Acoustic Powder Feed Rate Sensor for Semiconductor Deposition
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Solution Overview
Problem
Existing methods for measuring powder feed rate in semiconductor deposition processes lack accuracy and ease of setup in production environments, particularly in achieving uniform film thickness and avoiding pulsing issues.
Innovation Solution
A powder feed rate sensor with an in-situ setup that generates acoustic vibration pulses upon powder impact, using sensors like pressure transducers or piezoelectric sensors to convert these pulses into electrical signals for precise measurement, and incorporates a feedback control module for real-time adjustment of the powder feed rate, potentially including a diaphragm or parallel plate capacitor for enhanced accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If loss-in-weight method is used to measure powder feed rate, then measurement can be performed, but accurate measurement with easy in-situ setup is not achieved
Solution Approach 1:
The patent replaces the mechanical loss-in-weight measurement system with an acoustic sensing system. Powder particles impacting a diaphragm generate acoustic signals that are detected and converted to electrical signals, eliminating the need for complex mechanical weighing equipment while enabling accurate feed rate measurement with simpler in-situ setup.
Solution Approach 2:
The patent introduces a diaphragm as an intermediary element between the powder stream and the sensor. The diaphragm converts the kinetic energy of impacting powder particles into acoustic vibrations, which are then detected by the sensor. This intermediary enables accurate measurement while maintaining ease of setup.
2Manufacturing precision
If powder feed rate is not accurately controlled, then deposition process can proceed, but uniform film thickness cannot be achieved
Solution Approach 1:
The patent implements a feedback control system where the acoustic sensor continuously monitors powder feed rate and the controller adjusts the powder feed accordingly. This closed-loop feedback ensures accurate control of powder delivery, enabling uniform film thickness deposition while compensating for variations in real-time.
3Stability of the object's composition
If vibratory feeders are used to avoid pulsing, then feeding can be performed, but precise feed rate measurement and control is difficult
Solution Approach 1:
The patent replaces mechanical vibratory feeders with an acoustic-based measurement and control system. By using acoustic signals from powder impact on a diaphragm, the system achieves precise feed rate measurement and control without relying on mechanical vibration mechanisms, thereby eliminating pulsing while maintaining measurement accuracy.
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
Enables accurate and real-time monitoring of powder flow, ensuring uniform semiconductor film deposition with improved precision and ease of setup, capable of operating in vacuum conditions for various manufacturing processes.
Implementation Method 1
a diaphragm, which, when powder is directed onto the diaphragm, emits acoustic vibration pulses caused by the powder contacting the surface
Implementation Method 2
using sensors like pressure transducers or piezoelectric sensors to convert these pulses into electrical signals
Data Source
AI summary
A powder feed rate sensor includes a surface or diaphragm configured to detect powder feed rate.