Low ejection energy micro-fluid ejection heads
View Patent ↗A micro-fluid ejection device structure and method therefor having improved low energy design. The devices include a semiconductor substrate and an insulating layer deposited on the semiconductor substrate. A plurality of heater resistors are formed on the insulating layer from a resistive layer selected from the group consisting of TaAl, Ta2N, TaAl(O,N), TaAlSi, Ti(N,O), WSi(O,N), TaAlN, and TaAl/TaAlN. A sacrificial layer selected from an oxidizable metal and having a thickness ranging from about 500 to about 5000 Angstroms is deposited on the plurality of heater resistors. Electrodes are formed on the sacrificial layer from a first metal conductive layer to provide anode and cathode connections to the plurality of heater resistors. The sacrificial layer is oxidized in a plasma oxidation process to provide a fluid contact layer on the plurality of heater resistors.
1. A method of making a micro-fluid ejection device structure, comprising:
forming a resistive layer on a substrate, the resistive layer having a thickness ranging from 500 to about 1,500 Angstroms;
forming a sacrificial film layer adjacent to the resistive layer, the sacrificial film layer having a thickness ranging from about 500 to about 5,000 Angstroms;
forming a first metal conductive layer adjacent to the sacrificial film layer and etching the first metal conductive layer to define ground and address electrodes and a plurality of heater resistors there between, including exposing a surface of the sacrificial film layer on the plurality of heater resistors between the electrodes; and
oxidizing the exposed surface of the sacrificial film layer to define a protective barrier on the plurality of heater resistors.
2. The method of claim 1 , further including forming an insulating layer between the substrate and the resistive layer in a thickness ranging from about 8,000 to about 30,000 Angstroms.
3. The method of claim 1 , further including forming a dielectric layer adjacent to the electrodes and the exposed surface of the sacrificial film layer.
4. The method of claim 3 , further including etching the dielectric layer to reveal the sacrificial film layer on the plurality of heater resistors between the electrodes.
5. The method of claim 3 , wherein the forming the dielectric layer includes depositing the dielectric layer in a thickness ranging from about 1,000 to 8,000 Angstroms.
6. The method of claim 1 , further including forming or attaching a nozzle plate on the substrate having a plurality of nozzle holes corresponding to the plurality of heater resistors, wherein the nozzle plate defines a fluid chamber for fluid that exists adjacent the oxidized said exposed surface of the sacrificial film layer during use.
7. The method of claim 6 , further including forming a second metal conductive layer on the substrate for the attaching the nozzle plate.
8. The method of claim 1 , wherein the forming the first metal conductive layer further includes depositing a metal selected from aluminum, copper, and gold.
9. The method of claim 1 , wherein the forming the resistive layer further includes depositing one of TaAl, Ta 2 N, TaAl(O,N), TaAlSi, Ti(N,O), WSi(O,N), TaAlN, and TaAl/TaAlN.
10. The method of claim 1 , wherein the forming the sacrificial layer further includes depositing one of tantalum (Ta), and titanium (Ti).
11. The method of claim 3 , wherein the forming the dielectric layer further includes depositing one of diamond-like carbon (DLC), doped-DLC, silicon nitride, and silicon dioxide.
12. The method of claim 1 , wherein portions of the sacrificial layer underlying the electrodes remain substantially conductive after the oxidizing the exposed surface of the sacrificial film layer.
13. A method of making a micro-fluid ejection device structure, comprising:
forming a resistive layer on a substrate;
forming a sacrificial film layer adjacent to the resistive layer;
forming a metal conductive layer adjacent to the sacrificial film layer;
etching the metal conductive layer to define ground and power electrodes and a plurality of heater resistors there between, including exposing a surface of the sacrificial film layer on the plurality of heater resistors between the electrodes; and
oxidizing the exposed surface of the sacrificial film layer to define a protective barrier on the plurality of heater resistors.
14. The method of claim 13 , further including forming an insulating layer between the substrate and the resistive layer.
15. The method of claim 13 , further including forming a dielectric layer adjacent to the electrodes.
16. The method of claim 15 , further including etching the dielectric layer to reveal the sacrificial film layer on the plurality of heater resistors between the electrodes.
17. The method of claim 13 , further including forming or attaching a nozzle plate on the substrate having a plurality of nozzle holes corresponding to the plurality of heater resistors, wherein the nozzle plate defines a fluid chamber for fluid that exists adjacent the oxidized said exposed surface of the sacrificial film layer during use.
18. The method of claim 17 , further including forming a second metal conductive layer on the substrate for the attaching the nozzle plate.
19. The method of claim 13 , wherein the forming the sacrificial layer further includes depositing one of tantalum (Ta), and titanium (Ti).
20. The method of claim 13 , wherein the forming the sacrificial film layer includes depositing the sacrificial film layer in a thickness ranging from about 500 to 5,000 Angstroms.