Spin Chuck Drying Nozzle Radial Movement
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Solution Overview
Problem
Conventional methods for drying semiconductor wafers consume a large amount of process liquids like IPA, which is disadvantageous in terms of cost and efficiency.
Innovation Solution
A substrate processing method and apparatus that uses a drying fluid with higher volatility than the process liquid, such as IPA, and an inert gas, where the supply positions are moved radially outward from the rotational center of the substrate, with the inert gas nozzle positioned closer to the center than the fluid nozzle, to efficiently dry the substrate while minimizing liquid consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods spray IPA liquid or vapor onto a rotating wafer for drying, then the wafer can be dried effectively, but a large amount of process liquid is consumed
Solution Approach 1:
The patent changes the physical state parameter of the drying agent from liquid IPA to gaseous nitrogen, and adjusts the volatility parameter by using a drying fluid with higher volatility than the process liquid. This parameter change reduces IPA consumption while maintaining drying effectiveness through the combined action of nitrogen gas and high-volatility drying fluid
Solution Approach 2:
The patent replaces the mechanical spraying system that delivers liquid IPA with a gas delivery system that supplies nitrogen gas. The inert gas flows across the wafer surface to facilitate drying, substituting the liquid-based mechanical spraying approach with a gas-based flow system that reduces liquid consumption
2Reliability
If IPA liquid is supplied to a rotating wafer for drying, then the substrate can be dried, but the processing time is extended
Solution Approach 1:
The patent implements periodic action by moving the nozzles radially outward during the drying step, creating a time-dependent delivery pattern. The inert gas and drying fluid are supplied in a sequence that progresses from inner to outer regions of the wafer, optimizing the drying process timing and reducing overall processing time while maintaining effectiveness
Solution Approach 2:
The patent applies preliminary action by positioning the inert gas supply nearer to the rotational center than the drying fluid supply, and by pre-positioning nozzles before the drying step begins. This preliminary arrangement of supply positions and the use of high-volatility drying fluid prepare the system for efficient drying, reducing the time required to achieve effective drying
3Manufacturing precision
If deionized water is supplied to a wafer while rotating, then cleaning is achieved, but water marks remain on the substrate surface after drying
Solution Approach 1:
The patent introduces nitrogen gas as an intermediary substance between the deionized water cleaning step and the final dried state. The inert gas flows across the wafer surface during drying, acting as a mediator that prevents direct contact between residual water and the wafer surface, thereby preventing water mark formation while maintaining cleaning quality
Solution Approach 2:
The patent creates an inert atmosphere using nitrogen gas during the drying step. This inert environment prevents oxidation and water mark formation on the wafer surface by displacing air and creating a controlled drying environment. The inert gas atmosphere allows water to evaporate without leaving marks, preserving the cleaning quality achieved by deionized water
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 reduces IPA consumption, shortens processing time, and effectively prevents water marks on the substrate surface by promoting efficient drying with nitrogen gas.
Implementation Method 1
the wafer is rotated to remove liquid droplets therefrom due to the centrifugal force
Implementation Method 2
supplying to the substrate a drying fluid having a higher volatility than that of the process liquid
Data Source
AI summary
A substrate processing apparatus according to the present invention is provided with a spin chuck (3) that holds a substrate (W) and rotates the same. A process liquid supply system (11, . . . ) is disposed to supply a process liquid to the substrate rotated by the spin chuck. There are disposed a fluid nozzle (12) that supplies to the substrate a drying fluid having a higher volatility than that of the process liquid, and an inert gas nozzle (13) that supplies an inert gas to the substrate. A nozzle moving mechanism (15, 52, . . . ) is disposed that moves the nozzles (12, 13) radially outward relative to a rotational center (Po) of the substrate, while maintaining the inert gas nozzle nearer to the rotational center of the substrate than the fluid nozzle.