Composite Wafer Cleaning With Laser and Reactive Fluid Steps
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Solution Overview
Problem
Conventional cleaning techniques for semiconductor wafers, such as the RCA standard clean method, fail to meet the increasingly stringent cleanliness requirements of nano-processing environments, leading to process yield issues and high water consumption with hazardous waste emissions, while ozone-deionized water techniques are limited by unstable efficiency due to environmental variables.
Innovation Solution
A composite cleaning process utilizing a combination of laser reactive cleaning and gas or liquid reactive cleaning, including ozone cleaning, hydrofluoric acid cleaning, and RCA cleaning agents, to enhance cleaning efficacy and reduce water consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional RCA cleaning method is used, then cleaning process is well-established and reliable, but water consumption is high and hazardous waste emissions increase
Solution Approach 1:
The patent replaces the chemical-mechanical RCA cleaning system with a laser-based cleaning system. The laser cleaning device uses optical energy to remove contaminants through ablation, photochemical reactions, and plasma generation, eliminating the need for large volumes of chemical solutions and water rinsing, thereby reducing water consumption and hazardous waste emissions while maintaining cleaning reliability
Solution Approach 2:
The patent changes the fundamental cleaning parameter from chemical concentration and temperature to laser power, pulse duration, and scanning speed. By adjusting these laser parameters, the system achieves effective contaminant removal without requiring extensive water rinsing and chemical waste treatment processes
2Object-affected harmful factors
If ozone-deionized water technique is used, then environmental impact is reduced, but cleaning efficiency becomes unstable due to environmental variables
Solution Approach 1:
The patent replaces the ozone-deionized water cleaning system with a laser cleaning system. The laser cleaning device uses optical energy to directly ablate and decompose contaminants through photochemical reactions and plasma generation, eliminating dependence on environmental variables such as temperature, pH, and ozone concentration that affect water-based cleaning efficiency
Solution Approach 2:
The patent employs pulsed laser operation with controlled pulse duration and repetition frequency. This periodic action allows precise control of energy delivery to the contaminant-laden surface, ensuring consistent cleaning performance by delivering energy in controlled bursts rather than continuous exposure, thereby improving reliability
3Manufacturing precision
If multiple cleaning steps are performed, then cleaning thoroughness is improved, but process time increases and productivity decreases
Solution Approach 1:
The patent combines multiple cleaning functions into a single laser cleaning step. The laser cleaning device simultaneously performs organic contaminant removal, inorganic particle elimination, oxide layer reduction, and surface activation through different laser parameter settings or multi-wavelength lasers, replacing the sequential RCA, ozone, and rinsing steps with one integrated process
Solution Approach 2:
The patent designs the laser cleaning system to handle multiple contaminant types with a single device. By adjusting laser parameters such as wavelength, power, and pulse duration, the same laser cleaning device can effectively remove organic residues, inorganic particles, metal contaminants, and oxide layers, providing universal cleaning capability that maintains thoroughness while improving productivity
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 composite cleaning process effectively removes contaminants like organic matters, polymers, and metal impurities, reduces process steps and chemical usage, and improves surface roughness, meeting stringent cleanliness requirements while minimizing environmental impact.
Implementation Method 1
a laser cleaning device is used to perform a laser reactive cleaning step
Implementation Method 2
using a gas or liquid cleaning device to perform a gas or liquid reactive cleaning step... including ozone cleaning
Implementation Method 3
including ozone cleaning, hydrofluoric acid cleaning
Data Source
AI summary
Disclosed are a composite cleaning process and a composite cleaning system used for performing the composite cleaning process. The composite cleaning system comprises a carrier, a laser cleaning device, and a gas or liquid cleaning device. The carrier is used to carry at least one object, and the object has at least one to-be-cleaned target located on a to-be-cleaned area of the object. A composite cleaning step of the composite cleaning process comprises using the laser cleaning device to perform a laser reactive cleaning step on the to-be-cleaned area of the object and using the gas or liquid cleaning device to perform a gas or liquid reactive cleaning step on the to-be-cleaned area of the object. Thereby, either the laser reactive cleaning step or the gas or liquid reactive cleaning step is assisted by the other to improve a cleaning effect of the to-be-cleaned target.