Spatial optical emission spectroscopy for etch uniformity
Inventors
Erickson, Blake • Berding, Keith • Kutney, Michael • Zhu, Zhaozhao • Wu, Tsung Feng • Willwerth, Michael D. • Ludwig, Jeffrey
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-12405164-B2
Publication Date
2025-09-02
Expiration Date
Abstract
An apparatus includes a base component and a plurality of collimators housed within the base component. Each collimator of the plurality of collimators corresponds to a respective location of a plurality of locations of a wafer in an etch chamber. The plurality of locations includes a center location of the wafer, a plurality of inner ring locations along an inner ring of the wafer associated with a first set of radially symmetric optical emission spectroscopy (OES) signal sampling paths, and a plurality of outer ring locations along an outer ring of the wafer associated with a second set of radially symmetric OES signal sampling paths.
Core Innovation
The invention provides spatial optical emission spectroscopy (OES) for analyzing plasma etch uniformity by sampling OES signals along radially symmetric OES signal sampling paths associated with wafer locations in an etch chamber. A set of locations comprises a center location, a plurality of inner ring locations along an inner ring of the wafer, and a plurality of outer ring locations along an outer ring of the wafer. Each location corresponds to a respective OES signal captured for spatial OES analysis.
An apparatus includes a base component and a plurality of collimators housed within the base component, where each collimator corresponds to a respective location of the wafer. The inner ring locations are associated with a first set of radially symmetric optical emission spectroscopy (OES) signal sampling paths, and the outer ring locations are associated with a second set of radially symmetric OES signal sampling paths. The collected OES signals are routed to an optical detector and used for spatial OES analysis.
A processing device initiates an iteration of an etch process to etch a wafer using an etch recipe, receives the spatial OES analysis of a plurality of OES signals from an optical detector, and performs one or more actions related to etch uniformity based on the spatial OES analysis. The actions relate to etch uniformity and can include optimizing, monitoring, and/or controlling etch uniformity. The spatial OES analysis can also determine etch rates for respective locations.
Claims Coverage
Independent claims cover an apparatus, a system, and a method that perform spatial OES-based assessment and actions for etch uniformity using radially symmetric sampling paths for center, inner ring, and outer ring wafer locations. Across the independent claims, at least three main inventive features are repeatedly emphasized: a spatial OES sampling layout, receiving spatial OES analysis mapped to wafer locations, and performing actions related to etch uniformity based on that spatial analysis.
Base component with multiple collimators for center, inner ring, and outer ring radially symmetric sampling paths
A base component and a plurality of collimators housed within the base component, where each collimator corresponds to a respective location of a plurality of locations of a wafer in an etch chamber, the plurality of locations comprising a center location, inner ring locations along an inner ring associated with a first set of radially symmetric OES signal sampling paths, and outer ring locations along an outer ring associated with a second set of radially symmetric OES signal sampling paths.
Iterative etch process using spatial OES analysis mapped to wafer locations
Initiating an iteration of an etch process to etch a wafer using an etch recipe; receiving, from an optical detector, a spatial optical emission spectroscopy (OES) analysis of a plurality of OES signals, where each OES signal corresponds to a respective location of a plurality of locations including a center location, inner ring locations associated with a first set of radially symmetric OES signal sampling paths, and outer ring locations associated with a second set of radially symmetric OES signal sampling paths.
Actions related to etch uniformity based on spatial OES analysis
Performing one or more actions related to etch uniformity based on the spatial OES analysis, where the spatial OES analysis is received from an optical detector and is used by a processing device as part of the iteration of the etch process.
The independent claims collectively define spatial OES sampling using multiple collimators for center/inner ring/outer ring wafer locations with radially symmetric sampling paths, then receiving spatial OES analysis mapped to those locations. Based on the spatial OES analysis, the processing device performs one or more actions related to etch uniformity during an iteration of an etch process.
Stated Advantages
Not explicitly described in patent.
Documented Applications
Not explicitly described in patent.
Interested in licensing this patent?