CMP Wafer Inspection with Buffer Region Detector
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Solution Overview
Problem
Current chemical mechanical polishing processes lack a detector to inspect wafer surfaces for peeling phenomena and defects, leading to inefficient and imprecise manual detection, which can contaminate and damage the apparatus and result in wasted costs and decreased yield.
Innovation Solution
A chemical mechanical polishing apparatus with a buffer region equipped with an optical detector, including a laser and infrared detector, that performs pre- and post-polishing inspections, and a controller-activated cleaning process using deionized water or chemicals to address surface abnormalities before proceeding with polishing, preventing contamination and ensuring complete material removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual detection is used to inspect wafer surface, then detection can be performed without additional equipment, but detection efficiency is low and precision is poor
Solution Approach 1:
The patent replaces manual mechanical inspection with an optical detection system that uses light sources and sensors to automatically detect wafer surface conditions, including peeling phenomena and defects, thereby improving both precision and efficiency simultaneously
Solution Approach 2:
The detection system is integrated into the polishing apparatus itself, allowing the machine to automatically inspect wafers before and after polishing without requiring separate manual inspection steps, thus improving productivity while maintaining high precision
2Productivity
If wafer with peeling surface is processed in chemical mechanical polishing apparatus, then polishing process can proceed, but apparatus contamination and damage occur
Solution Approach 1:
The patent performs pre-polishing detection to identify wafers with peeling surfaces before they enter the polishing apparatus. Defective wafers are detected and removed from the process flow in advance, preventing contamination and damage to the polishing equipment while maintaining continuous processing of good wafers
Solution Approach 2:
The optical detection system acts as an intermediary between wafer preparation and polishing processes, screening out defective wafers before they can cause harm to the polishing apparatus, thus protecting the equipment while allowing uninterrupted processing of acceptable wafers
3Reliability
If no detector is assembled on chemical mechanical polishing apparatus, then apparatus structure remains simple, but wafer surface condition cannot be inspected
Solution Approach 1:
The patent integrates optical detection components into the existing polishing apparatus structure, allowing the same equipment to perform both polishing and inspection functions. This multi-functionality approach adds detection capability without significantly increasing overall device complexity
Solution Approach 2:
The detection system is merged with the polishing apparatus by positioning light sources and sensors within the existing machine structure, combining inspection and polishing functions in one integrated system rather than using separate standalone devices
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
The solution enables precise inspection and prevention of wafer surface defects, preventing apparatus contamination, reducing costs, and increasing process efficiency and yield by ensuring only defect-free wafers enter the polishing process.
Implementation Method 1
the detector includes an optical detector
Implementation Method 2
the optical detector includes a laser detector
Implementation Method 3
the optical detector includes an infrared detector
Implementation Method 4
The cleaning process includes a step of spraying deionized water, gas or chemical reagent
Data Source
AI summary
The invention is directed to a chemical mechanical polishing process. The chemical mechanical polishing process comprises steps of providing a wafer disposed at a wafer handling region of a chemical mechanical polishing apparatus and then moving the wafer into a buffer region of the chemical mechanical polishing apparatus. A first detecting process is performed for obtaining a pre-polishing condition of the wafer by using a detector in the buffer region and the wafer is moved into a chemical mechanical polishing region and performing a chemical mechanical process. A second detecting process is performed, in the buffer region, for obtaining a post-polishing condition of the wafer by using the detector of the buffer region.