CN1317736C - Monolithic fluid ejection device and method of making - Google Patents

Abstract

The invention provides a method for manufacturing a monolithic fluid ejection device. A patterned sacrificial layer is first formed on a first side of a substrate. Then, a patterned structure layer is formed on the substrate and covers the patterned sacrificial layer. Then, a patterned resistive layer is formed on the structural layer to form the heater. A patterned isolation layer is formed to cover the structural layer and has a heater contact window and a first opening. A patterned conductive layer is formed on the structural layer and connected with the heater through the heater contact window to form a signal transmission line. Then, a patterned passivation layer is formed on the substrate and covers the isolation layer and the conductive layer, and the patterned passivation layer has a signal transmission line contact window and a second opening corresponding to the first opening. Forming a fluid channel on the second side of the substrate to expose the sacrificial layer. Then, the sacrificial layer is removed to form a fluid cavity. Finally, the structural layer is etched along the second opening and the first opening, so that a jet hole communicated with the fluid cavity is formed.

Description

Monolithic fluid ejection device and method of making

technical field

The invention relates to a manufacturing method of a monolithic fluid ejection device, in particular to an improvement in the manufacturing process of a monolithic fluid ejection device.

Background technique

In the general single-chip fluid ejection device manufacturing process, since the micro-electromechanical and integrated circuit manufacturing plants are usually separate manufacturers, the integrated circuit device and micro-electro-mechanical components are divided into two independent manufacturing processes, so usually the integrated circuit manufacturing plant first After completing all the manufacturing processes of the integrated circuit device, it is then sent to the micro-electro-mechanical system manufacturing plant for subsequent fabrication of micro-electro-mechanical components.

However, in the manufacturing process of integrated circuit devices and micro-electromechanical components, the same thin-film manufacturing steps such as depositing metals, dielectric layers, and etching vias are often used, resulting in repeated increases in production costs and waste.

The known single-chip fluid ejection device uses part of the micro-electromechanical manufacturing process, so it does not need packaging technology, and can simultaneously form various components required by the ejection device on the chip, such as fluid chambers, heaters, drive circuits and nozzles. Holes, etc., have high manufacturing precision.

However, as far as the current manufacturing process of a single-chip fluid ejection device is concerned, semiconductor technology is used to complete the required components such as drive circuits and heaters, and then micro-electromechanical technology is used to complete the required components such as fluid chambers and nozzle holes. What Fig. 1A and 1B show is the sectional view of the manufacturing process of known monolithic fluid injection device, wherein Fig. 1A shows the front-end process that utilizes semiconductor technology to complete, and Fig. 1B shows the post-end process that utilizes microelectromechanical process to complete section craft. Referring to FIG. 1A, a substrate 10, such as a silicon substrate, is provided. A patterned sacrificial layer 20 is formed on the substrate 10 . Sacrificial layer 20 is made of silicon oxide. Next, a patterned structure layer 30 is formed on the substrate 10 and covers the patterned sacrificial layer 20 . The structural layer 30 may be formed of a silicon nitride layer formed by chemical vapor deposition (CVD). A patterned resistive layer 40 is formed on the structure layer 30 to serve as a heater. The resistance layer 40 is made of HfB ₂ , TaAl, TaN or TiN. A patterned isolation layer 50 is formed covering the structural layer 30 and having heater contact windows 45 . A patterned conductive layer is formed on the structure layer 30 and filled into the heater contact hole 45 to form a signal transmission line 62 . A protective layer 70 is formed on the substrate 10 , covering the isolation layer 50 and the conductive layer, and has a signal transmission line contact window 75 to expose the conductive layer to facilitate the subsequent packaging process.

Referring to FIG. 1B , a wet etching method, such as potassium hydroxide (KOH) solution, is used to etch to form a fluid channel 80 on the back surface of the substrate 10 and expose the sacrificial layer 20 . Next, the sacrificial layer 20 is etched with a hydrofluoric acid solution to form the fluid cavity 90 . Finally, after photoresist coating, exposure, and development processes, the structural layer 30 is etched to form the nozzle hole 95 communicating with the fluid chamber 90 . So far, the monolithic fluid ejection device is completed.

