Grid Assembly for Ion Beam Steering

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Solution Overview

Problem

Ion beam sputtering operations result in non-uniform target material wear, leading to premature depletion and contamination of substrates due to uneven sputtering rates, necessitating early target replacement and recycling.

Innovation Solution

The use of a grid assembly with strategically positioned holes in the ion beam system to steer and distribute ion beamlets asymmetrically, ensuring more uniform material deposition and reducing the risk of target material wear through to the base plate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If ion beam sputtering is applied to target material, then material deposition on substrate is achieved, but non-uniform target wear occurs leading to premature depletion

Engineering Contradiction:
Improvedeposition rateVSAvoiduniformity of target wear
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The ion beam is divided into multiple beamlets that pass through individually addressable holes in the grid assembly, allowing independent control of sputtering in different target regions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts ion beam distribution by selectively activating or deactivating specific beamlets based on real-time monitoring of target wear, enabling non-uniform sputtering patterns that compensate for uneven target consumption

Inventive Principle:
Principle #15Dynamics

2Loss of substance

If sputtering continues until target depletion, then maximum material utilization is achieved, but substrate contamination occurs from base plate sputtering

Engineering Contradiction:
Improvetarget material utilizationVSAvoidsubstrate contamination
Core Design Contradiction:
Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary assessment of target wear using optical emission spectroscopy and adjusts ion beam distribution before base plate exposure occurs, extending target life by preventing the harmful condition of substrate contamination

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Real-time monitoring of plasma emission spectra provides feedback on target composition and wear state, enabling dynamic adjustment of sputtering parameters to maximize material utilization while preventing base plate sputtering

Inventive Principle:
Principle #23Feedback

3Productivity

If ion beam is concentrated on specific target areas, then localized sputtering efficiency is improved, but target wear becomes highly non-uniform

Engineering Contradiction:
Improvelocalized sputtering rateVSAvoidtarget material distribution uniformity
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

Different regions of the target receive customized ion beam treatment through selective activation of beamlets, with each region's sputtering parameters optimized for its specific requirements while maintaining overall target stability

Inventive Principle:
Principle #3Local quality

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 deposition uniformity across substrates, extends the useful lifecycle of target materials by preventing premature wear and contamination, and allows for more efficient multi-layer coating applications.

Implementation Method 1

A method for steering a beamlet of ions from an ion source includes positioning a screen grid downstream from or adjacent to a discharge chamber that provides the ions. The screen grid comprises a plurality of holes formed within the grid. Each hole in the screen grid has a center axis. A desired steering angle for each beamlet may be determined based on the orientation of the center axis of each hole in the screen grid.

Methodology Applied
Scientific EffectElectrostatic field: Electric Field

Data Source

PatentEP2625306B1Grid providing beamlet steering
Publication Date: 2020.09.30 VEECO INSTRUMENTS INC
  • EP2625306B1 patent drawingFigure 1
  • EP2625306B1 patent drawingFigure 2
  • EP2625306B1 patent drawingFigure 3

AI summary

A grid assembly (114, 300) coupled to a discharge chamber of an ion beam source (102) is configured for steering ion beamlets emitted from the discharge chamber at circularly asymmetrically determined steering angles. The grid assembly 114, 300) includes at least a first and a second grid (302, 304) with a substantially circular pattern of holes, wherein each grid (302, 304) comprises holes positioned adjacent to one another. A plurality of the holes of the second grid (304) is positioned with offsets relative to corresponding holes in the first grid (302). Due to the offsets in the holes in the second grid (304), ions passing through the offset holes are electrostatically attracted towards the closest circumferential portion of the downstream offset holes. Thus, the trajectories of ions passing through the offset holes are altered. The beamlet is steered by predetermined asymmetric angles. The predetermined steering angles are dependent upon the hole offsets, voltage applied to the grids 302, 304), and the distance between the grids (302, 304).