Barrier layer process and arrangement

Abstract

A method an apparatus is described using atomic layer deposition to form a barrier layer onto a substrate. The coated substrate exhibits reduced permeation to oxygen and water vapor.

Description

Background of the invention [0001] The present invention relates to arrangements and methods for forming barrier layers on substrates to form diffusion barriers for oxygen and water vapor. More specifically, the present invention provides an apparatus and method in which a barrier layer is formed on a plastic substrate using atomic layer deposition. The resulting barrier will more closely conform to the substrate surface and reduce pinhole leakage and cracking. [0002] Food and pharmaceutical packaging often require low diffusion rates, especially for oxygen and water vapor. Glass packaging such as glass jars, airtight glass bottles have sufficiently low oxygen and water vapor transmission rates. Unfortunately, glass-based packaging is expensive. Despite the lower cost of polymer-based packaging, most polymer films of a thickness effective for packaging applications have undesirably high oxygen and water vapor permeability. Lower gas permeation rates can be achieved by la...

AI Technical Summary

Problems solved by technology

The most notable problem is that the polymer has a rough surface, and the film deposited by PECVD by thermal evaporation has poor compliance to the surface undulations of the plastic substrate.

For example, the average surface roughness of commonly available polyethylene terephthalate (PET) is 8-12 root mean square (rms), where The achieved barrier properties are limited by the coverage of the surface plastic by the inorganic barrier material

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