Semiconductor Substrate Wetting via Controlled Atmosphere and Pressure Modulation
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Solution Overview
Problem
Conventional semiconductor processing technologies face challenges in achieving complete wetting of vias and other features on substrates, leading to defects and inefficiencies in electroplating due to trapped air bubbles, which are difficult to remove and can result in reduced substrate throughput and device performance.
Innovation Solution
The method involves creating a controlled atmosphere in a processing chamber with reduced pressure and using a wetting agent, such as degassed deionized water, that can effectively absorb and displace residual gases, including carbon dioxide, to reduce bubble defects and improve wetting efficiency, with the chamber pressure being maintained below 100 kPa and subsequently pressurized to atmospheric conditions to enhance gas absorption and diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wetting methods are used in atmospheric conditions, then the process is simple and quick, but air bubbles remain trapped in vias causing defects
Solution Approach 1:
The system performs preliminary actions by reducing chamber pressure before introducing the wetting agent, and by degassing the wetting agent beforehand. This preparatory vacuum treatment removes air from vias before wetting, preventing bubble entrapment without requiring complex post-processing steps
Solution Approach 2:
The patent creates an inert-like environment by evacuating air from the processing chamber and replacing it with a controlled atmosphere during wetting. This eliminates oxygen and nitrogen from the via interiors, preventing bubble formation while maintaining process simplicity through integrated chamber control
2Reliability
If pressure is reduced to remove air bubbles, then bubble defects are reduced, but processing time increases
Solution Approach 1:
The system maintains continuous useful action by integrating pressure reduction, wetting agent introduction, and bubble removal into a single continuous process cycle. The vacuum chamber remains sealed and pressurized throughout, eliminating the need for separate processing steps and reducing total cycle time
Solution Approach 2:
The patent utilizes parameter changes by dynamically adjusting chamber pressure during the wetting process - reducing pressure to facilitate bubble removal, then rapidly pressurizing to complete the wetting action. This timed pressure modulation achieves effective bubble removal while minimizing processing time
3Reliability
If degassed deionized water is used as wetting agent, then gas absorption is improved, but the requirement for controlled atmosphere increases complexity
Solution Approach 1:
The system merges the vacuum chamber functionality with the atmosphere control system, using the same chamber to perform both pressure reduction for bubble removal and to provide the controlled atmosphere during wetting. This integration eliminates the need for separate atmosphere control equipment, reducing overall system complexity while maintaining high gas absorption efficiency
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 significantly reduces the number of bubble defects in vias and subsequent electroplating operations, enhancing the quality of metal fill and reducing queue times by efficiently displacing residual gases, thereby improving the robustness and reliability of semiconductor processing.
Implementation Method 1
The wetting agent may absorb over 98% of carbon dioxide residing in the plurality of features defined by the substrate
Implementation Method 2
A chamber pressure may be maintained below about 100 kPa
Implementation Method 3
pressurizing the processing chamber to about atmospheric conditions
Data Source
AI summary
Methods of wetting a semiconductor substrate may include forming a controlled atmosphere in a processing chamber housing the semiconductor substrate. The semiconductor substrate may define a plurality of features, which may include vias. The methods may include flowing a wetting agent into the processing chamber. A chamber pressure may be maintained below about 100 kPa. The methods may also include wetting the plurality of features defined in the substrate.