Dispense Nozzle Shielding Device for Semiconductor Fabrication
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Solution Overview
Problem
Existing dispense nozzle systems in semiconductor fabrication face challenges in maintaining chemical purity and preventing particle generation due to evaporation and chemical reactions, particularly when the suck back feature is complex and costly, and external air can rapidly purge evaporated gases, leading to substrate defects.
Innovation Solution
A nozzle system with a shielding device, such as a shroud or shield gas, is used to create a mini-environment around the nozzle tip, maintaining a stable partial pressure of the dispense chemical and preventing external air from purging the evaporated gas, thus reducing evaporation and chemical reaction rates without the need for suck back valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If suck back valves are incorporated into the dispense valve to eliminate drips and reduce evaporation, then substrate defect prevention is improved, but system complexity and cost increase
Solution Approach 1:
The patent extracts the essential function of the suck back valve (maintaining chemical coverage at the nozzle tip) and implements it through a simpler mechanism: a heated capillary tube that uses capillary action and thermal energy to maintain a meniscus of chemical at the tip, eliminating the need for complex vacuum-based suck back hardware
Solution Approach 2:
The patent replaces the mechanical vacuum-based suck back system with a thermal-capillary system where a heated capillary tube uses thermal energy and capillary forces to maintain chemical coverage, simplifying the overall system architecture
2Productivity
If the dispense chemical is left exposed at the nozzle tip to maintain low partial pressure and high evaporation rate, then dispensing efficiency is improved, but particle generation increases due to rapid evaporation
Solution Approach 1:
The patent changes the temperature parameter of the nozzle tip and surrounding environment using integrated heating elements, maintaining the chemical in a liquid state at the tip while controlling the rate of evaporation to prevent particle formation, thus balancing dispensing efficiency with particle reduction
3Use of energy by moving object
If external air movements are allowed to purge evaporated gas from the nozzle tip, then evaporation rate is maintained, but chemical purity decreases due to airborne reactants
Solution Approach 1:
The patent creates an inert or controlled atmosphere around the nozzle tip using a laminar flow hood or enclosed chamber that limits exposure to airborne reactants, allowing controlled evaporation while protecting the chemical purity during the dispensing 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
This solution effectively minimizes particle generation and evaporation rates, preventing substrate defects by maintaining a stable chemical environment and protecting the dispense chemical from airborne reactants, while reducing system complexity and cost.
Implementation Method 1
the shielding device configured to create a mini-environment for a dispense chemical such that a partial pressure of the dispense chemical is maintained in the shielding device
Implementation Method 2
the dispense chemical is held at the tip of the nozzle by the surface tension of the dispense chemical
Implementation Method 3
the evaporated gas is quickly blown from the surface as the nozzle is moved from position to position, thereby maintaining a low partial pressure and a high evaporation rate
Implementation Method 4
a micro-environment is created in the vacated part of the tube where a high partial pressure can be maintained and which is only reduced via diffusion, a much slower process
Data Source
AI summary
Provided is a nozzle system for dispensing a dispense chemical onto a substrate, the system comprising: a nozzle comprising a nozzle body and a nozzle tip; a shielding device coupled to the nozzle tip, the shielding device configured to create a mini-environment for a dispense chemical such that a partial pressure of the dispense chemical is maintained in the shielding device; wherein the nozzle system is configured to meet selected dispense objectives.