Wafer Defect Area Evaluation After Oxide Film Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for evaluating reactive ion etching (RIE) defect areas on wafers are complex, require expensive equipment, and struggle with process complexity and increased analysis time, particularly in distinguishing the boundary between O-band and VDP areas.
Innovation Solution
A method involving mirror-polishing, heat-treating, cleaning to remove oxide films, and polishing the wafer to accurately evaluate defects, using particle-counters or MAGICS to classify oxygen precipitate sizes and densities, defining RIE areas based on consecutive points with high oxygen precipitate density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the copper haze method or milk haze method is used to evaluate RIE defect areas, then the evaluation can be performed, but the process becomes complex and analysis time increases
Solution Approach 1:
The patent extracts and removes oxide films from the wafer surface through chemical cleaning before evaluation. This extraction of interfering substances (oxide films) simplifies the evaluation process by eliminating the need for complex haze methods, allowing direct observation and measurement of defect areas without additional process complexity
Solution Approach 2:
The patent performs preliminary heat treatment and oxide film removal before the actual defect evaluation. By conducting these preparatory actions in advance, the wafer surface is properly prepared for straightforward evaluation, eliminating the need for complex analysis procedures during the measurement phase
2Measurement precision
If the copper haze method or milk haze method is used to evaluate RIE defect areas, then the evaluation can be performed, but analysis time increases
Solution Approach 1:
By extracting and removing oxide films through chemical cleaning, the patent eliminates the need for time-consuming haze evaluation methods. The direct evaluation of cleaned surfaces significantly reduces analysis time while maintaining measurement precision
Solution Approach 2:
Preliminary heat treatment and cleaning are performed to prepare the wafer surface in advance. This preliminary action ensures that the actual evaluation can be completed quickly without requiring complex real-time analysis procedures, thereby reducing overall analysis time
3Measurement precision
If existing methods are used to distinguish O-band and VDP areas, then the boundary can be identified, but the process is complex and costly
Solution Approach 1:
The patent extracts oxide films that interfere with boundary identification. By removing these interfering layers through chemical cleaning, the underlying defect areas (O-band and VDP) become directly visible and distinguishable, eliminating the need for expensive and complex haze evaluation equipment
Solution Approach 2:
The patent uses simple, inexpensive chemical cleaning solutions instead of expensive specialized evaluation equipment. The chemical cleaners are consumable materials that provide effective boundary identification without requiring costly apparatus, making the process both simpler and more affordable
4Measurement precision
If RIE apparatus is used to evaluate RIE defect area, then accurate evaluation can be performed, but the equipment cost is high
Solution Approach 1:
The patent replaces expensive RIE apparatus with inexpensive chemical cleaning solutions and simple evaluation methods. The chemical cleaners are low-cost consumables that achieve accurate defect area evaluation without requiring costly equipment investment
Solution Approach 2:
By extracting oxide films through chemical cleaning, the patent enables accurate defect evaluation using simple, low-cost methods. The removal of interfering substances allows direct observation and measurement that does not require expensive specialized equipment
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
Accurately identifies and distinguishes RIE defect areas by excluding process-induced defects, providing precise boundaries between O-band and VDP areas, reducing complexity and cost through efficient evaluation techniques.
Implementation Method 1
heat-treating the wafer
Implementation Method 2
an oxide film formed during the heat-treating
Implementation Method 3
cleaning the wafer to remove an oxide film formed during the heat-treating
Implementation Method 4
mirror-polishing, heat-treating, cleaning to remove oxide films, and polishing the wafer
Implementation Method 5
using particle-counters or MAGICS to classify oxygen precipitate sizes and densities
Data Source
AI summary
A method of evaluating a defect area on a wafer, the method including preparing a mirror-polished wafer, heat-treating the wafer, cleaning the wafer to remove an oxide film formed during the heat-treating, polishing the wafer, and evaluating a defect on a surface of the wafer, is disclosed.