Printhead for thermal ink jet devices

摘要

The efficiency of a thermal ink jet printhead is improved by providing a thermally grown field oxide layer and a deposited oxide layer, the two combined layers providing thermal insulation between a resistor layer and a silicon substrate. In a preferred embodiment, zirconium diboride is sputtered in the presence of oxygen to form a thin field oxide layer on a field oxide layer grown on the surface of the silicon substrate. At a predetermined time, during the sputtering process, oxygen is removed and the sputtering continues to form a conductive ZrB2 layer. The combined thickness of the two oxide layers provides the required thermal isolation between silicon substrate and heater resistor while the thermally grown field oxide layer enables the closer packing of resistor transistor drive circuits.