CN101062491A - Fluid ejection device and method of manufacturing the same - Google Patents

Abstract

A method of manufacturing a fluid ejection device. Firstly, a patterned sacrificial layer is formed on a substrate, and an electroplating starting layer is formed to at least cover the patterned sacrificial layer. Thereafter, a structural layer is formed on the plating start layer and the substrate, and the structural layer is patterned, thereby forming a nozzle hole. Then, the plating initiation layer in the nozzle hole is removed, and the sacrificial layer is removed to form a fluid cavity. And forming a structure protective layer for selectively coating the structure layer and the electroplating initial layer.

Description

Fluid ejection device and method of manufacturing the same

technical field

The present invention relates to a fluid ejection device and a manufacturing method thereof, and more particularly, to a microfluid ejection device and a manufacturing method thereof.

Background technique

Microfluid ejection devices have recently been widely used in the information industry, such as inkjet printers or similar devices. With the gradual development of micro system engineering, this fluid injection device has gradually been applied in many other fields, such as fuel injection system (fuel injection system), cell sorting (cell sorting), drug delivery system (drug delivery system) ), printing lithography (print lithography) and micro jet propulsion system (micro jet propulsion system), etc.

Figure 1 discloses a known fluid injection device 100, please refer to Figure 1, in the substrate 102, a fluid chamber 104 and a fluid channel 106 are formed, while an electroplating initiation layer 108 is formed on the substrate 102, and the electroplating initiation A structural layer 110 is formed on the layer 108, however, in this structure, a part of the plating initiation layer 108 will still be exposed in the nozzle hole 112 and the fluid chamber 104 to contact the filled ink, which will cause the plating initiation layer 108 Corroded by the ink, the ink deteriorates or the plating initiation layer 108 peels off.

Contents of the invention

According to the above problems, the object of the present invention is to provide a fluid ejection device and its manufacturing method, which can overcome the related problems caused by the corrosion of the plating initiation layer and the structural layer by ink, so as to obtain an inkjet device with higher stability and longer life. device.

Therefore, according to the above purpose, the present invention provides a method of manufacturing a fluid ejection device. First, a patterned sacrificial layer is formed on the substrate to form an electroplating initiation layer, at least covering the patterned sacrificial layer. Thereafter, a structural layer is formed on the electroplating initiation layer and the substrate, and the structural layer is patterned to form spray holes. Next, the electroplating initiation layer in the injection hole is removed, and the sacrificial layer is removed to form a fluid chamber. Subsequently, a structural protective layer that selectively covers the structural layer and the electroplating initiation layer is formed.

The invention provides a method for manufacturing a fluid ejection device. First, a patterned sacrificial layer is formed on the substrate to form an electroplating initial layer, at least covering the patterned sacrificial layer, wherein the electroplating initial layer is a titanium-copper composite layer. Thereafter, a structural layer is formed on the electroplating initiation layer and the substrate, and the structural layer is patterned to form spray holes. Next, the electroplating initiation layer in the injection hole is removed, and the back surface of the substrate is patterned to form a fluid channel to expose the sacrificial layer. Subsequently, the sacrificial layer is removed to form a fluid cavity, and the electroless structural protective layer covers the structural layer and the electroplating initiation layer, and fills the interface between the two, wherein the structural protection layer includes a direct contact structural layer and an electroplating initiation layer A nickel metal layer, and a gold metal layer on the nickel metal layer.

The present invention provides a fluid ejection device, comprising: a structural layer on a substrate to form a fluid chamber, the structural layer including an injection hole; an electroplating initiation layer located on the inner wall of the fluid chamber; and a structural protection with chemical stability layer, the structural protection layer covers the electroplating initiation layer, the structural layer and the interface between them.

Description of drawings

Figure 1 discloses a known fluid ejection device;

2A-2F disclose a method of manufacturing a fluid ejection device according to an embodiment of the present invention.

