Chelating Vapor Cleaning for HAR Substrates Without Pattern Collapse
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Solution Overview
Problem
Pattern collapse occurs during wet cleaning of substrates with high aspect ratio (HAR) structures, leading to performance issues and defects due to contamination from metals like stainless steel, chromium, nickel, and molybdenum, which are not effectively removed by existing methods.
Innovation Solution
A vapor mixture comprising metal chelating vapors such as β-diketones and derivatives, along with optional oxidizing gases, is used to clean substrates at controlled pressures and temperatures, converting metals to volatile compounds without causing structural collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wet cleaning is performed to clean substrates, then metal contamination is removed, but pattern collapse occurs on high aspect ratio structures
Solution Approach 1:
The patent replaces wet cleaning (mechanical/liquid-based) with vapor-phase cleaning using a metal chelating vapor mixture. This substitution eliminates the mechanical forces and liquid exposure that cause pattern collapse while maintaining effective metal contamination removal through chemical chelation in the vapor phase.
Solution Approach 2:
The patent changes the physical state parameter from liquid (wet cleaning) to vapor phase (vapor cleaning), and controls temperature and pressure parameters to maintain structures in a stable state during cleaning, preventing collapse while enabling effective contamination removal.
2Object-affected harmful factors
If high aspect ratio structures are cleaned using conventional methods, then metal contamination is addressed, but structure collapse and lateral movement occur
Solution Approach 1:
The patent creates an inert vapor-phase environment using a metal chelating vapor mixture that chemically binds to metal contaminants without causing structural damage. This inert chemical environment removes harmful metal contamination while maintaining structure stability through controlled vapor-phase interaction rather than aggressive liquid or plasma methods.
3Manufacturing precision
If vapor cleaning with metal chelating vapor is used, then metal contamination is removed without pattern collapse, but non-metallic components or coatings are required in the processing chamber
Solution Approach 1:
The patent extracts or removes metallic components from the processing chamber environment by using non-metallic materials or coatings. This extraction eliminates the source of metal contamination that would react with the metal chelating vapor, enabling effective cleaning while preventing chamber material interference with the cleaning process.
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 method effectively removes metal contamination from HAR structures without pattern collapse, ensuring clean substrates for downstream processing by forming stable volatile metal compounds at moderate temperatures.
Implementation Method 1
supplying a vapor mixture including a metal chelating vapor for a first period to remove metal contamination from surfaces of the substrate
Implementation Method 2
supplying an oxidizing gas mixture to the processing chamber for a second period
Data Source
AI summary
A method for cleaning a substrate includes arranging the substrate in a processing chamber; controlling a pressure of the processing chamber to a predetermined pressure range; controlling a temperature of the processing chamber to a predetermined temperature range; and supplying a vapor mixture including a metal chelating vapor for a first period to remove metal contamination from surfaces of the substrate.