Method for making a thin film resistor
View Patent ↗A process for making a fluid ejector head for a micro-fluid ejection device. In one embodiment, the process comprises depositing a thin film resistive layer on a substrate to provide a plurality of thin film heaters. The thin film resistive layer comprises a tantalum-aluminum-nitride material consisting essentially of AlN, TaN, and TaAl alloys, and containing from about 30 to about 70 atomic % tantalum, from about 10 to about 40 atomic % aluminum and from about 5 to about 30 atomic % nitrogen.
1. A method for making a thin film resistor comprising:
heating a substrate to a temperature ranging from above about room temperature to about 350° C.
reactive sputtering a tantalum aluminum alloy target containing from about 50 to about 60 atomic % tantalum and from about 40 to about 50 atomic % aluminum onto the substrate;
providing a flow of nitrogen gas and a flow of argon gas during the sputtering wherein a flow rate ratio of nitrogen to argon ranges from about 0.1:1 to about 0.4:1; and
terminating the sputtering when the thin film resistor is deposited on the substrate with a thickness ranging from about 300 to about 3000 Angstroms, wherein the thin film resistor comprises a TaAlN alloy containing from about from about 30 to about 70 atomic % tantalum, from about 10 to about 40 atomic % aluminum and from about 5 to about 30 atomic % nitrogen, and the resistor has a substantially uniform sheet resistance with respect to the substrate.
2. The method of claim 1 wherein the reactive sputtering is conducted with a power ranging from about 40 to about 200 kilowatts per square meter.
3. The method of claim 1 wherein the reactive sputtering is conducted at a pressure ranging from about 1 to about 25 millitorrs.
4. The method of claim 1 , further comprising heating the substrate to a temperature in the range of from about 100 to about 300° C.