Plasma Chamber Cleaning Cycles for Mixed Metal-Nonmetal Deposits
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Solution Overview
Problem
Existing plasma cleaning methods are inadequate for effectively removing mixed depositions of metal and non-metal residues in semiconductor processing chambers, leading to particle generation and process inefficiencies.
Innovation Solution
A plasma processing method involving alternating cycles of metal and non-metal removal steps using specific gas mixtures to efficiently remove complex depositions, including a step for removing metal elements followed by non-metal elements, repeated multiple times to ensure complete removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional plasma cleaning methods are used, then the processing chamber can be cleaned, but mixed depositions of metal and non-metal cannot be sufficiently removed
Solution Approach 1:
The cleaning process is divided into multiple sequential steps, each targeting specific deposition types. The method segments the complex mixed deposition removal into: (1) fluorocarbon deposition removal step, (2) metal deposition removal step, and (3) silicon oxide deposition removal step. This segmentation allows each step to optimize for removing specific material types without interference from others, effectively addressing the inability of conventional single-step methods to remove mixed depositions.
Solution Approach 2:
The invention changes multiple parameters throughout the cleaning process including gas composition (switching between CF4, Cl2/BCl3, and O2/NF3), power levels (adjusting between 100-500W for different steps), and pressure conditions. These parameter changes enable the system to optimize cleaning effectiveness for different deposition types at different stages, transforming the cleaning capability from insufficient to highly effective for mixed depositions.
2Productivity
If plasma processing is performed frequently, then production efficiency increases, but deposition accumulation in the chamber worsens
Solution Approach 1:
The cleaning method implements continuous effective action by establishing a systematic multi-step process that completely removes all types of depositions (fluorocarbon, metal, and silicon oxide) without leaving residues. This continuous thorough cleaning capability allows plasma processing to be performed frequently without deposition accumulation, maintaining productivity while preventing substance buildup in the chamber.
Solution Approach 2:
The invention converts the harmful effect of deposition accumulation into a beneficial situation by using controlled plasma processing with specific gas compositions to transform and remove depositions systematically. The depositions that would normally accumulate and harm production are instead converted into removable compounds through the multi-step plasma cleaning process, enabling continuous high-productivity operation.
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 significantly reduces particle generation and enhances the stability of semiconductor processing by effectively removing mixed depositions, allowing for prolonged and stable mass production.
Implementation Method 1
a microwave ECR (Electron Cyclotron Resonance (ECR) plasma etching apparatus
Implementation Method 2
By the interaction between the microwave electric field generated from the radio frequency power supply 107 and the magnetic field generated by the electromagnet 108, the processing gas supplied into the processing chamber 100 is turned into plasma
Implementation Method 3
a non-metal removing step of removing the deposited film containing the non-metal element by using plasma different from the plasma in the metal removing step
Data Source
AI summary
An object of the present invention is to provide a plasma a processing method capable of removing complex depositions of metal and non-metal deposited in a processing chamber by etching processing of a wafer to reduce generation of particle due to the depositions, in a plasma processing method for plasma-etching the wafer such as a semiconductor substrate.According to the present invention, there is provided a plasma processing method for plasma-etching a sample in a processing chamber and plasma-cleaning the inside of the processing chamber, the method comprising: an etching step for plasma-etching a predetermined number of the samples; a metal removing step of removing a deposited film containing a metal element by using a plasma after the etching step; and a non-metal removing step of removing the deposited film containing the non-metal element by using a plasma different from the plasma in the metal removing step, in which the metal removing step and the non-metal removing step are repeated twice or more.