Concentration Sensor Calibration for Precursor Delivery
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Solution Overview
Problem
In semiconductor deposition processes, concentration sensors for precursor delivery become inaccurate over time due to precursor deposition, leading to variability in precursor delivery and non-uniformity of deposited films across substrates, necessitating consistent calibration across multiple systems.
Innovation Solution
A method and apparatus for calibrating concentration sensors using a precursor or chemical standard flow through a sensor assembly and gas delivery system, with a control system to monitor and compensate for sensor drift, ensuring accurate precursor delivery and extending sensor lifetime between maintenance cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If concentration sensors are used for precursor delivery over extended periods, then continuous monitoring capability is maintained, but sensor accuracy deteriorates due to precursor deposition and drift
Solution Approach 1:
The patent implements periodic recalibration of concentration sensors using chemical standards at defined intervals or trigger conditions. The system automatically introduces a chemical standard through the gas delivery system, measures the sensor response, and updates calibration parameters. This periodic intervention restores measurement accuracy without requiring continuous operation, resolving the contradiction between extended sensor use and maintained precision.
Solution Approach 2:
The system performs preliminary calibration actions by introducing chemical standards before actual precursor delivery measurements are critically affected by drift. The calibration sequence is triggered proactively based on usage counters, time intervals, or detected performance degradation thresholds, preventing accuracy deterioration before it impacts deposition uniformity.
2Productivity
If multiple deposition systems operate independently without standardized calibration, then system autonomy is maintained, but deposition uniformity deteriorates across substrates
Solution Approach 1:
The patent establishes a universal calibration framework where chemical standards serve as a common reference across multiple deposition systems. The same chemical standard can be used to calibrate sensors in different apparatuses, creating a standardized measurement baseline. This universality enables consistent precursor concentration measurements across systems while maintaining their operational independence, resolving the contradiction between autonomy and uniformity.
Solution Approach 2:
The system implements feedback mechanisms where sensor measurements are continuously compared against calibration data from chemical standards. This feedback loop allows each system to self-correct its measurements based on known reference values, ensuring that deposition parameters remain consistent across multiple apparatuses without requiring centralized control.
3Measurement precision
If sensor recalibration is performed frequently to maintain accuracy, then measurement precision is improved, but system downtime and complexity increase
Solution Approach 1:
The calibration system is designed to be self-service, where the deposition system automatically performs its own calibration using integrated chemical standards and control logic. The system autonomously triggers calibration sequences, introduces standards through existing gas delivery infrastructure, and updates calibration parameters without external intervention. This self-service capability maintains high measurement precision while avoiding the operational overhead and complexity of external calibration procedures.
Data Source
AI summary
Methods and apparatus for controlling precursor flow are provided. In embodiments, the methods and apparatus apparatus for controlling precursor flow to a deposition chamber, includes: an ampoule to output a precursor; a sensor assembly communicatively coupled to the ampoule; and a control system, wherein the control system is configured to calibrate the sensor assembly during flow of a precursor or a chemical standard through the sensor assembly.