Wafer Developing Apparatus With Semipermeable Diaphragm
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Solution Overview
Problem
Conventional developing apparatuses in photolithography suffer from liquid drops forming on the wafer surface due to rebounded developer mist, leading to contamination and defects in the photoresist patterns.
Innovation Solution
A developing apparatus with a semipermeable diaphragm that separates the housing into upper and lower chambers, allowing moisture to pass through while preventing larger liquid drops from falling back onto the wafer, utilizing a semipermeable material like polypropylene to manage moisture transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If continuous spray development is used to improve development speed, then development speed is improved, but liquid drops rebound from the wafer surface and fall onto the wafer, causing contamination
Solution Approach 1:
The housing is segmented into an upper chamber and a lower chamber by a semipermeable diaphragm. The upper chamber captures rebounded liquid drops and moisture, preventing them from falling onto the wafer in the lower chamber. This segmentation resolves the contradiction by maintaining the spray development process while isolating the contamination harm.
Solution Approach 2:
A semipermeable diaphragm is introduced as an intermediary component between the spray nozzle and the wafer surface. This diaphragm allows moisture vapor to pass through while blocking liquid drops, serving as a mediator that permits necessary moisture transfer while preventing harmful liquid drop contamination.
2Object-affected harmful factors
If a semipermeable diaphragm is added to prevent liquid drops from falling onto the wafer, then contamination is reduced, but the device complexity increases
Solution Approach 1:
A semipermeable diaphragm, which is a thin film structure, is used to separate the upper and lower chambers. This thin film approach prevents liquid drops while allowing moisture vapor passage, achieving contamination prevention with minimal structural complexity compared to rigid barriers.
Solution Approach 2:
The semipermeable diaphragm utilizes porous or microporous material properties to selectively allow moisture vapor molecules to pass through while blocking larger liquid drop particles. This material-based solution provides effective contamination prevention without requiring complex mechanical structures.
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
Effectively prevents liquid drops from forming on the wafer, reducing contamination and enhancing the yield of semiconductor dice by maintaining the integrity of the photoresist patterns.
Implementation Method 1
a semipermeable diaphragm disposed within the housing and separating the housing into an upper housing defining an upper chamber and a lower housing defining a low chamber, wherein the semipermeable diaphragm is semipermeable to moisture such that moisture is allowed to move from the lower chamber to the upper chamber, but liquid drops formed from the moisture are prohibited to move from the upper chamber to the lower chamber
Data Source
AI summary
The present application relates to a developing apparatus. The developing apparatus comprises a housing; a wafer support disposed within the housing and for holding a wafer; a semipermeable diaphragm disposed within the housing and separating the housing into an upper housing defining an upper chamber and a lower housing defining a low chamber, wherein the semipermeable diaphragm is semipermeable to moisture such that moisture is allowed to move from the lower chamber to the upper chamber, but liquid drops are prohibited to move from the upper chamber to the lower chamber; and a nozzle assembly disposed above the wafer support and for spraying at least developer to the wafer support.