Separated Gas Inlet Structure Blocks Plasma Backflow
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Solution Overview
Problem
In semiconductor integrated circuit manufacturing, plasma backflow into the gas inlet channel during cleaning processes damages the gas inlet guide body due to high charges and plasma ignition, leading to erosion and pollution issues.
Innovation Solution
A separated gas inlet structure comprising two ceramic gas inlet nozzles, with a broken line type gas inlet channel design that prevents plasma backflow by physically blocking the electron path and reducing thermal expansion risks, facilitating easier installation and maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RF power is loaded on the top coupling window to clean the reaction chamber, then the cleaning effect on the cavity is improved, but plasma backflows into the gas inlet channel causing ignition and damage
Solution Approach 1:
The gas inlet guide body is divided into an upper gas inlet guide body and a lower gas inlet guide body, separated by a partition plate. This segmentation creates a physical barrier that blocks plasma backflow into the gas inlet channel while maintaining the cleaning function on the coupling window.
Solution Approach 2:
A partition plate is introduced as an intermediary component between the upper and lower gas inlet guide bodies. The partition plate acts as a physical barrier that prevents plasma from traveling up the gas inlet channel while allowing the gas flow to function normally.
2Productivity
If the gas inlet channel is positioned close to the RF power point for efficient gas delivery, then the gas delivery efficiency is improved, but the risk of plasma ignition in the channel increases
Solution Approach 1:
Dividing the gas inlet guide body into upper and lower sections with a partition plate creates a physical discontinuity that interrupts the plasma path while maintaining gas flow efficiency through the separated channels.
Solution Approach 2:
The partition plate extracts the harmful plasma from the gas inlet channel by creating a physical barrier, separating the plasma-containing region from the gas delivery path while maintaining close proximity for efficient gas delivery.
3Device complexity
If a single integrated gas inlet guide body is used, then the structure is simple, but plasma backflow causes erosion and pollution of the entire guide body
Solution Approach 1:
The gas inlet guide body is segmented into upper and lower parts that can be separately replaced. The lower part that is exposed to plasma can be replaced without replacing the entire guide body, reducing waste and cost while maintaining structural simplicity.
Solution Approach 2:
The upper gas inlet guide body can be recovered and reused after the lower part is replaced, as it is not damaged by plasma. This reduces material waste and lowers operational costs.
4Ease of manufacture
If the ceramic gas inlet nozzle is made as a single piece, then manufacturing is simpler, but thermal expansion during plasma cleaning can cause cracking
Solution Approach 1:
The ceramic gas inlet nozzle is divided into upper and lower nozzles that can expand independently. This segmentation reduces thermal stress concentration and prevents cracking while maintaining manufacturing simplicity for each individual nozzle component.
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
Effectively blocks plasma backflow, prevents damage from high charges and plasma ignition, and avoids material erosion, ensuring the gas inlet structure remains intact and functional, while simplifying processing and maintenance.
Implementation Method 1
A separated gas inlet structure for blocking plasma backflow... the broken line type gas inlet channel design prevents plasma backflow by physically blocking the electron path
Implementation Method 2
load RF power on the top to ionize the cleaning gas for taking away these pollution particles
Implementation Method 3
the plasma accelerates to reach the surface of the metal material under the action of bias voltage
Data Source
AI summary
A separated gas inlet structure for blocking plasma backflow includes a gas inlet flange and an upper gas inlet nozzle and a lower gas inlet nozzle made of ceramic materials. The upper gas inlet nozzle is coaxially nested or stacked at the top of the lower gas inlet nozzle; a broken line type gas inlet channel is in the upper gas inlet nozzle and the lower gas inlet nozzle and the gas inlet channel includes an upper axial channel, a radial channel, a lower axial channel and a gas outlet; the radial channel or the lower axial channel is at a mounting matching part of the upper gas inlet nozzle and the lower gas inlet nozzle; and the top of the lower axial channel points to a bottom wall surface of the upper gas inlet nozzle.