Cathode RF asymmetry detection probe for semiconductor RF plasma processing equipment
AssigneeLam Research Corporation
InventorsMaolin Long, Alex Paterson
Life of this patent
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Abstract
Apparatuses, systems, and techniques for characterizing asymmetry effects caused by cathode designs, ESC designs, cable routing, and process chamber geometries are provided. Such apparatuses, systems, and techniques may include, for example, a rotatable RF probe assembly in physical contact to a conductive plate disposed on a surface of a pedestal.
Claims24
An apparatus for evaluating radio-frequency (RF) electromagnetic field symmetry of an electrode of a pedestal of a semiconductor processing chamber, the apparatus comprising:
- a radio-frequency (RF) probe assembly configured to rotate about a first axis relative to a grounding plate, the grounding plate configured to interface with the semiconductor processing chamber and including an aperture, wherein the RF probe assembly includes:
- a radial member positioned on a first side of the grounding plate that faces the pedestal when the grounding plate is interfaced with the semiconductor processing chamber,
- a first conductive pin that is supported by the radial member and radially offset from the first axis along a second axis perpendicular to the first axis, and
- a first electrically conductive path leading from the first conductive pin, through the aperture, and to a location accessible from a second side of the grounding plate that is opposite the first side, wherein the first electrically conductive path is electrically isolated from the grounding plate.
A method for operating an apparatus for evaluating radio-frequency (RF) electromagnetic field symmetry of an electrode of a pedestal of a semiconductor processing chamber, apparatus including an FR probe assembly and the method comprising:
- measuring a first radio-frequency (RF) signal at a first position using the RF probe assembly, the RF probe assembly configured to rotate about a first axis relative to a grounding plate, the grounding plate configured to interface with the semiconductor processing chamber, the grounding plate including an aperture, wherein the RF probe assembly includes:
- a radial member positioned on a first side of the grounding plate that faces the pedestal when the grounding plate is interfaced with the semiconductor processing chamber,
- a first conductive pin that is supported by the radial member and radially offset from the first axis along a second axis perpendicular to the first axis, and
- a first electrically conductive path leading from the first conductive pin, through the aperture, and to a location accessible from a second side of the grounding plate that is opposite the first side, wherein the first electrically conductive path is electrically isolated from the grounding plate;
- and
- measuring a second radio-frequency (RF) signal at a second position using the RF probe assembly, wherein the first position and the second position are symmetric in a plane parallel to the second axis.
Dependencies are inferred from the claim text.