Coaxial Hollow Cathode Plasma Assisted Directed Vapor Deposition and Related Method Thereof

Abstract

A plasma generation process that is more optimized for vapor deposition processes in general, and particularly for directed vapor deposition processing. The features of such an approach enables a robust and reliable coaxial plasma capability in which the plasma jet is coaxial with the vapor plume, rather than the orthogonal configuration creating the previous disadvantages. In this way, the previous deformation of the vapor gas jet by the work gas stream of the hollow cathode pipe can be avoided and the carrier gas consumption needed for shaping the vapor plume can be significantly decreased.

Description

RELATED APPLICATIONS[0001]The present application claims priority from U.S. Provisional Application Ser. No. 61 / 154,890, filed Feb. 24, 2009, entitled “Coaxial Hollow Cathode Plasma Assisted Directed Vapor Deposition and Related Method Thereof and U.S. Provisional Application Ser. No. 61 / 248,082, filed Oct. 2, 2009, entitled “Coaxial Hollow Cathode Plasma Assisted Directed Vapor Deposition and Related Method Thereof;” the disclosures of which are hereby incorporated by reference herein in their entirety.BACKGROUND OF THE INVENTION[0002]Coatings applied by physical vapor deposition (PVD) processes—typically performed in a vacuum—are widely used in various applications such as in creating barrier layers for packaging films, metalizing plastics for flexible electronics and EMI shielding purposes, depositing scratch-proof, corrosion protection or decorative layers on various raw materials, or for controlling the electrical, optical and tribological properties of components, tools and ma...

AI Technical Summary

Benefits of technology

The present invention provides a new plasma system that can generate a robust and reliable plasma capability. This is achieved by coaxially aligning the plasma generating discharge with the vapor plume, which avoids deformation of the vapor gas jet and reduces the carrier gas consumption required for shaping the vapor plume. The use of multiple small pipes allows for individual control of working gas flow and current for each pipe, enabling synchronized sweeping of the plasma plume with the vapor jet. Additionally, magnetic tuning of the discharge can further increase particle energy and optimize spatial density distribution. The new plasma system also has enhanced electric insulating capability up to the kV range, allowing for convenient biasing of the plasma source with respect to the chamber and substrate for heating or etching steps.

Problems solved by technology

Without applying additional aids, however, the layers grown at high rates are usually of poor quality.

Another drawback of conventional thermal evaporators—the fairly low utilization of the evaporant material when coating smaller substrates such as tools, engine parts or fibers—stems from the inherently divergent propagation characteristic of the vapor particles.

However, it was also found in the course of investigations that DVD at this stage was restricted to deposition of porous or columnar microstructures.

As in conventional EB-PVD, this is caused by the limited kinetic energy of the thermally generated vapor atoms.

For other applications or also for certain layers in the multilayer systems required in turbine blade coating, however, dense structures are demanded.

The conventional plasma assisted deposition process has several drawbacks, however.

Second, the conventional approach requires the use of high argon working gas flow rates which has adverse economic consequences.

Third, there is no means for sweeping the vapor plume from side to side (i.e. paint spraying a large area surface) in the conventional arrangement without significantly effecting the plasma properties.

Fourth, the conventional plasma generation approach provides inadequate cleaning, etching, and heating properties for some applications (i.e. the deposition of high temperature materials onto large area substrates).

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