Remote Plasma Seasoning for Gapfill Void Reduction
Solution Overview
Problem
In the semiconductor industry, high-density plasma CVD techniques often result in voids in narrow gaps due to lack of mobility, and flowable materials like spin-on glass face film shrinkage issues during curing, leading to stress and delamination problems.
Innovation Solution
A remote plasma system is seasoned by flowing a silicon-containing precursor to deposit a protective silicon-containing film on the interior surfaces, reducing reactions and enhancing deposition uniformity and rate, while exciting oxygen radicals in a chamber plasma region to grow films with reduced organic content and shrinkage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high-density plasma CVD is used to fill narrow gaps, then perpendicular impingement trajectories and sputtering activity are achieved, but voids develop due to lack of mobility
Solution Approach 1:
The patent applies a preliminary seasoning treatment to the chamber walls before dielectric deposition. This involves exposing the chamber walls to plasma and/or chemical treatments that modify the wall surface properties, creating a more uniform and controlled environment for subsequent film deposition. This preliminary action prevents void formation by ensuring uniform nucleation and growth conditions across the chamber surfaces.
2Manufacturing precision
If flowable materials like spin-on glass are used to fill gaps, then gap filling capability is improved, but significant film shrinkage occurs during cure leading to stress and delamination
Solution Approach 1:
The patent modifies the chemical composition and physical parameters of the flowable dielectric material to reduce shrinkage during curing. This includes adjusting the polymer composition, crosslinking density, and curing conditions to minimize volume contraction. By changing these parameters, the material maintains gap-filling capability while reducing film stress and delamination risks.
3Manufacturing precision
If low viscosity materials are used for gapfill, then deposition uniformity and planarization are enhanced, but significant shrinkage during cure results in high film stress
Solution Approach 1:
The patent develops composite dielectric materials that combine low-viscosity components for good gap-filling and uniformity with shrinkage-reducing components. This may involve blending different polymer systems, adding fillers, or creating multi-layer structures where each component contributes specific properties. The composite formulation achieves both deposition uniformity and reduced film stress.
4Manufacturing precision
If separated precursor delivery channels are used, then flowable film formation is enabled, but time available for adsorbed species mobility is limited resulting in nonuniform films
Solution Approach 1:
The patent introduces a preliminary plasma treatment or wall conditioning step before precursor delivery. This preliminary action prepares the chamber walls to promote uniform adsorption and mobility of precursor species, compensating for the reduced time available for these processes. The wall treatment creates uniform nucleation sites and enhances surface diffusion, ensuring film uniformity despite the time constraints of separated delivery channels.
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 improves deposition rate and uniformity, reduces defectivity, and maintains satisfactory growth rates with low defectivity, addressing voids and shrinkage issues in gapfill processes.
Implementation Method 1
flowing a silicon-containing precursor into a remote plasma region to deposit a silicon containing film on an interior surface of the remote plasma system
Implementation Method 2
depositing and etching films on a substrate... High-density plasma (HDP)-CVD has been used to fill many geometries
Implementation Method 3
exciting oxygen radicals in a chamber plasma region to grow films with reduced organic content and shrinkage
Data Source
AI summary
Methods of seasoning a remote plasma system are described. The methods include the steps of flowing a silicon-containing precursor into a remote plasma region to deposit a silicon containing film on an interior surface of the remote plasma system. The methods reduce reactions with the seasoned walls during deposition processes, resulting in improved deposition rate, improved deposition uniformity and reduced defectivity during subsequent deposition.