Substrate Processing Drain Layout for Silicon Crystal Clog Prevention
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in efficiently managing and preventing clogging of liquid drain lines due to the deposition of silicon-based crystals from etching liquids, which can lead to equipment blockages and processing inefficiencies.
Innovation Solution
The apparatus incorporates a liquid recovery unit and a separate liquid recovery unit drain line, along with a cleaning unit that uses dilute hydrofluoric acid to dissolve and remove silicon-based crystals from the liquid recovery unit and drain lines, and a gas purging unit to physically separate crystals, ensuring the liquid drain paths remain unclogged.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the processing liquid is drained into a shared drain line, then the device complexity is reduced, but the reliability deteriorates due to clogging from silicon-based crystal deposition
Solution Approach 1:
The patent divides the drain line system into two separate segments: a first drain line for draining processing liquid from the processing tub to the storage, and a second drain line for draining processing liquid from the liquid recovery unit to external disposal. This segmentation prevents silicon-based crystals from blocking the entire drainage system, as crystals tend to deposit in the second drain line while the first drain line remains clear.
Solution Approach 2:
The storage acts as an intermediary component between the processing tub and the external drain line. It temporarily holds processing liquid and allows crystals to settle and deposit in the storage or second drain line, preventing direct clogging of the primary drainage path from the processing tub.
2Loss of substance
If the liquid recovery unit is added to recover overflown liquid, then the loss of substance is reduced, but the device complexity increases
Solution Approach 1:
The liquid recovery unit recovers processing liquid that overflows from the processing tub during batch processing. Instead of discarding this liquid immediately, it is collected and can be reused, reducing the loss of expensive processing liquid while the separate drain line configuration manages the crystal deposition issue.
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 configuration effectively prevents clogging of the liquid drain lines, maintaining the apparatus's efficiency and extending its operational lifespan by ensuring continuous flow and preventing the accumulation of silicon-based crystals.
Implementation Method 1
a cleaning unit configured to dissolve the silicon-based crystals with dilute hydrofluoric acid
Implementation Method 2
a gas purging unit configured to separate the silicon-based crystals
Data Source
AI summary
A substrate processing apparatus includes a processing tub, a storage, a liquid recovery unit, a storage drain line and a liquid recovery unit drain line. The processing tub is allowed to accommodate therein multiple substrates, and configured to store therein a processing liquid. The storage is connected to the processing tub, and configured to store therein the processing liquid drained from the processing tub. The liquid recovery unit is configured to receive the processing liquid overflown from the processing tub. The storage drain line is configured to drain a liquid stored in the storage. The liquid recovery unit drain line is configured to drain a liquid received from the liquid recovery unit to an external drain line provided at an outside.