Explanation of reference signs of main components:

100～fluid ejection device; 102～substrate;

104～fluid cavity; 106～fluid channel;

108～Electroplating initial layer; 110～Structural layer;

112～nozzle hole; 200～substrate;

201～first side; 202～control grid;

204～gate dielectric layer; 206～first conductive layer;

207～source; 209～drain;

213～fluid control element; 215～heating element;

217～contact pad; 216～resistance layer;

218～second conductive layer; 220～passivation layer;

222～metal protection layer; 224～sacrifice layer;

226～electroplating initial layer; 228～photoresist layer;

230～structural layer; 232～nozzle hole;

234～fluid channel; 236～fluid cavity;

238～Structural protection layer; 240～The interface between the structural layer and the electroplating initial layer.

Detailed ways

The embodiments will be described in detail below as references to the present invention, and examples will be described with reference to the accompanying drawings. In the drawings or the description, the same reference numerals are used for similar or identical parts. In the drawings, the shapes or thicknesses of the embodiments may be exaggerated for simplification or convenient labeling. Parts illustrating each element will be described separately in the drawings, and it should be noted that elements not shown or described in the drawings may have various forms known to those skilled in the art. In addition, when a layer is described to be on a substrate or another layer, the layer may be directly on the substrate or another layer, or intervening layers may be present therebetween.

2A-2F are schematic cross-sectional process diagrams illustrating a fluid ejection device according to an embodiment of the present invention. First, referring to FIG. 2A , a substrate 200 is provided, and the substrate 200 includes silicon, glass, and/or other materials. Preferably, The substrate 200 is a silicon substrate. Subsequently, a control gate 202 composed of polysilicon or metal is formed on the substrate 200, and then a first dielectric layer 204 composed of silicon oxide, silicon nitride or silicon oxynitride is formed, Covering the control gate 202 and part of the substrate 200 . Subsequently, a first conductive layer 206 such as aluminum or copper is formed on the gate dielectric layer 204 and part of the substrate 200, wherein the first conductive layer 206 located on both sides of the control gate 202 can be used as a source 207 and a drain respectively. pole 209, and the control grid 202 and its associated circuits are the fluid control element 213 of the fluid ejection device of this embodiment.

Next, on part of the first conductive layer 206, the first dielectric layer 204 and the substrate 200, a second dielectric layer 208 composed of, for example, silicon oxide, silicon nitride or silicon oxynitride is formed. It should be noted that the second dielectric layer 208 Exposing part of the first conductive layer 206 and part of the drain electrode 209 as a plug (via), subsequently, forming a resistive layer 216 to cover part of the first conductive layer 206 and part of the source electrode 207, and then, forming a resistive layer 216 on the resistive layer 216 A second conductive layer 218 such as aluminum or copper is formed on it, wherein the second conductive layer 218 and the resistive layer 216 are closely connected. Subsequently, the second conductive layer 218 and the resistive layer 216 are patterned with, for example, a lithographic etching process, and then, the second conductive layer 218 in the heating element area is patterned to expose part of the resistive layer 216, so that the resistive layer 216 and the underlying The first conductive layer 206 constitutes a heating element 215 . Thereafter, a passivation layer 220 comprising, for example, SiC and SiN is formed on the second conductive layer 218 and the resistance layer 216, and a metal protective layer 222 composed of, for example, Ta is formed on the resistance layer 216 of the heating element 215, followed by patterning The passivation layer 220 thereby forms contact pads 217 .

Next, a patterned sacrificial layer 224 is formed on the first surface 201 of the substrate through, for example, deposition or coating, and performing a lithography definition step. In this embodiment, the first surface 201 is the fluid control element 213 same side. The sacrificial layer 224 may be composed of a dielectric layer such as oxide or a polymer layer such as photoresist and/or polymer, and the thickness of the sacrificial layer 224 may be between 2 μm˜100 μm.