From the above process, it can be known that the formation of the nozzle hole 95 needs to at least penetrate the structure layer 30 , the isolation layer 50 and the protection layer 70 . In the previous process, the isolation layer 50 and the protection layer 70 will be etched when the signal transmission line 62 is connected to the heater 40 and when the contact window 75 of the signal transmission line is made. Therefore, if the etching of the isolation layer 50 and the protective layer 70 in the nozzle hole manufacturing process of the back-end process is combined into the front-end process, the nozzle hole manufacturing process of the back-end process can be reduced to only etching the structural layer 30 .

US Patent 6,102,530 shows a monolithic fluid ejection device fabricated by combining semiconductor technology and micro-electromechanical technology. Since the structural layer is suspended above the fluid cavity, strict control is required for the yield and durability of the product, which increases the difficulty of the manufacturing process.

Contents of the invention

In view of this, the object of the present invention is to provide a method for manufacturing a single-chip fluid ejection device, which combines some of the subsequent process steps into the front process, thereby reducing the number of spray hole processes in the latter stage and improving manufacturing efficiency.

According to the above purpose, the present invention provides a method for manufacturing a monolithic fluid ejection device, which includes the following steps: providing a substrate; forming a patterned sacrificial layer on the first surface of the substrate; forming a patterned structural layer on the substrate , and cover the patterned sacrificial layer; form a patterned resistance layer on the structural layer to form a heater; form a patterned isolation layer, cover the structural layer and have a heater contact window and a first opening, wherein the heater contact window at least exposes Part of the heater; forming a patterned conductive layer on the isolation layer, and connecting it to the heater through the heater contact window to form a signal transmission line; forming a patterned protective layer on the substrate, covering the isolation layer and the conductive layer, and having The signal transmission line contact window and the second opening corresponding to the first opening; forming a fluid channel on the second surface of the substrate, and the second surface is opposite to the first surface to expose the sacrificial layer; removing the sacrificial layer to form a fluid channel a chamber; and etching the structural layer along the second opening and the first opening to form an orifice communicating with the fluid chamber.

According to the above purpose, the present invention also provides a method for manufacturing a monolithic fluid ejection device, comprising the following steps: providing a substrate; forming a patterned sacrificial layer on the first surface of the substrate; forming a patterned structural layer on the substrate , and cover the patterned sacrificial layer; form a patterned resistance layer on the structural layer to form a heater; form a patterned isolation layer, cover the structural layer and have a heater contact window, wherein the heater contact window exposes at least part of the heater; forming a patterned conductive layer on the isolation layer, and connecting to the heater through the heater contact window to form a signal transmission line; forming a protective layer on the substrate, covering the isolation layer and the conductive layer; forming a fluid channel on the second side of the substrate surface, and the second surface is opposite to the first surface to expose the sacrificial layer; remove the sacrificial layer to form a fluid cavity; The etched protection layer simultaneously forms a signal transmission line contact window exposing at least part of the signal transmission line.

According to the above purpose, the present invention also provides a method for manufacturing a monolithic fluid ejection device, comprising the following steps: providing a substrate; forming a patterned sacrificial layer on the first surface of the substrate; forming a patterned structural layer on the substrate , and cover the patterned sacrificial layer; form a patterned resistance layer on the structural layer to form a heater; form a patterned isolation layer, cover the structural layer and have a heater contact window, wherein the heater contact window exposes at least part of the heater; forming a patterned conductive layer on the isolation layer, and filling the heater contact window to form a signal transmission line; forming a protective layer on the substrate, covering the isolation layer and the conductive layer; etching at least the protective layer and the isolation layer to form opening; forming a fluid channel on the second surface of the substrate, and the second surface is opposite to the first surface to expose the sacrificial layer; removing the sacrificial layer to form a fluid cavity; and etching the structural layer along the opening to form a fluid cavity Connected orifices.

In the above manufacturing method, the step of forming the opening may also include etching part of the structural layer

According to the above purpose, the present invention also provides a method for manufacturing a monolithic fluid ejection device, comprising the following steps: providing a substrate; forming a patterned sacrificial layer on the first surface of the substrate; forming a patterned structural layer on the substrate , and cover the patterned sacrificial layer; form a conductive layer on the structural layer; form a patterned resistance layer on the conductive layer to form a heater; pattern the conductive layer to form a signal transmission line; form a protective layer on the substrate Covering the structural layer, conductive layer and resistance layer; etching the protective layer to form an opening; forming a fluid channel on the second surface of the substrate, and the second surface is opposite to the first surface to expose the sacrificial layer; removing the sacrificial layer forming a fluid cavity; and etching the structure layer along the opening to form a spray hole communicating with the fluid cavity.

