Ion Source In-Situ Cleaning via Heating Units
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Solution Overview
Problem
Conventional ion source cleaning methods are inefficient and costly, leading to contamination and ion source failure in semiconductor processing due to residual coatings from feed gases like carborane or diborane, which alter electrical characteristics and cause contamination in subsequent implantations.
Innovation Solution
Incorporating heating units near the ion source to elevate temperatures, allowing cleaning gases to ionize and react effectively, removing residues from the ion source walls, with the heating units being strategically placed within the ion source or as part of its structure to maintain uniform high temperatures during cleaning processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional cleaning methods are used to remove coating from ion source walls, then the ion source can be cleaned, but the cleaning process is inefficient, costly, and requires disassembly of the ion source
Solution Approach 1:
The ion source is equipped with heating units and cleaning gas injection capabilities that enable it to clean itself in-situ without disassembly. The heating units raise the temperature of the ion source walls to facilitate the removal of coatings by cleaning gases, allowing the system to perform maintenance autonomously during operation.
Solution Approach 2:
The heating units are activated before the cleaning process to pre-heat the ion source walls to optimal temperatures for coating removal. This preliminary heating action prepares the surface for effective cleaning by cleaning gases, ensuring that the cleaning process proceeds efficiently without requiring mechanical disassembly.
2Reliability
If the ion source is cleaned by removal and disassembly, then cleaning can be performed, but the process is time-consuming and does not adequately clean all surfaces
Solution Approach 1:
The ion source performs self-cleaning through integrated heating units and cleaning gas injection systems that access all internal surfaces including the extraction aperture and chamber walls. This self-service capability ensures complete cleaning of all surfaces without the time loss associated with disassembly and reassembly procedures.
Solution Approach 2:
The cleaning process can be performed continuously or periodically during ion source operation without interrupting the overall system functionality. The heating and cleaning gas injection proceed continuously to ensure all surfaces are thoroughly cleaned while maintaining operational readiness.
3Temperature
If heating units are placed in close proximity to the ion source inner volume, then uniform high temperature can be achieved for effective cleaning, but the device structure becomes more complex
Solution Approach 1:
The heating units serve multiple functions: they heat the ion source walls for cleaning, maintain operational temperature during ion generation, and facilitate coating removal. This multi-functionality reduces the need for separate heating systems for different operations, thereby limiting the increase in device complexity.
Solution Approach 2:
The heating units act as intermediaries between the power supply system and the ion source walls, transferring thermal energy efficiently to achieve uniform temperature distribution. This intermediary role allows for controlled and uniform heating without requiring complex direct heating mechanisms integrated into the wall structure itself.
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 solution enables more efficient and effective cleaning of the ion source, preventing coating formation and contamination, thereby extending the ion source's lifespan and reducing maintenance costs by ensuring consistent and uniform temperature control during both normal operation and cleaning processes.
Implementation Method 1
one or more heating units are placed in close proximity to the inner volume of the ion source, so as to affect the temperature within the ion source
Implementation Method 2
Cleaning gas is flowed into the ion source, where it is ionized and/or become reactive species, either by the cathode, as in normal operating mode, or by the heat generated by the heating units
Data Source
AI summary
An ion source and method of cleaning are disclosed. One or more heating units are placed in close proximity to the inner volume of the ion source, so as to affect the temperature within the ion source. In one embodiment, one or more walls of the ion source have recesses into which heating units are inserted. In another embodiment, one or more walls of the ion source are constructed of a conducting circuit and an insulating layer. By utilizing heating units near the ion source, it is possible to develop new methods of cleaning the ion source. Cleaning gas is flowed into the ion source, where it is ionized, either by the cathode, as in normal operating mode, or by the heat generated by the heating units. The cleaning gas is able to remove residue from the walls of the ion source more effectively due to the elevated temperature.