Substrate Gas Flow Modulation for Uniform Plasma Etching
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Solution Overview
Problem
Existing substrate processing technologies face limitations in achieving uniform plasma etching due to insufficient control over the gas supply, leading to variations in etching rates across different regions of the substrate.
Innovation Solution
A substrate processing device and method that control the gas supply profile by alternately adjusting the flow rate of process gas through flow control valves, ensuring a flow rate greater than or less than the average flow rate, to maintain a consistent etching rate across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a constant average flow rate of process gas is supplied to the chamber, then the gas supply is simple to control, but the plasma uniformity across the substrate is insufficient
Solution Approach 1:
The gas supply control unit alternates between supplying at a flow rate higher than the average flow rate and supplying at a flow rate lower than the average flow rate during the process time. This periodic variation in gas supply creates temporal fluctuations that compensate for spatial non-uniformities in plasma distribution, achieving uniform etching across the substrate without requiring complex spatial gas distribution systems
2Productivity
If the gas supply flow rate is increased to improve etching speed, then productivity increases, but the etching uniformity across different regions deteriorates
Solution Approach 1:
By periodically alternating between high and low flow rate supply phases, the system maintains the average flow rate necessary for high productivity while the temporal variations compensate for spatial non-uniformities, achieving both high etching speed and uniform etching distribution across the substrate
3Manufacturing precision
If the gas supply flow rate is decreased to improve etching uniformity, then plasma uniformity improves, but the overall etching rate and productivity decrease
Solution Approach 1:
The periodic alternation between high and low flow rates allows the system to maintain a higher average flow rate (preserving productivity) while the temporal fluctuations create conditions that promote uniform plasma distribution and uniform etching across the substrate
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
This approach achieves uniform etching rates across the substrate, particularly at the center and edge regions, enhancing processing efficiency and yield by adjusting the internal chamber state through controlled gas supply.
Implementation Method 1
the flow control valve controlling a flow rate of the process gas supplied through a gas supply line
Implementation Method 2
a plasma source generating plasma from the process gas supplied to the processing space
Implementation Method 3
an electromagnetic field is formed in an internal space of a chamber, and the electromagnetic field excites a process gas provided in the chamber into a plasma state
Implementation Method 4
The etching process is performed as ion particles contained in plasma collide with the substrate
Data Source
AI summary
The substrate processing device includes a chamber in which a processing space for processing a substrate is formed, a substrate support unit supporting the substrate in the processing space, a gas supply portion supplying process gas to the processing space, a gas supply unit supplying gas to the gas supply portion, and a controller connected to the gas supply unit, wherein the gas supply unit includes a flow control valve controlling a flow rate of the process gas supplied through a gas supply line, and the controller controls, during a first time, the flow control valve to alternately provide supply of a flow rate greater than an average flow rate for the first time and supply of a flow rate less than the average flow rate.