Phosphoric Acid Substrate Drying to Prevent 3D Pattern Collapse
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fine three-dimensional structures on substrates collapse during collective drying processing in batch-type processing apparatuses, as the drying process can cause evaporation of phosphoric acid, leading to structural damage.
Innovation Solution
A substrate processing method involving a phosphoric acid processing step, followed by a coarse rinse processing step where phosphoric acid is partially replaced with a rinse liquid, and then a single-substrate drying processing step, with temperature control and steam exposure to minimize evaporation and adhesion, ensuring the phosphoric acid remains in patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If collective drying processing is performed on multiple substrates, then processing throughput is improved, but three-dimensional structures on substrates collapse
Solution Approach 1:
The drying process is segmented into two distinct stages: (1) collective coarse drying of multiple substrates to remove excess liquid, and (2) individual precise drying of each substrate to prevent structure collapse. This segmentation allows the system to achieve both high throughput and high precision by applying different drying strategies to different subsets of substrates at different times.
Solution Approach 2:
Before performing the final individual drying that prevents collapse, the system first performs a preliminary collective drying step that removes the majority of liquid from multiple substrates. This preliminary action reduces the liquid load on subsequent individual drying steps, enabling them to complete the process without causing structure collapse while maintaining high throughput.
2Loss of time
If rapid cooling is applied after phosphoric acid processing, then processing time is reduced, but substrate damage increases
Solution Approach 1:
The system introduces a temperature-controlled rinse liquid as an intermediary medium between the hot phosphoric acid processing step and the final cooling stage. The rinse liquid is maintained at a controlled temperature that prevents rapid thermal shock to the substrate, thereby reducing substrate damage while still enabling efficient heat transfer and reasonable processing time.
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 effectively suppresses the collapse of three-dimensional structures by maintaining phosphoric acid in patterns, reducing substrate damage from rapid cooling and evaporation, and minimizing liquid adhesion to transfer apparatuses.
Implementation Method 1
a batch-type processing apparatus has been proposed that etches and removes a silicon nitride film by using phosphoric acid
Implementation Method 2
the processing apparatus performs rinse processing for replacing phosphoric acid adhered to the plurality of substrates with a rinse liquid
Implementation Method 3
the plurality of substrates are exposed to an atmosphere of steam of a second rinse liquid having latent heat of vaporization lower than that of the first rinse liquid
Data Source
AI summary
A substrate processing method includes a phosphoric acid processing step, a coarse rinse processing step, and a single-substrate drying processing step. In the phosphoric acid processing step, a plurality of substrates are immersed in phosphoric acid inside a processing tank. In the coarse rinse processing step, after the phosphoric acid processing step, a part of the phosphoric acid adhering to the plurality of substrates is replaced with a first rinse liquid to an extent that the phosphoric acid remains in patterns of the plurality of substrates. In the single-substrate drying processing step, the plurality of substrates are dried one by one after the coarse rinse processing step.