Multiple Wafer Single Bath Etcher With Isolated Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of porous silicon using a single wafer in a bath is limited by non-uniformity and etching speed, leading to inconsistent material quality due to varying etch characteristics across the wafer surface.
Innovation Solution
A multiple wafer single bath etcher system is designed with multiple blades to hold wafers, creating isolated etch cells for uniform etchant exposure, using seals and vacuum to secure wafers, and incorporating a sparger for bubble removal and etchant circulation, along with temperature control and adjustable agitation to enhance etching uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single wafer is etched in a bath, then the etching process is simple to operate, but the etching uniformity and speed are limited
Solution Approach 1:
The patent divides the single bath into multiple isolated etch cells using vertical blades with seals, allowing each cell to independently process a wafer. This segmentation enables uniform etching across multiple wafers simultaneously while maintaining controlled conditions in each cell, resolving the contradiction between etching uniformity and device complexity.
2Productivity
If a single wafer is etched in a bath, then the equipment is simple, but the etching speed is limited
Solution Approach 1:
The patent combines multiple etching operations into a single bath by creating multiple isolated etch cells within one bath container. This allows simultaneous processing of multiple wafers in parallel, significantly increasing productivity while keeping the overall equipment structure relatively simple compared to using multiple separate baths.
3Productivity
If multiple wafers are etched simultaneously, then productivity increases, but etchant circulation and uniformity become more difficult to maintain
Solution Approach 1:
The patent segments the bath into isolated etch cells using blades with seals at the bottom and sides. Each cell independently processes one wafer with dedicated etchant circulation, ensuring uniform etching characteristics across all wafers while enabling simultaneous processing of multiple wafers, thus resolving the contradiction between productivity and etch consistency.
Solution Approach 2:
The patent introduces spargers as intermediary devices that provide dedicated etchant circulation and bubble removal in each isolated etch cell. These spargers act as mediators to maintain uniform etching conditions in each cell, ensuring consistent etch characteristics across multiple wafers processed simultaneously.
4Manufacturing precision
If multiple wafers are etched in isolated cells, then etching uniformity improves, but device complexity increases
Solution Approach 1:
The patent uses vertical blades with integrated seals to segment the bath into isolated etch cells. Each blade with its seal system creates an independent processing environment, ensuring consistent porous silicon production across multiple wafers. The modular blade design allows the system to achieve high manufacturing precision while keeping the added complexity manageable through standardized components.
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 system allows for simultaneous etching of multiple wafers with improved uniformity and consistency of porous silicon production, maintaining etchant chemistry and optimizing etching conditions for enhanced material quality.
Implementation Method 1
The seals between the wafer and blade have a vacuum enabling holding the wafer firmly to the blade during etching
Implementation Method 2
Between the blades in each isolated etch cell, etchant is circulated to keep uniform exposure of etchant on wafer surface (e.g., to remove bubbles, keep etchant refreshed, etc.)
Data Source
AI summary
An etcher comprises a bath, a plurality of blades, and a tunnel. The bath includes a first electrode at a first end and a second electrode at a second end. The plurality of blades is configured to fit in the bath. At least one blade of the plurality of blades holds a wafer. At least one tunnel is configured to fit between adjacent blades of the plurality of blades in the bath.