Segmented Plasma Etching with Intermediate Chamber Cleaning
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Solution Overview
Problem
Existing etching processes for semiconductor devices face challenges in maintaining etching uniformity, particularly for high aspect ratio contact holes, due to polymer deposition and arcing issues, leading to degraded performance and reduced productivity.
Innovation Solution
A segmented etching process with intermediate cleaning steps is employed, where the etching process is divided into multiple stages with intermediate cleaning phases to maintain a consistent internal environment in the process chamber, using optical emission spectroscopy to monitor and adjust the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a continuous etching process is used to maintain productivity, then manufacturing efficiency is improved, but etching uniformity deteriorates due to polymer deposition and arcing issues
Solution Approach 1:
The etching process is divided into multiple segments with intermediate cleaning steps. The controller pauses the etching process at predetermined intervals, transfers the substrate to a storage location, performs cleaning of the process chamber, and then resumes etching. This segmentation prevents polymer deposition accumulation and arcing issues while maintaining overall productivity.
Solution Approach 2:
The etching process implements periodic cleaning actions at predetermined time intervals or after etching for a predetermined depth. The controller periodically pauses etching to perform chamber cleaning, which removes deposited polymers and prevents arcing. This periodic intervention maintains etching uniformity without completely stopping the manufacturing process.
2Manufacturing precision
If intermediate cleaning steps are added to maintain etching uniformity, then manufacturing precision is improved, but process complexity increases
Solution Approach 1:
The system performs automatic self-service through the controller that monitors etching progress and automatically initiates cleaning operations at predetermined intervals or depth thresholds. The controller manages the pausing, substrate transfer, cleaning execution, and resumption without requiring manual intervention, thereby reducing operational complexity despite adding cleaning steps.
Solution Approach 2:
The controller uses feedback from etching monitoring to determine when to pause and initiate cleaning. By monitoring etching depth or process time and comparing against predetermined thresholds, the system automatically triggers cleaning operations only when necessary, optimizing the balance between uniformity and process simplicity.
3Reliability
If the etching process is paused for cleaning, then contaminant accumulation is reduced, but processing time increases
Solution Approach 1:
The cleaning operation is performed partially or excessively relative to the actual contamination level by using fixed predetermined intervals or depth thresholds. This approach ensures consistent process stability without requiring complex real-time contamination measurement, and the cleaning duration is optimized to be sufficient but not excessive to minimize time loss.
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 enhances etching uniformity and reduces contaminant accumulation, improving the quality and productivity of semiconductor devices by preventing rapid changes in the process chamber environment.
Implementation Method 1
The plasma etching process may be used to manufacture a semiconductor device in an etching apparatus. The etching apparatus may perform a plasma etching process on a semiconductor substrate by using plasma in a process chamber.
Implementation Method 2
using optical emission spectroscopy to monitor and adjust the etching process
Data Source
AI summary
An operation method of an etching apparatus includes transferring, from a load lock chamber to a process chamber, a substrate on which an etching target layer is formed, first etching the etching target layer on the substrate in a first etching time, transferring the substrate to a storage location in a state in a vacuum state, intermediate cleaning the process chamber in a first cleaning time, transferring the substrate from the storage location to the process chamber, second etching the etching target layer on the substrate in a second etching time, and returning the substrate to the load lock chamber. The etching target layer is formed in a predetermined etching pattern by the first etching and the second etching.