Subsequently, referring to FIG. 2B , an electroplating initiation layer 226 is formed on the passivation layer 220 and the sacrificial layer 224 by evaporation or sputtering such as physical vapor deposition (PVD), and the electroplating initiation layer 226 needs to be in harmony with other The lower sacrificial layer 224 has good adhesion. Preferably, the electroplating initiation layer 226 can include a titanium metal layer and a copper metal layer on the titanium metal layer. The titanium metal is used to enhance the adhesion between the metal and the wafer surface, and the thickness is preferably For less than 1000 angstroms, copper metal is used as the plating initiation, and the thickness can be about 2000 angstroms to 8000 angstroms. In addition, the plating initiation layer 226 may further include a titanium metal layer and a nickel metal layer on the titanium metal layer.

Next, referring to FIG. 2C , a patterned photoresist layer 228 is formed by a spin coating method and a subsequent lithography process, and the patterned photoresist layer 228 covers the electroplating initiation layer 226. The position where the injection hole is planned to be formed, and the area other than the planned formation layer.

Then, use the electroplating method to form a structural layer 230 such as nickel on the electroplating initiation layer 226, because the part of the electroplating initiation layer 226 covered by the aforementioned photoresist layer 228 will not react in the electroplating solution, therefore, During the electroplating process, the structural layer 230 is formed on the portion of the electroplating initiation layer 226 not covered by the photoresist layer 228 , wherein the thickness of the structural layer 230 may be between 5 μm˜100 μm. Subsequently, referring to FIG. 2D , the above-mentioned photoresist layer 228 is removed by developing, stripper or plasma ashing, and after removing the above-mentioned photoresist layer 228, the structure layer 230 can be The spray hole 232 is formed in the spray hole 232, and then, the plating initiation layer 226 in the spray hole 232 can be removed by etching. It should be noted here that although the present invention discloses the above-mentioned method of removing the photoresist layer 228 to form the injection holes 232, the present invention is not limited thereto, and the present invention can also form the structural layer 230 first, and then perform lithography The etching step patterns the structural layer 230 to define orifices 232 . In a preferred embodiment of the present invention, the thickness of the structural layer is generally between 10 μm and 100 μm.

Next, please refer to FIG. 2E , perform, for example, a lithographic etching method, or a sandblasting method, to pattern the second surface 203 of the substrate, thereby forming a fluid channel 234, exposing the sacrificial layer 224, and then, through the fluid channel 234, use an etching The method removes the sacrificial layer 224 to form a fluid cavity 236 in communication with the fluid channel 234 . When the sacrificial layer 224 is made of polymer, the sacrificial layer 224 made of polymer may be removed by plasma ashing or stripper. The present invention is not limited thereto, that is, the order of the steps of forming the fluid channels 234 can be exchanged, for example, the sacrificial layer 224 can be removed through the spray holes 232 first, and then the fluid channels 234 can be formed on the second surface 203 of the substrate.

Next, referring to FIG. 2F , an electroless plating process is performed to form, for example, a structural protection layer 238 of 3000 angstroms to 8000 angstroms to selectively cover the structural layer 230, the exposed plating initiation layer 226 and/or the interface between the two 240 , it should be noted that the structural protection layer 238 must have good adhesion to the structural layer 230 and the electroplating initiation layer 226 . The process of forming the structural protection layer 238 may comprise the following steps: first, on the structural layer 230 and the exposed electroplating initiation layer 226, a layer of nickel metal layer is plated by an electroless plating method, and subsequently, on the nickel metal layer, an electroless plating method Plating a layer of gold metal layer, the nickel metal layer of the structural protection layer 238 has good adhesion to the structural layer 230, while the gold metal layer has good chemical stability.

Therefore, according to the above-mentioned embodiments of the present invention, the structural layer 230, the plating initiation layer 226 and/or the interface 240 of both are coated with a structural protection layer 238 having good chemical stability, so that the fluid cavity 236 and the fluid channel 234 The structure in the ink will not be eroded under long-term ink contact, and an inkjet device with higher stability and longer life is obtained.

Although the present invention has been disclosed with preferred embodiments, it is not intended to limit the present invention. Any skilled person can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope should be determined as defined by the appended claims.

