Nanoparticle Detection via Interferometry and Ejection
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Solution Overview
Problem
Current technologies face challenges in detecting and removing nanoscale particles from surfaces due to strong electrostatic, chemical, and physical forces, which are difficult to overcome, especially in cleanroom environments where particles smaller than 20 nm can interfere with sensitive manufacturing processes.
Innovation Solution
The development of devices and methods that use a combination of electrostatic, chemical, physical, and magnetic forces to dislodge nanoscale particles from surfaces, utilizing a particle analyzer connected to a probe unit with an ejection system and vacuum system to collect and analyze particles, including condensation particle counters and split differential interferometric optical particle counters, which reduce the energy required for detection and enable handheld operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional scattered light optical particle counters are used to detect smaller particles, then detection sensitivity is improved, but energy consumption increases exponentially
Solution Approach 1:
The patent changes the detection parameter from direct scattered light measurement to measuring light interference patterns. By using split differential interferometry, the system detects particle-induced phase changes in light waves rather than relying on scattered light intensity, enabling detection of smaller particles with reduced laser power
Solution Approach 2:
The patent replaces the mechanical/optical scattering detection mechanism with an interferometric measurement system. Instead of measuring light scattered by particles, the system measures interference patterns created when particles pass through split light beams, achieving higher sensitivity with lower energy input
2Device complexity
If scattered light optical particle counters reduce laser power to decrease cost and size, then device cost and size are reduced, but detection capability for small particles deteriorates
Solution Approach 1:
The patent fundamentally changes the detection parameter from scattered light intensity to light interference phase differences. This parameter change allows the use of lower power lasers while maintaining or improving detection capability for small particles, as interferometric measurements are more sensitive to particle presence than scattered light measurements
3Manufacturing precision
If nanoscale particles are present on surfaces in cleanroom environments, then manufacturing process sensitivity is improved, but particle adhesion to surfaces increases due to electrostatic and chemical forces
Solution Approach 1:
The patent applies preliminary action by using the ejection system to dislodge particles from surfaces before they can adhere or before analysis occurs. The system proactively removes particles through electrostatic, mechanical, or thermal ejection mechanisms, preventing adhesion issues and enabling detection of particles that would otherwise be difficult to analyze
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
These devices effectively dislodge and detect nanoscale particles, providing sensitive and reliable characterization, reducing the risk of particle interference in cleanroom environments and enabling efficient cleaning and sampling of surfaces in microelectronic and pharmaceutical manufacturing.
Implementation Method 1
Significant forces may be required to dislodge or remove particles from a surface, including for nanoscale-sized particles (e.g., particles having an effective or average diameter less than 1 μm, less than 100 nm, or less than 20 nm). A combination of electrostatic, chemical, physical and magnetic forces may be responsible for causing nanoscale particles to adhere or stick to various surfaces
Implementation Method 2
A combination of electrostatic, chemical, physical and magnetic forces may be responsible for causing nanoscale particles to adhere or stick to various surfaces
Implementation Method 3
a vacuum system operably connected to the sampling port such that the vacuum system is configured to force dislodged particles proximate to the sample probe through the sampling port, along the flow path and into the particle counter
Implementation Method 4
condensation particle counters increase the perceived diameter of the particles being analyzed by condensing a vapor into a liquid on the particles' surface
Implementation Method 5
condensing a vapor into a liquid on the particles' surface, increasing the apparent volume of the particle
Implementation Method 6
split differential interferometric detectors manipulate the laser source into two beams and use interferometry to analyze the interaction of the two beams
Data Source
AI summary
Provided herein is a particle analyzer that is operably connected to a probe unit that is capable of both dislodging particles from a surface and sampling the particles after they have been dislodged. The devices and methods described herein may be lightweight and/or handheld, for example, so that they may be used within a cleanroom environment to clean and sample permanent surfaces and tools. The devices may include optical particle counters that use scattered, obscured or emitted light to detect particles, including condensation particle counting systems or split detection optical particle counters to increase the sensitivity of the device and thereby facilitate detection of smaller particles, while avoiding the increased complexity typically required for the detection of nanoscale particles, such as particles less than 100 nm in effective diameter.