Hi guys, I am using a 0.15 um thick gold layer as heater over a waveguide. Unfortunately, I'm concerned with its long term stability. With dc current, it breaks after couple of hours (range between 10 and 30 mA). The reason for the break is electron migration, I guess. Does anyone have an idea how to implement a simple heater that will last for years?

And does anyone have experience with ac current application to overcome this electron migration? if yes, what ac frequency would you recommend?

Thanks in advance