Wide range electron impact ion source for a mass spectrometer
Inventors
Mueller, Norbert • Vanoni, Daniel • Wagner, Jochen
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-12106953-B2
Publication Date
2024-10-01
Expiration Date
Abstract
A wide-range ion source for a mass spectrometer comprises a first portion and a second portion that is positioned downstream of the first portion. The first portion includes an anode and a first filament that is positioned proximate the anode and secured in place relative to the anode. The first filament is exposed to a pressure of a process chamber. A first electron repeller has at least a partially circular shape. The second portion includes a tubular anode, a second filament surrounding the tubular anode, an extraction lens defining an opening and a focus lens to conduct ions into a volume.
Core Innovation
The invention provides a wide-range electron impact ion source for a mass spectrometer system that operates for measuring residual gas at low pressure levels and for measuring process gas composition at high pressure levels. The problem addressed is measuring process gas composition at high pressure levels and residual gas at low pressure levels using a wide-range ion source in a mass spectrometer system.
The wide-range ion source is structured with a first portion and a second portion positioned downstream of the first portion. The first portion includes an anode with a first filament positioned proximate the anode and secured in place relative to the anode, where the first filament is exposed to a pressure of a process chamber, and the first portion further includes a first electron repeller comprising at least a partially circular shape.
The second portion is positioned downstream and includes a tubular anode, a second filament surrounding the tubular anode, an extraction lens defining an opening, and a focus lens configured to conduct ions into a volume. The invention includes measuring under low pressure conditions using the first filament and measuring under high pressure conditions using the second filament, and further includes monitoring existence of products created by the process.
The method and source include checking cleanliness of the vacuum system and the mass spectrometer system for low-pressure operation, and checking cleanliness of the process gas for high-pressure operation. The source structure is further described with optional features including multiple electron entrance openings of the tubular anode, filaments implemented as coils, and a ceramic insulator configured to form a seal between the tubular anode and the extraction lens.
Claims Coverage
The document includes three independent claims across two distinct claim sets: a low-/high-pressure measurement method using a wide-range ion source, a structural definition of the wide-range ion source, and another method for measuring process gas composition and residual gas with the same wide-range ion source. The inventive features in these independent claims mainly relate to switching between low-pressure and high-pressure operation using first and second filaments, and a two-portion ion source architecture with specific ion optics elements to conduct ions into a volume.
Low-/high-pressure measurement using two filaments with cleanliness checks and product monitoring
A method for measuring process gas composition at high pressure levels and a residual gas at low pressure levels using a wide-range ion source in a mass spectrometer system, comprising setting the mass spectrometer to a mode of operation under low pressure, heating a first filament to a predetermined emission current using a first filament current, measuring residual gas composition, checking cleanliness of a vacuum system and the mass spectrometer system, turning off the first filament current, setting the mass spectrometer to a mode under high pressure conditions, heating a second filament to a predetermined emission current using a second filament current, measuring process gas composition, checking cleanliness of the process gas, and monitoring existence of products created by the process.
Two-portion wide-range ion source architecture with extraction and focus lenses
A wide-range ion source for a mass spectrometer comprising a first portion including an anode, a first filament positioned proximate the anode and secured in place relative to the anode, wherein the first filament is exposed to a pressure of a process chamber, a first electron repeller comprising at least a partially circular shape, and a second portion positioned downstream of the first portion and including a tubular anode, the second portion comprising a second filament surrounding the tubular anode, an extraction lens defining an opening, and a focus lens configured to conduct ions into a volume.
Residual gas and process gas measuring using first and second portions of the wide-range ion source
A method for measuring process gas composition and a residual gas using a wide-range ion source in a mass spectrometer system, comprising structuring a first portion to include an anode, a first filament positioned proximate the anode and secured in place relative to the anode and an electron repeller, wherein the first filament is exposed to a pressure of a process chamber; heating the first filament to a first predetermined emission current to measure a residual gas composition under low pressure conditions; structuring a second portion positioned downstream to include a tubular anode, a second filament surrounding the tubular anode, an extraction lens defining an opening, and a focus lens configured to conduct ions into a volume; heating the second filament to a second predetermined emission current to measure a composition of a process gas under high pressure conditions; and monitoring existence of products created by a process.
Across the independent claims, the core coverage combines low-pressure residual gas measurement and high-pressure process gas composition measurement using first and second filaments operated in respective pressure modes, and a two-portion wide-range ion source architecture in which the first portion includes a first electron repeller and a first filament exposed to process-chamber pressure, while the second portion downstream includes a tubular anode, a surrounding second filament, an extraction lens defining an opening, and a focus lens configured to conduct ions into a volume.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
Interested in licensing this patent?