In the above manufacturing method of the present invention, the material of the isolation layer may be silicon oxide; the material of the protective layer may be silicon oxide, silicon nitride, silicon carbide or a composite stack thereof.

The present invention will be described in more detail below in conjunction with illustrations and preferred embodiments.

Description of drawings

What Fig. 1A and 1B show is the sectional view of the manufacturing process of known monolithic fluid ejection device, wherein Fig. 1A shows the front-end process that utilizes semiconductor technology to complete, and Fig. 1B shows the post-end process that utilizes MEMS process to complete section process;

What Fig. 2A to 2F shows is the sectional view of the manufacturing process of the monolithic fluid ejection device of the first preferred embodiment of the present invention, wherein Fig. 2A to 2D shows the front-end process that utilizes semiconductor technology to complete, and Fig. 2E and 2F show The post-end process completed by the use of micro-electromechanical technology;

What Fig. 3A to 3C shows is the sectional view of the manufacturing process of the monolithic fluid injection device of the second preferred embodiment of the present invention, wherein Fig. 3A shows the front-end process that utilizes semiconductor technology to complete, and Fig. 3B and 3C show The back-end process completed by micro-electromechanical technology;

What Fig. 4A and 4C show is the cross-sectional view of the manufacturing process of the monolithic fluid injection device of the third preferred embodiment of the present invention, wherein Fig. 4A shows the front-end process that utilizes semiconductor technology to complete, and Fig. 4B and 4C show The back-end process completed by MEMS technology; and

What Fig. 5A to 5D shows is the cross-sectional view of the manufacturing process of the monolithic fluid injection device of the fourth preferred embodiment of the present invention, wherein Fig. 5A and 5B have shown the front-end process that utilizes semiconductor technology to complete, and Fig. 5C and 5D show The post-end process completed by micro-electro-mechanical technology is shown.

Detailed ways

first embodiment

What Fig. 2A to 2F shows is the sectional view of the manufacturing process of the monolithic fluid injection device of the first embodiment of the present invention, wherein Fig. 2A to 2D shows the front-end process that utilizes semiconductor process to finish, and Fig. 2E and 2F show The post-end process completed by the use of micro-electromechanical technology. Referring to FIG. 2A , a patterned sacrificial layer 120 is formed on a substrate 100 such as a single crystal silicon substrate. The sacrificial layer 120 is composed of borophosphosilicate glass (BPSG), phosphosilicate glass (PSG) or other silicon oxide materials deposited by chemical vapor deposition (CVD). Next, a patterned structural layer 130 is conformally formed on the substrate 100 and covers the patterned sacrificial layer 120 . The structure layer 130 may be a silicon nitride layer formed by chemical vapor deposition (CVD). Then, a patterned resistive layer 140 is formed on the structure layer 130 to serve as a heater. The resistive layer 140 is formed of HfB ₂ , TaAl, TaN or other resistive materials by physical vapor deposition (PVD) such as evaporation, sputtering or reactive sputtering. Next, an isolation layer 150 is conformally formed and covers the structure layer 130 .

Referring to FIG. 2B , the isolation layer 150 is defined by photolithography and etching steps to form the heater contact window 145 and the first opening 195 a. Wherein the first opening 195a serves as the predecessor of the spray hole of the fluid ejection device.

Referring to FIG. 2C , a patterned conductive layer 162 such as Al, Cu, AlCu or other wire material is deposited by physical vapor deposition (PVD) and filled into the heater contact window 145 to form a signal transmission line 162 .

Referring to FIG. 2D , a protective layer 170 is formed on the substrate 100 and covers the isolation layer 150 and the signal transmission line 162 . Next, adopt photolithography and etching steps to define the protective layer 170 to form the signal transmission line contact window 175, so that the conductive layer is exposed for subsequent packaging operations; and the protective layer 170 is etched along the first opening 195a to form the second Opening 195b. Wherein the second opening 195b serves as the predecessor of the spray hole of the fluid ejection device.

Referring to FIG. 2E , wet etching is used to etch the backside of the substrate 100 to form fluid channels 180 and expose the sacrificial layer 120 . Next, the sacrificial layer 120 is etched to form the fluid cavity 190 .

