An inkjet printhead heater chip has a silicon substrate with a heater stack formed of a plurality of thin film layers thereon for ejecting an ink drop during use. The thin film layers include: a thermal barrier layer on the silicon substrate; a resistor layer on the thermal barrier layer; a doped diamond-like carbon layer on the resistor layer; and a cavitation layer on the doped diamond-like carbon layer. The doped diamond-like carbon layer preferably includes silicon but may also include nitrogen, titanium, tantalum, combinations thereof or other. When it includes silicon, a preferred silicon concentration ranges from 20 to 25 atomic percent. A preferred cavitation layer includes an undoped diamond-like carbon, tantalum or titanium layer. The doped diamond-like carbon layer ranges in thickness from 500 to 3000 angstroms. The cavitation layer ranges from 500 to 6000 angstroms. Inkjet printheads and printers are also disclosed.