Selective Spray Etch for Semiconductor Chamber Cleaning
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Solution Overview
Problem
In semiconductor, flat panel, and solar power panel manufacturing, process chamber components often become unintentionally coated with films, leading to contamination issues when traditional in-situ cleaning methods fail or are ineffective, resulting in the need for ex-situ cleaning to prevent over-etching and equipment damage.
Innovation Solution
A method involving spraying cleaning chemistry onto chamber components, followed by DI water pressure washing and treatment with potassium hydroxide, allows for selective removal of unintentional coatings without over-etching intentional coatings, using a spray apparatus with rotating and linearly moving nozzles to direct the cleaning solution from multiple directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional in-situ cleaning methods are used, then the chamber environment can be maintained clean, but they become ineffective when thick unintentional coatings accumulate
Solution Approach 1:
The patent changes the cleaning methodology from in-situ to ex-situ, and from uniform chemical exposure to selective spray etching with controlled chemistry parameters (HF:HNO3 ratios, temperature, concentration) to effectively remove thick unintentional coatings while preserving intentional coatings
Solution Approach 2:
The cleaning process is segmented into multiple sequential steps: acid spray etching followed by potassium hydroxide treatment, with each step targeting specific types of coatings. The spray apparatus also segments the cleaning action by directing chemicals from multiple directions onto different surfaces
2Reliability
If uniform chemical spray is applied to remove thick coatings, then cleaning effectiveness improves, but intentional coatings may be damaged
Solution Approach 1:
The patent applies different chemical treatments to different areas and types of coatings. The spray etching process uses selective chemistry (HF:HNO3 in specific ratios) that etches unintentional coatings at different rates than intentional coatings, allowing differential treatment based on coating type and location
Solution Approach 2:
The process uses controlled excessive action with spray etching to ensure complete removal of thick unintentional coatings, then follows with potassium hydroxide treatment to remove any residual intentional coating material, achieving complete cleaning without over-etching through staged application
3Reliability
If acid bath dipping is used to clean chamber components, then thorough cleaning is achieved, but violent reactions and heat generation occur
Solution Approach 1:
The patent replaces liquid acid bath dipping with a spray-based hydraulic system that delivers cleaning chemistry as a controlled spray. This allows for better heat dissipation through evaporation and reduced chemical inventory in contact with the component at any one time, minimizing violent reactions and heat generation
Solution Approach 2:
The spray process applies cleaning chemistry in controlled stages rather than complete immersion, allowing incremental cleaning with better thermal management. The process can be paused and adjusted to control reaction intensity and heat generation
4Object-affected harmful factors
If ex-situ cleaning is performed, then contamination risks are reduced, but chemical usage and processing time increase
Solution Approach 1:
The patent uses periodic spray cycles with alternating acid and base treatments, followed by rinsing stages. This periodic application allows chemicals to work incrementally and be flushed away regularly, reducing total chemical usage compared to prolonged immersion while maintaining effective cleaning
Solution Approach 2:
The process discards spent cleaning chemicals after each spray cycle and replaces them with fresh chemistry, ensuring consistent cleaning effectiveness without accumulating excess chemicals. Used chemicals are discarded rather than reused to prevent contamination
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 effectively removes thick unintentional coatings without damaging thin areas, reduces chemical usage and heat generation, and minimizes contamination risks, enabling safer and more efficient cleaning of chamber components.
Implementation Method 1
spraying the part with an acid
Implementation Method 2
spraying the part with DI water
Implementation Method 3
treating the part with potassium hydroxide
Data Source
AI summary
In one aspect, a method of cleaning an electronic device manufacturing process chamber part is provided, including a) spraying the part with an acid; b) spraying the part with DI water; and c) treating the part with potassium hydroxide. Other aspects are provided.