Selective Air Gap Formation in Interlayer Dielectrics
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Solution Overview
Problem
As semiconductor devices integrate more densely, leakage current issues arise due to electron tunneling and metal element diffusion, necessitating the use of high-k and low-k materials, but existing methods for forming air gaps face challenges in maintaining sufficient gap size and preventing interference between pattern structures.
Innovation Solution
A substrate processing method involving the formation of fluorine-terminated and hydrogen-terminated sites on a pattern structure, followed by selective deposition of an interlayer insulating layer, creates an air gap by inhibiting deposition in lower spaces and promoting it in upper spaces using controlled plasma conditions and gas supply cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an air gap is formed by deposition overhang method, then the air gap can be formed between pattern structures, but the gap size is insufficient and interference between pattern structures occurs
Solution Approach 1:
The patent applies preliminary action by forming terminated sites (fluorine-terminated and hydrogen-terminated) on the pattern structure surface before the deposition process. This preliminary surface treatment creates specific chemical states that control where deposition will occur, ensuring the air gap forms with sufficient size and proper positioning to prevent interference between pattern structures.
Solution Approach 2:
The patent implements local quality by creating different terminated sites at different locations on the pattern structure surface. Fluorine-terminated sites are formed in regions where deposition should be inhibited, while hydrogen-terminated sites are formed where deposition should proceed. This spatial differentiation of surface properties enables precise control over the air gap formation and prevents interference between adjacent pattern structures.
2Area of stationary object
If high-k material is used for dielectric, then dielectric area is increased, but leakage current occurs due to electron tunneling
Solution Approach 1:
The patent uses composite materials by combining air (lowest dielectric constant) with solid dielectric materials. The air gap structure creates a composite dielectric system where the air regions provide electrical isolation to prevent leakage current and electron tunneling, while the solid dielectric materials maintain the necessary capacitance. This composite approach allows increased dielectric area without the harmful effects of pure high-k materials.
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 method effectively prevents interference and maintains a sufficient air gap size, reducing leakage current and enhancing dielectric properties by selectively forming the interlayer insulating layer, thus improving semiconductor device performance.
Implementation Method 1
forming of the first terminated sites may be performed under a plasma condition of a first frequency, and the forming of the second terminated sites may be performed under a plasma condition of a second frequency
Implementation Method 2
supplying a source gas having reactivity with the second terminated sites; and supplying a reactive gas
Implementation Method 3
the source gas may include a silicon precursor, and Si—H-terminated sites may be formed by the supplying of the source gas
Data Source
AI summary
A substrate processing method of forming an air gap includes: forming deposition inhibitor sites in a lower space between a first protrusion and a second protrusion; and forming film-forming sites and an interlayer insulating layer on the first protrusion and the second protrusion, wherein the interlayer insulating layer is selectively formed in an upper space between the first protrusion and the second protrusion by the deposition inhibitor sites and the film-forming layer, and thus an air gap is formed between the first protrusion and the second protrusion.