PEALD Film Formation Control With Dual Controllers and Pulsed RF
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Solution Overview
Problem
Conventional plasma atomic layer deposition (PEALD) methods experience inaccurate control times and low process stability due to communication delays and fluctuations in valve and power source operations, leading to inconsistent film formation on substrates.
Innovation Solution
A method involving direct control of power sources and valve units by a second controller, utilizing pulsed power modes and impedance matching with electronically variable capacitors, to achieve precise signal transmission and stable film formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fast ON/OFF operations of valves and power source are performed to achieve high throughput, then productivity is improved, but communication delay and inaccurate operations occur resulting in worsened reliability
Solution Approach 1:
The control system is segmented into two distinct controllers: a first controller for high-level process control and recipe management, and a second controller for real-time precise control of valves and power sources. This segmentation allows the second controller to handle fast ON/OFF operations with millisecond-level accuracy without being constrained by communication delays to the first controller, thus resolving the contradiction between high throughput and control accuracy.
Solution Approach 2:
The second controller acts as an intermediary between the first controller and the actual process equipment (valves and power sources). It receives control signals from the first controller and translates them into precise, real-time control actions, eliminating direct communication delays between the first controller and the fast-responding equipment, thereby enabling both high throughput and accurate control.
2Device complexity
If conventional EtherNet communication is used for controller communication, then device complexity is reduced, but control accuracy time deteriorates with fluctuations up to 50 milliseconds
Solution Approach 1:
The control architecture is divided into two levels: the first controller handles high-level process management through standard EtherNet communication, while the second controller handles real-time control with direct, low-latency connections to valves and power sources. This segmentation isolates the communication delay issue to the first controller level, allowing the second controller to maintain millisecond-level accuracy without being affected by EtherNet communication fluctuations.
3Productivity
If RF power is applied for plasma generation, then film formation efficiency is improved, but thermal budget to underlayers increases
Solution Approach 1:
The plasma generation uses periodic RF power application with controlled duty cycles, where power is applied in pulses rather than continuously. This periodic action allows plasma formation for efficient film deposition while providing cooling intervals that prevent excessive heat accumulation in the substrate and underlying layers, thus resolving the contradiction between film formation efficiency and thermal budget management.
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 method ensures control accuracy within 1 millisecond and enhances process stability, resulting in uniform film formation and reduced communication delays, thereby improving throughput and reliability.
Implementation Method 1
at least one of source gas and a reactant may be activated by a power applied to a reactor in-situ or remotely to form a film on the substrate
Implementation Method 2
A plasma atomic layer deposition (PEALD hereinafter) is a method of forming a film on a substrate at low temperature
Implementation Method 3
impedance matching with electronically variable capacitors
Data Source
AI summary
Provided is a method of improving a control time accuracy while a command signal is transmitted to a substrate processing apparatus from a controller, and a process stability while processing a substrate. A method of forming the film using it comprises inputting process control parameters into a first controller, downloading the process control parameters to a second controller from the first controller, and forming the film on the substrate.