Substrate Pre-Wetting and Spin Control for Temperature Uniformity
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Solution Overview
Problem
In semiconductor manufacturing, existing substrate processing methods face challenges in achieving uniform temperature distribution across the substrate during liquid processing, leading to inefficiencies in chemical liquid processing and increased consumption of expensive chemicals.
Innovation Solution
A substrate processing method involving pre-wetting and main processing steps, where a substrate is heated, a liquid film of pre-wetting liquid is formed on its surface, and then processed with a chemical liquid while controlling the rotational speed and temperature adjustment using heated and room-temperature DIW, reducing the temperature of the substrate to maintain uniformity and minimize chemical liquid consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heated chemical liquid is supplied to the center of a rotating substrate, then the substrate temperature can be increased, but the temperature distribution across the substrate becomes non-uniform with the peripheral edge being cooler
Solution Approach 1:
The substrate processing is divided into distinct stages: pre-heating stage (high rotational speed with heated liquid), processing stage (lower rotational speed with chemical liquid), and cooling stage (room temperature liquid). This temporal and functional segmentation allows each stage to optimize for its specific purpose, achieving both temperature increase and uniformity.
Solution Approach 2:
The substrate is pre-heated to a higher temperature before the main chemical processing step. This preliminary heating ensures that when the chemical liquid is applied, the substrate maintains sufficient temperature for effective processing, and the temperature uniformity is better controlled throughout the subsequent steps.
2Manufacturing precision
If the substrate rotational speed is increased to improve temperature uniformity, then chemical liquid processing efficiency decreases
Solution Approach 1:
The substrate rotation speed is varied periodically across different processing stages: high speed during pre-heating, reduced speed during chemical processing, and adjusted speed during cooling. This periodic variation optimizes both temperature uniformity and processing efficiency at different times in the cycle.
Solution Approach 2:
The rotational speed is made dynamic rather than constant, allowing it to be adjusted according to the specific processing requirements of each stage. The system transitions smoothly between different rotational speeds to match the operational needs of heating, processing, and cooling phases.
3Temperature
If heated chemical liquid is supplied continuously, then substrate temperature is maintained, but chemical liquid consumption increases
Solution Approach 1:
The substrate is pre-heated using heated liquid before the main chemical processing step. This preliminary heating reduces the temperature demand during the subsequent chemical processing, allowing the chemical liquid to be applied at or near room temperature, thereby reducing chemical liquid consumption while maintaining effective processing.
Solution Approach 2:
The system uses room temperature or cooler liquid for the main processing step instead of continuously supplying heated chemical liquid. This approach treats the heating function as a separate, preliminary step using inexpensive heated liquid, while the main processing uses the actual chemical liquid more efficiently at lower temperatures.
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 enhances in-plane uniformity of the substrate temperature, reduces chemical liquid consumption, and lowers processing costs by optimizing the use of temperature adjustment fluids during substrate processing.
Implementation Method 1
increasing a temperature of a substrate by heating the substrate
Implementation Method 2
decreasing the temperature of the substrate
Implementation Method 3
heating and rotating the substrate at a first rotational speed
Data Source
AI summary
A substrate processing method includes: increasing a temperature of a substrate by heating the substrate; after the increasing the temperature of the substrate, forming a liquid film of a pre-wetting liquid on a first surface of the substrate by supplying the pre-wetting liquid to the first surface of the substrate while heating and rotating the substrate at a first rotational speed; after the forming the liquid film, processing the first surface of the substrate with a chemical liquid by supplying the chemical liquid to the first surface of the substrate while heating and rotating the substrate at a second rotational speed that is lower than the second rotational speed; and after the processing the first surface of the substrate, decreasing the temperature of the substrate.