy removable film (ERF) on a substrate; forming a first dielectric layer on the ERF; patterning the ERF and first dielectric layer to form a trench in the ERF and the first dielectric layer; filling a conductive material in the trench; forming a ceiling layer on the first dielectric layer and conductive material filled in the trench; and applying energy to the ERF to form air gaps in the ERF after the forming of the ceiling layer.