Wafer Spin Cleaning Structure for Backside Liquid Retention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing spin cleaning machines for semiconductor processes are unable to effectively clean the back surface of wafers due to the inability of the cleaning liquid to stay on the surface for a long duration.
Innovation Solution
A wet processing apparatus is designed with a stage, support pins, a rotation driving unit, and a supply nozzle, along with a holding ring that surrounds the support pins to retain the cleaning liquid on both surfaces of the wafer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If a spin cleaning machine uses surface tension to hold cleaning liquid on the wafer, then the cleaning liquid can stay on the upper surface efficiently, but the cleaning liquid cannot stay on the back surface for a long duration
Solution Approach 1:
A holding ring is introduced as an intermediary component between the wafer back surface and the stage. This holding ring creates a confined space that acts as a mediator to retain the cleaning liquid on the back surface, preventing it from falling away and extending its contact time with the wafer back surface for effective cleaning.
Solution Approach 2:
The invention transitions from only cleaning the upper surface (one dimension) to cleaning both upper and lower surfaces (two dimensions) by introducing the holding ring structure. This allows the cleaning liquid to be retained and applied to the back surface, effectively adding another dimension to the cleaning process.
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 allows for efficient cleaning of both surfaces of the wafer, extending the holding time of the cleaning liquid and improving the overall cleaning process.
Implementation Method 1
the cleaning liquid stays on the upper surface (top surface) of the wafer due to the surface tension
Data Source
AI summary
A wet processing apparatus capable of carrying out a wet process efficiently for both the surfaces of a workpiece is provided. The wet processing apparatus comprises: a stage (19); a plurality of support pins (20a, 20b) protruding upward from the stage (19), respectively, and supporting an outer edge of a workpiece (W) at positions spaced from each other in a circumferential direction; a rotation driving unit for rotating the stage (19) about a rotation axis extending in a vertical direction; a supply nozzle (22) for supplying a process liquid to the workpiece (W) supported by the plurality of support pins (20a, 20b) from above the workpiece (W); and a holding ring (29) placed on the stage (19) so as to surround the plurality of support pins (20a, 20b) below the workpiece (W).