Claims (20)

1. A method of manufacturing a fluid ejection device, comprising: provide the substrate; forming a patterned sacrificial layer on the substrate; forming an electroplating initiation layer covering at least the patterned sacrificial layer; forming a structural layer on the plating initiation layer and the substrate; patterning the structured layer to form orifices; removing the plating initiation layer in the nozzle hole; removing the sacrificial layer to form a fluid chamber; and A structural protection layer selectively covering the structural layer and the electroplating initiation layer is formed. 2. The method of manufacturing a fluid ejection device as claimed in claim 1, wherein the structural protection layer is chemically stable. 3. The method of manufacturing a fluid ejection device as claimed in claim 1, wherein the electroplating initiation layer comprises a titanium metal layer and a copper metal layer on the titanium metal layer. 4. The method of manufacturing a fluid ejection device as claimed in claim 1, wherein the structural protection layer has good adhesion to the structural layer and the plating initiation layer. 5 . The method of manufacturing a fluid ejection device as claimed in claim 1 , wherein the structural protection layer comprises a nickel metal layer directly contacting the structural layer and the electroplating initiation layer, and a gold metal layer on the nickel metal layer. 6 . The method for manufacturing a fluid ejection device as claimed in claim 1 , wherein the step of forming a structural protective layer selectively covering the structural layer and the plating initiation layer is an electroless plating process. 7 . 7. The method of manufacturing a fluid ejection device as claimed in claim 1, wherein the structural layer is made of nickel metal. 8. The method of manufacturing a fluid ejection device according to claim 1, further comprising patterning the substrate to form a fluid channel communicating with the fluid cavity. 9. The method of manufacturing a fluid ejection device according to claim 1, before the step of forming a patterned sacrificial layer on the substrate, further comprising forming a fluid driving element on the substrate. 10. A method of manufacturing a fluid ejection device, comprising: provide the substrate; forming a patterned sacrificial layer on the substrate; forming an electroplating initiation layer, covering at least the patterned sacrificial layer, wherein the electroplating initiation layer is a titanium-copper composite layer; electroplating a structural layer on the electroplating initiation layer and the substrate; patterning the structured layer to form orifices; removing the electroplating initiation layer in the spray hole; patterning the substrate to form fluidic channels exposing the sacrificial layer; removing the sacrificial layer, thereby forming a fluid cavity; and An electroless structural protective layer, the structural protective layer covers the structural layer and the electroplating initiation layer, and fills the interface between the two, wherein the structural protective layer includes nickel directly contacting the structural layer and the electroplating initiation layer A metal layer, and a gold metal layer on the nickel metal layer. 11. The method of manufacturing a fluid ejection device as claimed in claim 10, wherein the patterned sacrificial layer is made of polymer. 12. The method of manufacturing a fluid ejection device as claimed in claim 10, wherein the structural layer is made of nickel metal. 13. A fluid ejection device comprising: Substrate; a structural layer on the substrate to form a fluid cavity, wherein the structural layer includes an orifice; a plating initiation layer on the inner wall of the fluid chamber; and The structure protection layer has chemical stability, and the structure protection layer covers the electroplating initiation layer, the structure layer and the interface between them. 14. The fluid ejection device of claim 13, wherein the plating initiation layer comprises a titanium metal layer and a copper metal layer on the titanium metal layer. 15. The fluid ejection device of claim 13, wherein the structural protection layer has good adhesion to the structural layer and the plating initiation layer. 16. The fluid ejection device of claim 13, wherein the structural protection layer comprises a nickel metal layer directly contacting the structural layer and the plating initiation layer, and a gold metal layer on the nickel metal layer. 17. The fluid ejection device of claim 13, wherein the structural layer is comprised of nickel metal. 18. The fluid ejection device of claim 13, wherein the substrate is a silicon substrate. 19. The fluid ejection device of claim 13, further comprising a fluid drive device on the substrate. 20. The fluid ejection device of claim 13, further comprising a fluid channel in the substrate communicating with the fluid cavity.

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