Gas-Atomized Prewetting Chamber for Bubble-Free Wafer Features
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pre-wetting techniques for semiconductor wafers fail to consistently fill features with metal ions due to trapped gas bubbles and residual process materials, leading to defects in plating and interconnect failures, especially in features with high aspect ratios.
Innovation Solution
A method and system utilizing gas atomized wetting and cleaning agents, combined with substrate rotation and controlled atmospheres or vacuums, to ensure thorough wetting and cleaning of semiconductor features, using gases like CO2 or nitrogen with higher solubility in the wetting agent to dissolve trapped gases and residues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid immersion or spraying is used for pre-wetting, then the substrate surface is wetted, but trapped gas bubbles prevent complete wetting of recessed features
Solution Approach 1:
The patent introduces a gas atomization intermediary that breaks liquid into fine droplets suspended in gas flow. This intermediary mechanism allows the liquid to penetrate recessed features without forming trapped gas bubbles, as the atomized droplets are carried by gas flow deep into vias and trenches, solving the contradiction between wetting completeness and gas bubble entrapment.
Solution Approach 2:
The patent replaces conventional liquid immersion or spraying mechanical systems with a gas atomization system. Instead of relying on liquid flow mechanics that create surface tension barriers and trapped bubbles, the system uses gas flow dynamics to deliver atomized liquid droplets, substituting the mechanical delivery mechanism to achieve complete feature wetting without gas entrapment.
2Reliability
If conventional pre-wetting methods are used, then some wetting is achieved, but residual process materials remain in vias blocking plating chemistries
Solution Approach 1:
The gas atomization process acts as an intermediary cleaning mechanism that delivers liquid deep into vias and trenches where residual materials block plating. The fine atomized droplets penetrate areas inaccessible to conventional spraying, effectively removing residual process materials and enabling complete plating chemistry access to all feature surfaces.
Solution Approach 2:
The gas atomized pre-wetting and cleaning process performs preliminary removal of residual process materials before plating begins. By thoroughly cleaning and wetting all feature surfaces in advance, the system prevents blocking sites from forming during subsequent plating operations, ensuring complete metal deposition in all areas.
3Area of stationary object
If more liquid is sprayed to ensure complete wetting, then wetting coverage increases, but surface tension prevents liquid from contacting all recessed surfaces
Solution Approach 1:
The patent changes the physical parameters of the liquid delivery system by atomizing the liquid into fine droplets and suspending them in gas flow. This parameter change reduces liquid cohesiveness and surface tension effects, allowing the liquid to disperse and contact all recessed surfaces uniformly, achieving complete wetted surface area with precise feature filling control.
Solution Approach 2:
The patent segments the liquid into numerous fine droplets through gas atomization. This segmentation breaks the liquid into small units that can individually penetrate and wet recessed surfaces, overcoming surface tension barriers that prevent conventional liquid streams from contacting all feature surfaces, thereby achieving complete area coverage with precise filling.
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
Effectively removes trapped gases and residues, ensuring complete wetting and cleaning of semiconductor features, reducing defects and enhancing plating quality for improved electrical conductivity.
Implementation Method 1
using gases like CO2 or nitrogen with higher solubility in the wetting agent to dissolve trapped gases and residues
Implementation Method 2
spraying the substrate with a gas atomized wetting and cleaning agent
Data Source
AI summary
A semiconductor substrate wetting and cleaning system includes a processing chamber (12) and a rotatable head disposed in the processing chamber. A coupler or chuck (24) couples a semiconductor substrate or wafer (18) to the rotatable head. At least one gas atomized spray nozzle (20) is directed at the semiconductor substrate (18) when coupled to the coupler. A source (21) of wetting/cleaning fluid is in flow communication with the spray nozzle (20), and a source (23) of atomizing gas also is in flow communication with the spray nozzle (20) to atomize the wetting/cleaning fluid.