Sputtering Shield Overlap Structure for Particle Suppression
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Solution Overview
Problem
Existing film forming apparatuses suffer from the generation of particles due to the scattering of sputtered particles outside the processing space, leading to potential contamination and inefficiencies.
Innovation Solution
The film forming apparatus incorporates a shield structure with a double pipe configuration, where the target shield and chamber shield form a cylindrical overlap, and a trap structure to capture and redirect sputtered particles, combined with labyrinth structures in the gas channels to prevent particle scattering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple shield structure is used to define processing space, then device complexity is reduced, but particle generation increases due to sputtered particle scattering outside the processing space
Solution Approach 1:
The patent implements a nested shield structure where an inner shield is positioned within an outer shield, creating multiple containment layers. The inner shield has a smaller diameter and is axially offset from the outer shield, forming a nested configuration that effectively traps sputtered particles without requiring excessive structural complexity
Solution Approach 2:
The patent resolves the contradiction by introducing axial positioning as an additional dimension for particle control. The inner shield is positioned at a different axial location than the outer shield, creating an overlapping region that forms an effective particle trap. This dimensional approach allows particle suppression without simply increasing shield diameter or complexity linearly
2Device complexity
If sputtered particles are allowed to scatter outside processing space, then device complexity is reduced, but manufacturing precision deteriorates due to particle contamination
Solution Approach 1:
The patent converts the potentially harmful scattered sputtered particles into a beneficial effect by using them to form a particle trap. The overlapping region between inner and outer shields creates a controlled zone where particles are redirected onto designated surfaces, transforming what would be contamination into a controlled deposition mechanism that protects the substrate
Solution Approach 2:
The inner shield acts as an intermediary element between the target and the substrate. It intercepts sputtered particles that would otherwise scatter uncontrollably, redirecting them onto the inner shield's own surfaces or into controlled regions, thereby protecting the substrate from contamination while maintaining film formation quality
3Object-generated harmful factors
If a double pipe shield structure with overlapping cylindrical portions is used, then particle suppression is improved, but device complexity increases
Solution Approach 1:
The patent divides the shield into distinct segments: an outer shield and an inner shield, each with specific functional roles. The outer shield provides primary containment while the inner shield creates the overlapping trap region. This segmentation allows each component to be optimized independently, reducing overall complexity compared to a monolithic design
Solution Approach 2:
The patent merges the particle containment function and the particle trapping function into a single integrated shield structure. The overlapping region between inner and outer shields simultaneously serves as both a containment boundary and a particle trap, eliminating the need for separate trapping mechanisms and reducing overall structural complexity
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 design effectively suppresses the generation of particles by trapping and redirecting sputtered particles, maintaining a clean processing environment and enhancing film formation efficiency.
Implementation Method 1
a target disposed in the processing chamber to emit sputtered particles
Data Source
AI summary
There is provided a film forming apparatus comprising a processing chamber including a processing chamber main body and a lid, a stage, a target, and a shield. The shield has a chamber shield fixed to the processing chamber main body and a target shield fixed to the lid. The chamber shield has a cylindrical sidewall and a horizontal wall formed at a radially outer side of the cylindrical sidewall. The target shield has a cylindrical portion extending toward the stage. A diameter of an outer peripheral surface of the cylindrical portion is smaller than a diameter of an inner peripheral surface of the cylindrical sidewall, and the cylindrical portion and the cylindrical sidewall form a double pipe structure in which the cylindrical portion and the cylindrical sidewall overlap at least partially in a height direction.