Passivation Coatings for RF Power Devices

This Phase I project aims to increase the reliability of radio frequency (RF) devices used in accelerator facilities by reducing/eliminating corrosion and erosion produced from the high purity de-ionized water cooling systems. Although metal interconnects are the required for electrical and thermal performance, they susceptible to two major failure mechanisms, corrosion and erosion. Currently RF loads are purchased with anticorrosion coating, which must be re-applied as routine preventative maintenance. In addition to costs of coatings, accelerator down time is a significant expense. By reducing maintenance costs of current accelerator components, more resources can be focused on conducting research. This proposed approach will use atomic layer deposition (ALD) to deposit highly uniform ceramic thin films onto the metalized surfaces susceptible to the corrosion and erosion. Since ceramics are inert and hard, the ALD coating will provide corrosion resistance and erosion protection, thereby increasing reliability. The RF load surface will be treated with an organic self assembled monolayer (SAM) prior to ALD. The SAM will provide an ideal surface for ALD bonding, improve uniformity by masking surface defects in the metal, and provide compliance for coefficient of thermal expansion (CTE) mismatch. This innovative metal-organic-ceramic combination will extend the useable life of water cooled RF devices. Advanced Cooling Technologies Inc. has partnered with Altronic Research Inc., a RF load manufacturer, to ensure the proposed technology would be commercially applicable if a Phase III award was ultimately awarded. Commercial Applications and Other Benefits: Currently, corrosion and erosion are leading causes of failure in water cooled radio frequency devices. The coating process developed is this Phase I SBIR will reduce maintenance costs and downtime of accelerator facilities. This process is not only applicable to cooling loops in accelerator facilities, but all copper-water cooling systems that suffer from corrosion and erosion