Dual Nozzle Developer Spreading for Substrate Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor device fabrication, the existing developing methods struggle to achieve uniformity in the degree of progress of development across the substrate, leading to variations in line width and hole diameter due to non-uniform developer distribution caused by centrifugal force during the lithography process.
Innovation Solution
A developing method involving a rotatable substrate holding unit, where a first developer nozzle forms a puddle on the substrate and spreads it uniformly, followed by a second nozzle adjusting the developer distribution to underdeveloped areas, ensuring uniform development across the substrate surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a developer is supplied locally to a position onto a substrate rotating at a relatively high speed, then the developer spreads from the supplying position with the developer swirling or rotating on the substrate due to centrifugal force, but the concentration of the developer varies when the developer flows swirlingly, which prevents improvement of in-plane uniformity of the degree of progress of development
Solution Approach 1:
The developing apparatus divides the developer supply into two separate nozzles: a first developer nozzle that forms an initial puddle and a second developer nozzle that supplies additional developer to specific regions. This segmentation allows different zones of the substrate to receive tailored developer amounts, correcting the concentration non-uniformity that would otherwise occur with a single swirling flow from one nozzle.
Solution Approach 2:
The second developer nozzle is positioned to supply developer locally to regions where the degree of progress of development is insufficient. By adjusting the supply position and amount of developer in specific local areas, the system achieves uniform in-plane development progress while maintaining the benefits of centrifugal spreading.
2Device complexity
If a stationary developing method is used with a long nozzle extending parallel to the substrate surface, then the apparatus structure is simple, but the in-plane uniformity of line width and hole diameter of a pattern is poor
Solution Approach 1:
The system transitions from a stationary nozzle configuration to a dynamic setup where the substrate rotates and the developer nozzles can be positioned and moved dynamically. The first nozzle creates an initial puddle while the second nozzle dynamically supplies developer to compensate for non-uniformities, achieving both operational simplicity and high pattern uniformity.
3Productivity
If the developer is supplied onto the substrate with the substrate being rotated, then the developer spreads due to centrifugal force, but the concentration of the developer varies causing non-uniform development progress
Solution Approach 1:
The system uses a control unit that monitors the degree of progress of development and adjusts the supply conditions of the second developer nozzle accordingly. By providing feedback on development uniformity and adjusting developer supply in real-time, the system maintains both high development speed through centrifugal force and uniform in-plane development progress.
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 in-plane uniformity of the development process, enhancing the consistency of line width and hole diameter by uniformly distributing the developer, thereby addressing the non-uniformity issues in existing techniques.
Implementation Method 1
a method that moves a developer nozzle discharging a developer in a radial direction of the substrate with the substrate being rotated... the developer having been supplied onto the substrate flows to be agitated due to centrifugal force
Implementation Method 2
forming a puddle of a developer on a surface of the substrate held by the substrate holding unit, by discharging the developer from a discharging port of a first developer nozzle
Implementation Method 3
subsequently spreading the puddle of the developer over the whole surface of the substrate, by moving the first developer nozzle discharging the developer from one of a central part and a peripheral part to the other of the central part and the peripheral part of the rotating substrate
Implementation Method 4
a developer supplying step that supplies the developer from a second developer nozzle onto the surface of the substrate with the substrate being rotated, thereby to uniformize, in a plane of the substrate, distribution of a degree of progress of development
Implementation Method 5
a developer removing step that is performed between the developer spreading step and the developer supplying step to remove the developer on the surface of the substrate
Data Source
AI summary
A developing method includes: forming a puddle of a developer on a surface of the substrate held by the substrate holding unit by a first developer nozzle; subsequently spreading the puddle of the developer over the whole substrate surface, by moving the first developer nozzle discharging the developer from a central or peripheral part to the peripheral or central part of the rotating substrate, with a contacting part of the first developer nozzle contacting with the puddle; supplying the developer from a second developer nozzle onto the rotating substrate, thereby to uniformize, in the substrate plane, distribution of a degree of progress of development by the developer spreading step; and removing the developer between the developer spreading step and the developer supplying step to remove the developer on the substrate.