Double-Sided Wafer Polishing pH Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current double-sided polishing methods for semiconductor wafers result in significant edge waste and excessive consumption of polishing agents, with fluctuations in pH levels leading to inefficient polishing and cloth vitrification.
Innovation Solution
A method involving a double-side polishing machine where the pH value of the polishing agent is tightly regulated between 11.4 and 12.4, with a deviation of no more than ±0.2, using a basic composition to maintain this range, thereby preventing colloidal component coagulation and stabilizing the polishing agent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional double-sided polishing is used, then polishing can be performed efficiently, but edge waste is significant and polishing agent consumption is excessive
Solution Approach 1:
The patent applies parameter changes by precisely controlling the pH value of the polishing agent within the range of 11.4 to 12.4. This chemical parameter optimization prevents colloidal component coagulation, maintains polishing agent stability, and improves edge geometry while reducing material waste and agent consumption during the polishing process
2Productivity
If pH value of polishing agent is not controlled, then polishing can proceed, but polishing becomes inefficient and cloth glazing occurs
Solution Approach 1:
The patent implements feedback control by continuously monitoring and regulating the pH value of the polishing agent. A pH control system adjusts the polishing agent composition in real-time to maintain the optimal pH range of 11.4 to 12.4, preventing cloth glazing and ensuring consistent polishing quality throughout the process
Solution Approach 2:
The patent uses parameter changes by maintaining the pH value within the specific range of 11.4 to 12.4. This chemical parameter control prevents colloidal component coagulation, maintains polishing agent stability, and prevents cloth glazing, thereby ensuring reliable polishing performance
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 approach significantly reduces edge waste, increases the removal rate, and extends the service life of the polishing agent, enhancing the overall efficiency and economics of the polishing process by maintaining a stable polishing environment.
Implementation Method 1
regulating the pH value of the polishing agent; a target value for the pH value is not less than 11.4 and not more than 12.4 and the regulation of the pH value is carried out by temporarily supplying a basic composition to the polishing agent
Implementation Method 2
Polishing is one of the surface treatment processes. Various methods for polishing semiconductor wafers are known in the art. These include single-sided and double-sided polishing processes
Implementation Method 3
The polishing plates are each covered with a polishing cloth. The disk made of semiconductor material is arranged in the carrier plate between the polishing plates so that the front and back of the disk are in sliding contact with the polishing cloths
Data Source
Figure 1~2
Figure 3~4
AI summary
A method for double-sided polishing of at least one semiconductor material disc, comprising the following steps: placing the at least one semiconductor material disc in at least one rotor disc between an upper and a lower polishing plate of a double-sided polishing machine, wherein the underside of the upper polishing plate and the top of the lower polishing plate are each covered with a polishing cloth; setting the at least one rotor disc, the upper polishing plate, and the lower polishing plate into rotation; circulating a polishing compound between a collection container and the at least one semiconductor material disc arranged between the upper and lower polishing plates of the double-sided polishing machine; measuring the pH value of the polishing compound; and controlling the pH value of the polishing compound.wherein a target value for the pH value is not less than 11.4 and not more than 12.4 and the pH value is regulated by temporarily adding a basic composition to the polishing compound depending on the measured pH value such that the deviation of the measured pH value from the target pH value during the circulation of the polishing compound between the collection container and the at least one disk made of semiconductor material arranged between the upper and lower polishing plates of the double-sided polishing machine does not exceed ±0.2 at any time.