Accumulator Valve Pulsing for High-Temperature Precursor Pressure Control
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Solution Overview
Problem
Current reactor systems face challenges in accurately controlling precursor pressure in high-temperature applications, as existing pressure controllers and valving are not suited for such conditions, leading to inconsistencies in wafer processing and reduced throughput.
Innovation Solution
Implementing a reactor system that uses valve pulsing to control precursor pressure by running a pressure control module to process signals from a pressure sensor, generating control signals for high-speed valves to adjust accumulator pressure, and employing a PID control loop with pulse-density modulation to manage valve operation between fully open and closed positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If existing pressure controllers and valving are used in high-temperature applications, then pressure control is attempted, but the controllers are not suited for high-temperature conditions leading to inconsistencies in wafer processing
Solution Approach 1:
The patent extracts the pressure control function from the high-temperature environment by placing the pressure controller in a temperature-controlled zone separate from the reaction chamber, while still enabling control of the accumulator that feeds the reaction chamber. This allows the controller to operate at lower temperatures while maintaining influence over the high-temperature processing environment.
Solution Approach 2:
The patent introduces an intermediary accumulator as a buffer between the pressure controller and the reaction chamber. The accumulator can be filled at controlled temperatures and then delivers precursor to the high-temperature reaction chamber, mediating between the temperature zones and enabling consistent pressure control without exposing the controller to extreme temperatures.
2Manufacturing precision
If pressure control is improved to enhance pulse-to-pulse consistency, then wafer processing consistency improves, but existing controllers cannot operate in high-temperature environments
Solution Approach 1:
The system segments the pressure control function from the high-temperature reaction environment. The pressure controller operates independently in a controlled temperature zone, while the accumulator and delivery system handle the high-temperature interface with the reaction chamber. This segmentation allows precise pressure control without exposing the controller to thermal damage.
Solution Approach 2:
The patent replaces traditional mechanical pressure control mechanisms that cannot withstand high temperatures with an electronically controlled system. The pressure controller uses electronic sensing and control circuitry to regulate pressure through controlled filling of the accumulator, enabling precise control in environments where mechanical components would fail.
3Measurement precision
If valve pulsing is implemented to control accumulator pressure, then precise pressure control is achieved, but rapid valve operation is required
Solution Approach 1:
The patent implements periodic valve pulsing to control accumulator pressure. Instead of requiring continuously modulated valve positions, the system uses periodic opening and closing of the fill valve in synchronization with the dosing cycle. This periodic action simplifies valve requirements while achieving precise pressure control through timing and duration of each pulse.
Solution Approach 2:
The system dynamically adjusts the pulsing frequency and duration of the fill valve based on real-time pressure feedback from the accumulator. The controller modifies the timing and length of valve pulses to maintain optimal pressure, enabling adaptive control that responds to changing conditions without requiring complex valve mechanisms.
Data Source
AI summary
A reactor system configured to use valve pulsing to control precursor pressure as part of substrate or other processing. A controller in the reactor system runs a pressure control module to process pressure signals from a pressure sensor sensing pressure within an accumulator disposed between a reaction chamber and a precursor source vessel. Based on a pressure set point for the accumulator and the sensed pressure feedback, the controller generates valve control or valve pulsing signals to operate one or more fill valves used to control fill of the accumulator with gas (e.g., precursor) from the precursor source vessel. The fill valves may be high-speed diaphragm valves configured for operation in high temperature applications to be fully opened or fully closed, and the control signals cause the valves to rapidly pulse open and closed to adjust the pressure within the accumulator.