Epitaxy Chamber Edge Gas Control for Cross-Hatch Defect Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing epitaxial processing chambers suffer from cross-hatching defects at the bevel and edge areas of substrates due to lattice mismatch and stress, which propagate into the main film area, particularly in heteroepitaxy processes.
Innovation Solution
The processing chamber incorporates gas flow systems to control film thickness and growth rate at the edge area by using dilution, purge, and etchant gases, along with radiant heaters to adjust temperature, reducing defects through controlled film formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If heteroepitaxy is performed to deposit materials on substrate, then film deposition is achieved, but cross-hatching defects occur at edge area due to lattice mismatch and stress
Solution Approach 1:
The patent applies local quality by introducing an auxiliary gas flow that specifically targets the edge area of the substrate. This creates a localized modification of deposition conditions at the problematic edge region, where the auxiliary gas reduces the deposition rate or temporarily stops deposition. This local intervention prevents cross-hatching defects at the edge while maintaining normal deposition conditions and film thickness in the central area, thus resolving the contradiction between film thickness and film quality.
2Manufacturing precision
If Ge concentration and SiGe thickness are increased to achieve desired film composition, then film composition is improved, but cross-hatching defects worsen at bevel and edge area
Solution Approach 1:
The patent implements preliminary anti-action by applying an auxiliary gas flow to the edge area before cross-hatching defects can propagate inward from the bevel and edge regions. The auxiliary gas creates a protective effect at the edge area, preventing the initiation and propagation of defects. This preliminary protective action allows the use of higher Ge concentration and SiGe thickness in the central film composition without suffering from the usual defect propagation problem, thus resolving the contradiction between film composition and harmful defects.
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 mitigates cross-hatching defects at the edge and bevel areas, allowing for thicker film stacks without defects and maintaining film quality across the substrate.
Implementation Method 1
Epitaxy (EPI) has been widely used in depositing materials on surfaces of semiconductor substrates and devices
Implementation Method 2
A plasma may be used to facilitate the growth of epitaxial layers on the substrate
Implementation Method 3
an auxiliary gas channel configured to flow an auxiliary gas toward an edge area of the substrate
Implementation Method 4
a purge gas channel configured to flow a purge gas into a space below the susceptor, wherein the susceptor has a plurality of apertures disposed in a peripheral area thereof and configured to allow the purge gas to pass through to the edge area of the substrate
Data Source
AI summary
Disclosed herein is a processing chamber. In one embodiment, the processing chamber includes a substrate support assembly comprising a susceptor configured to support a substrate within a processing region within the processing chamber, a deposition gas channel configured to flow a deposition gas across an upper surface of the substrate, an auxiliary gas channel configured to flow an auxiliary gas toward an edge area of the substrate, and a separator disposed between the deposition gas channel and the auxiliary gas channel.