Cryogenic Fluid Mixture Nozzle for Microelectronic Substrate Cleaning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Advanced microelectronic IC manufacturing requires effective techniques to remove smaller particles from microelectronic substrates without damaging the substrate, as smaller device features make them more susceptible to damage from particles.
Innovation Solution
The use of cryogenic aerosols and gas cluster jet sprays formed by expanding fluid mixtures from high pressure to sub-atmospheric pressure, with specific nozzle designs and fluid compositions to minimize liquification and optimize particle removal efficiency, allowing for a wider cleaning area without damaging the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional cleaning techniques are used to remove particles from microelectronic substrates, then particle removal is achieved, but substrate damage occurs due to the susceptibility of smaller device features
Solution Approach 1:
The patent changes the physical parameters of the cleaning fluid by using cryogenic temperatures and controlling phase transitions. The fluid is maintained in a controlled phase state (between gas and liquid) to provide effective particle removal while minimizing substrate damage through reduced kinetic energy transfer.
Solution Approach 2:
The patent utilizes phase transitions of the cryogenic fluid as a core mechanism. The fluid transitions between gas and liquid phases during the cleaning process, with the phase change occurring near the substrate surface to enhance particle removal efficiency while controlling the intensity of interaction to prevent damage.
2Manufacturing precision
If cryogenic fluids are used to remove smaller particles, then particle removal efficiency improves, but substrate damage may increase due to fluid intensity
Solution Approach 1:
The patent applies local quality by creating a gradient in fluid intensity across the treatment area. The phase transition and fluid expansion are concentrated at the substrate surface where particle removal is needed, while the bulk fluid remains in a less intense state, providing localized effective cleaning without overwhelming the substrate.
Solution Approach 2:
The patent uses partial action by controlling the degree of phase transition and fluid expansion. Rather than complete liquefaction, the fluid is partially transitioned to provide sufficient cleaning action for sub-100 nm particles while maintaining enough gas phase character to reduce damage risk through lower kinetic energy transfer.
3Productivity
If traditional cleaning methods are used, then processing is simple, but cleaning area is limited requiring multiple passes and increasing cycle time
Solution Approach 1:
The patent segments the cleaning process into controlled phases: fluid delivery, phase transition at substrate surface, particle removal, and fluid evacuation. This segmentation allows each stage to be optimized independently, enabling larger cleaning areas per pass while maintaining process control and reducing overall cycle time.
Solution Approach 2:
The patent employs pneumatic principles by using controlled gas expansion and pressure differentials to deliver the cryogenic fluid and create the phase transition. The pneumatic system enables precise control over fluid delivery and evacuation, allowing larger treatment areas to be processed efficiently in single passes.
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 method improves particle removal efficiency for sub-100 nm particles while maintaining efficiency for larger particles, reduces substrate damage, and increases the cleaning area size, thereby reducing cycle time and chemical costs.
Implementation Method 1
the expansion of the fluid mixture from a high pressure (e.g., greater than atmospheric pressure) environment to a lower pressure environment (e.g., sub-atmospheric pressure)
Implementation Method 2
The damage reduction may have been enabled by avoiding liquification
Data Source
AI summary
Disclosed herein are systems and methods for treating the surface of a microelectronic substrate, and in particular, relate to an apparatus and method for scanning the microelectronic substrate through a cryogenic fluid mixture used to treat an exposed surface of the microelectronic substrate. The fluid mixture may be expanded through a nozzle to form an aerosol spray or gas cluster jet (GCJ) spray and may impinge the microelectronic substrate and remove particles from the microelectronic substrate's surface. In one embodiment, a two-stage gas nozzle may be used to expand a fluid mixture with a liquid phase concentration of greater than 10% by weight.