Wafer Baking Device with Diffusion Element and Evacuation Ring
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Solution Overview
Problem
Existing semiconductor manufacturing processes face challenges in achieving uniform solvent evaporation and preventing condensation during the baking of wafers coated with solvents, leading to potential coating disturbances and damage.
Innovation Solution
A baking device with a diffusion element for even purge gas distribution above the wafer and a radially arranged evacuation ring at the chamber ceiling, ensuring a uniform solvent concentration and preventing condensation by establishing a downward and outward purge gas flow, combined with additional purge gas entrances and a heating system to minimize solvent concentration at the ceiling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If solvent is removed from the chamber during softbaking, then condensation is avoided, but uniform solvent concentration above the wafer becomes difficult to maintain
Solution Approach 1:
The inlet is divided into multiple inlet openings distributed over the surface of the diffusion element, allowing purge gas to be admitted evenly across the entire wafer surface rather than from a single location, thereby maintaining uniform solvent concentration while preventing condensation
Solution Approach 2:
A diffusion element is introduced as an intermediary component between the purge gas source and the wafer chamber. This diffusion element with multiple inlet openings evenly distributes the purge gas flow, enabling uniform solvent concentration maintenance while effectively removing solvent to prevent condensation
2Object-affected harmful factors
If purge gas flow is increased to remove solvent, then condensation is prevented, but solvent concentration uniformity above the wafer deteriorates
Solution Approach 1:
The diffusion element provides locally optimized purge gas distribution at multiple points across the wafer surface. Each inlet opening delivers purge gas to a specific local region, ensuring uniform solvent removal and concentration maintenance across different areas of the wafer simultaneously
Solution Approach 2:
The multiple inlet openings arranged on the diffusion element create equipotential purge gas distribution across the wafer surface. This ensures that all regions of the wafer experience similar purge gas flow conditions, maintaining uniform solvent concentration throughout the chamber
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
The solution ensures uniform solvent evaporation and prevents condensation, maintaining coating uniformity and avoiding damage by maintaining a homogeneous solvent concentration and flow path, thus ensuring consistent coating properties post-baking.
Implementation Method 1
the inlet is formed as a diffusion element arranged above the wafer so as to admit the purge gas evenly over substantially the entire surface of the wafer
Implementation Method 2
the wafer with the coating is pre-baked or softbaked to remove excess solvent from the coating
Implementation Method 3
the wafer can be exposed to temperatures of 90 to 100° C. for 30 to 60 seconds while being placed on a heated support
Implementation Method 4
a purge gas flow is established which is first generally downwardly and radially outwardly and then upwardly towards the evacuation
Data Source
AI summary
A baking device for a wafer coated with a coating containing a solvent is described, having a baking chamber, a support for the wafer, an inlet for a purge gas, and an evacuation for the purge gas charged with solvent evaporated from the coating. The inlet is formed as a diffusion element arranged above the wafer so as to admit the purge gas evenly over substantially the entire surface of the wafer, and the evacuation is formed as an evacuation ring which radially surrounds the diffusion element and is arranged at a ceiling of the baking chamber.