ALD on Polymers

Polymers are pervasive because of their flexibility, light weight and low cost. Many polymer properties could be enhanced by the addition of an inorganic coating on their surface. This inorganic film could serve as a gas diffusion barrier for various packaging applications. The inorganic layer could also serve to protect the underlying polymer and give the polymer higher strength. Unfortunately, inorganic layers are difficult to deposit on polymers because the deposition of inorganics is usually performed at temperatures above the melting temperature of the polymer.

Our recent work has shown that Al2O3 ALD using Al(CH3)3 and H2O can deposit an Al2O3 film on polymers at fairly low temperatures below the polymer melting temperature. This Al2O3 coating serves as a gas diffusion barrier for the polymer. The Al2O3 film may also act as an adhesion layer for the deposition of other materials. These Al2O3 adhesion layers may be useful to facilitate the deposition of diffusion barriers on low-k dielectrics for backend interconnects. The accompanying figure shows quartz crystal microbalance (QCM) and x-ray fluorescence results for Al2O3 ALD on the lowk SiLK polymer [1].

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