Supercritical Substrate Pressure Cycling to Prevent Pattern Collapse
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Solution Overview
Problem
In semiconductor device manufacturing, existing supercritical drying methods face challenges in maintaining the supercritical state of processing fluids during circulation processes, leading to inefficiencies and potential pattern collapse due to uneven fluid flow and pressure fluctuations.
Innovation Solution
A substrate processing apparatus that utilizes a control valve to adjust the pressure in a processing container, executing alternating pressure-lowering and pressure-raising steps within a specific range, ensuring the fluid remains in a supercritical state through a zigzag control method, preventing fluid stagnation and promoting uniform fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If pressure is maintained within a fixed range during circulation process, then supercritical state is maintained, but fluid stagnation occurs and processing efficiency decreases
Solution Approach 1:
The patent implements periodic pressure variations within the supercritical range by executing alternating pressure-raising and pressure-lowering steps. The controller adjusts the control valve to create cyclic pressure changes that prevent fluid stagnation while maintaining the supercritical state, thereby improving processing efficiency without compromising state stability.
Solution Approach 2:
The patent transitions from static pressure maintenance to dynamic pressure control by introducing controlled fluctuations. The system dynamically adjusts pressure between upper and lower limits within the supercritical range, creating fluid motion that enhances processing effectiveness while preserving the supercritical state through continuous monitoring and adjustment.
2Productivity
If pressure is frequently adjusted to prevent fluid stagnation, then fluid flow improves, but pressure stability decreases risking loss of supercritical state
Solution Approach 1:
The patent employs a feedback control mechanism where the controller continuously monitors pressure within the processing container and adjusts the control valve accordingly. When pressure approaches the upper limit during pressure-raising steps or the lower limit during pressure-lowering steps, the controller automatically reverses the pressure trend, ensuring pressure stability is maintained while achieving fluid motion through controlled fluctuations.
Solution Approach 2:
The patent utilizes controlled parameter changes by varying pressure within defined boundaries (between upper and lower limits) while maintaining the supercritical state. The controller adjusts pressure parameters dynamically, changing them in a controlled manner to prevent stagnation while ensuring they remain within the range that preserves the supercritical phase.
3Device complexity
If conventional pressure control is used, then system simplicity is maintained, but uneven fluid flow causes pattern collapse
Solution Approach 1:
The patent introduces periodic pressure-raising and pressure-lowering steps that create cyclic fluid motion within the processing container. This periodic action generates consistent fluid flow patterns that prevent localized stagnation and ensure uniform processing across the substrate surface, thereby preventing pattern collapse while adding minimal complexity through controller programming.
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 effectively maintains the supercritical state of the processing fluid, preventing pattern collapse and ensuring efficient drying of substrates by maintaining consistent fluid flow and pressure control, thereby enhancing the processing efficiency and substrate quality.
Implementation Method 1
a substrate processing apparatus of processing a substrate by using a processing fluid in a supercritical state
Implementation Method 2
a control valve interposed in the discharge line; and a controller configured to control a pressure in the processing container by adjusting an opening degree of the control valve
Data Source
AI summary
A substrate processing apparatus of processing a substrate by using a processing fluid in a supercritical state, the substrate processing apparatus includes: a processing container in which the substrate is accommodated; a supply line connecting the processing container to a fluid source configured to send out the processing fluid in the supercritical state; a discharge line configured to discharge the processing fluid from the processing container; a control valve interposed in the discharge line; and a controller configured to control a pressure in the processing container by adjusting an opening degree of the control valve. In a circulation process in which the processing fluid is supplied to the processing container from the supply line, the controller is configured to adjust the opening degree of the control valve such that each of a pressure-lowering step and a pressure-raising step.