Fluid injection apparatus and fabrication method thereof

Abstract

A method for forming a fluid injection apparatus is disclosed. A patterned sacrificial layer is formed overlying a substrate. A electroplate seed layer is formed on the patterned sacrificial layer. A structural layer is formed overlying the electroplate seed layer and the substrate. The structural layer is patterned to form a nozzle. The electroplate seed layer in the nozzle is removed. The sacrificial layer is removed to form a fluid chamber. A protective layer is formed to selectively cover the structural layer and the electroplate seed layer.

1 . A method for forming a fluid injection apparatus, comprising:
 providing a substrate;   forming a patterned sacrificial layer overlying the substrate;   forming a electroplate seed layer, at least covering the patterned sacrificial layer;   forming a structural layer overlying the electroplate seed layer and the substrate;   patterning the structural layer to form a nozzle;   removing the electroplate seed layer in the nozzle;   removing the sacrificial layer to form a fluid chamber; and   forming a protective layer, selectively covering the structural layer and the electroplate seed layer.   
   
   
       2 . The method for forming a fluid injection apparatus as claimed in  claim 1 , wherein the protective layer has chemical resistance. 
   
   
       3 . The method for forming a fluid injection apparatus as claimed in  claim 1 , wherein the electroplate seed layer comprising a Ti layer and a Cu layer overlying the Ti layer. 
   
   
       4 . The method for forming a fluid injection apparatus as claimed in  claim 1 , wherein the protective layer has good adhesion to the structural layer and the electroplate seed layer. 
   
   
       5 . The method for forming a fluid injection apparatus as claimed in  claim 1 , wherein the protective layer comprises a nickel layer directly contacting the structural layer and the electroplate seed layer, and a gold layer overlying the nickel layer. 
   
   
       6 . The method for forming a fluid injection apparatus as claimed in  claim 1 , wherein forming a protective layer, selectively covering the structural layer and the electroplate seed layer is accomplished by electroless plating. 
   
   
       7 . The method for forming a fluid injection apparatus as claimed in  claim 1 , wherein the structural layer comprises nickel. 
   
   
       8 . The method for forming a fluid injection apparatus as claimed in  claim 1 , further comprising patterning the substrate to form a manifold connecting the fluid chamber. 
   
   
       9 . The method for forming a fluid injection apparatus as claimed in  claim 1 , before forming a patterned sacrificial layer overlying the substrate, further comprising forming a fluid driving device overlying the substrate. 
   
   
       10 . A method for forming a fluid injection apparatus, comprising:
 providing a substrate;   forming a patterned sacrificial layer overlying the substrate;   forming a electroplate seed layer, at least covering the patterned sacrificial layer;   electroplating a structural layer overlying the electroplate seed layer and the substrate;   patterning the structural layer to form a nozzle;   removing the electroplate seed layer in the nozzle;   patterning the substrate to form a manifold exposing the sacrificial layer;   removing the sacrificial layer to form a fluid chamber; and   electroless plating a protective layer, covering the structural layer and the electroplate seed layer, and filling a interface between the structural layer and the electroplate seed layer, wherein the protective layer comprises a nickel layer directly contacting the structural layer and the electroplate seed layer, and a gold layer overlying the nickel layer.   
   
   
       11 . The method for forming a fluid injection apparatus as claimed in  claim 10 , wherein the patterned sacrificial layer comprises polymer. 
   
   
       12 . The method for forming a fluid injection apparatus as claimed in  claim 10 , wherein the structural layer comprises nickel. 
   
   
       13 . A fluid injection apparatus, comprising:
 a substrate;   a structural layer disposed overlying the substrate to form a fluid chamber, wherein the structural layer comprises a nozzle;   a electroplate seed layer disposed on an inner sidewall of the fluid chamber; and   a protective layer having chemical resistance covering the electroplate seed layer, the structural layer and a interface therebetween.   
   
   
       14 . The fluid injection apparatus as claimed in  claim 13 , wherein the electroplate seed layer comprises a Ti layer and a Cu layer overlying the Ti layer. 
   
   
       15 . The fluid injection apparatus as claimed in  claim 13 , wherein the protective layer has good adhesion to the structural layer and the electroplate seed layer. 
   
   
       16 . The fluid injection apparatus as claimed in  claim 13 , wherein the protective layer comprises a nickel layer directly contacting the structural layer and the electroplate seed layer, and a gold layer overlying the nickel layer. 
   
   
       17 . The fluid injection apparatus as claimed in  claim 13 , wherein the structural layer comprises nickel. 
   
   
       18 . The fluid injection apparatus as claimed in  claim 13 , wherein the substrate is a silicon substrate. 
   
   
       19 . The fluid injection apparatus as claimed in  claim 13 , further comprising a fluid driving device disposed overlying the substrate. 
   
   
       20 . The fluid injection apparatus as claimed in  claim 13 , further comprising a manifold disposed in the substrate, connecting the fluid chamber.