Sub-one Technology, Inc.

Duralar Technologies, LLC

Karthik Boinapally

William John Boardman

Deepak Upadhyaya

Thomas B Casserly

Duc Doan

Pankaj Jyoti Hazarika

Matthew MaMoody

Charles N Dornfest

Andrew William Tudhope

William J Boardman

A method and apparatus for plasma enhanced chemical vapor deposition to an interior region of a hollow, tubular, high aspect ratio workpiece are disclosed. A plurality of anodes are disposed in axially spaced apart arrangement, to the interior of the workpiece. A process gas is introduced into the region. A respective individualized DC or pulsed DC bias is applied to each of the anodes. The bias excites the process gas into a plasma. The workpiece is biased in a hollow cathode arrangement. Pressure is controlled in the interior region to maintain the plasma. An elongated support tube arranges the anodes, and receives a process gas tube. A current splitter provides a respective selected proportion of a total current to each anode. One or more notch diffusers or chamber diffusers may diffuse the process gas or a plasma moderating gas. Plasma impedance and distribution may be controlled using various means.

Multiple anode plasma for CVD in a hollow article

Chemical vapor deposition for an interior of a hollow article with high aspect ratio

Enhanced corrosion resistance is achieved in a coating by using a germanium-containing precursor and hollow cathode techniques to form a first layer directly on the surface of a workpiece, prior to forming an outer layer, such as a layer of diamond-like carbon (DLC). The use of a germanium or germanium-carbide precursor reduces film stress and enables an increase in the thickness of the subsequently formed DLC. Germanium incorporation also reduces the porosity of the layer. In one embodiment, a cap layer containing germanium is added after the DLC in order to further reduce the susceptibility of the coating to chemical penetration from the top.

Corrosion-resistant internal coating method using a germanium-containing precursor and hollow cathode techniques

Plasma Enhanced Bonding (PEB) during a coating process is used to improve both adhesion and corrosion resistance of the resulting coating. New interfacial compounds may be formed, offering the increased resistance to corrosion, as well as enhanced bonding to the workpiece being coated and any subsequently formed layer, such as diamond-like carbon. In one embodiment, the PEB processing is employed during coating of at least one interior surface of the workpiece, which may be a pipe. In a first step, a thin film is deposited. Then, the film is exposed to a high energy etch-back plasma. This two-step cycle of depositing a film and then providing bombardment of the film may be repeated a number of times. Typically, the deposition step of the cycle is much shorter than the bombardment step.

Plasma enhanced bonding for improving adhesion and corrosion resistance of deposited films

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Fremont, CA, United States of America

Karthik Boinapally