Please refer to FIG. 2F, after photoresist coating, exposure, and development processes, the structural layer 130 is etched along the second opening 195b, preferably using plasma etching, chemical gas etching, reactive ion etching or laser Etching process to form the nozzle hole 195 communicating with the fluid cavity 190 . So far, the monolithic fluid ejection device is completed.

second embodiment

3A to 3C show cross-sectional views of the manufacturing process of the monolithic fluid ejection device according to the second embodiment of the present invention. 3A shows the front-end process completed by the semiconductor process, and FIGS. 3B and 3C show the back-end process completed by the micro-electromechanical process. Referring to FIG. 3A , a patterned sacrificial layer 120 is formed on a substrate 100 such as a single crystal silicon substrate. The sacrificial layer 120 is composed of borophosphosilicate glass (BPSG), phosphosilicate glass (PSG) or other silicon oxide materials deposited by chemical vapor deposition (CVD). Next, a patterned structural layer 130 is conformally formed on the substrate 100 and covers the patterned sacrificial layer 120 . The structure layer 130 may be formed of a silicon nitride layer formed by chemical vapor deposition (CVD). Then, a patterned resistive layer 140 is formed on the structure layer 130 to serve as a heater. The resistive layer 140 is formed of HfB ₂ , TaAl, TaN or other resistive materials by physical vapor deposition (PVD) such as evaporation, sputtering or reactive sputtering. Next, an isolation layer 150 is conformally formed and covers the structure layer 130 .

Next, the isolation layer 150 is defined by photolithography and etching steps to form the heater contact window 145 . Then, a patterned conductive layer 162 such as Al, Cu, AlCu or other wire material is deposited on the isolation layer 150 by physical vapor deposition (PVD) and filled into the heater contact window 145 to form the signal transmission line 162 . A passivation layer 170 is formed on the substrate 100 to cover the isolation layer 150 and the signal transmission line 162 .

Referring to FIG. 3B , the backside of the substrate 100 is etched to form a fluid channel 180 and expose the sacrificial layer 120 . Next, the sacrificial layer 120 is etched to form the fluid cavity 190 .

Please refer to FIG. 3C, after photoresist coating, exposure, and development steps, the protective layer 170 is etched and the signal transmission line 162 is used as an etching stop layer to form a signal transmission line contact window 175, so that the conductive layer is exposed. , to facilitate subsequent packaging operations. At the same time, the protective layer 170, the isolation layer 150 and the structural layer 130 are etched between the two heaters 140, preferably using plasma etching, chemical gas etching, reactive ion etching or laser etching process, so as to form a connection with the fluid chamber. The nozzle hole 195. Penetrating the structural layer 130 to form an injection hole 195 communicating with the fluid cavity 190 . So far, the monolithic fluid ejection device is completed.

third embodiment

4A to 4C show cross-sectional views of the manufacturing process of the monolithic fluid ejection device according to the third embodiment of the present invention. 4A shows the front-end process completed by the semiconductor process, and FIGS. 4B and 4C show the back-end process completed by the micro-electromechanical process. Referring to FIG. 4A , a patterned sacrificial layer 120 is formed on a substrate 100 such as a single crystal silicon substrate. The sacrificial layer 120 is composed of borophosphosilicate glass (BPSG), phosphosilicate glass (PSG) or other silicon oxide materials deposited by chemical vapor deposition (CVD). Next, a patterned structural layer 130 is conformally formed on the substrate 100 and covers the patterned sacrificial layer 120 . The structure layer 130 may be formed of a silicon nitride layer formed by chemical vapor deposition (CVD). Then, a patterned resistive layer 140 is formed on the structure layer 130 to serve as a heater. The resistive layer 140 is formed of HfB ₂ , TaAl, TaN or other resistive materials by physical vapor deposition (PVD) such as evaporation, sputtering or reactive sputtering. Next, an isolation layer 150 is conformally formed to cover the structural layer 130 . Next, the isolation layer 150 is defined by photolithography and etching steps to form the heater contact window 145 .

Then, a patterned conductive layer 162 such as Al, Cu, AlCu or other wire material is deposited on the isolation layer 150 by physical vapor deposition (PVD) and filled into the heater contact window 145 to form the signal transmission line 162 . A passivation layer 170 is formed on the substrate 100 to cover the isolation layer 150 and the signal transmission line 162 . Next, after photoresist coating, exposure, and development steps, the protective layer 170 is etched and the signal transmission line 162 is used as an etching stop layer to form a signal transmission line contact window 175, so that the conductive layer is exposed to facilitate Subsequent packaging operations. At the same time, the protection layer 170 and the isolation layer 150 are etched between the two heaters 140 to form an opening 195b. The opening 195b serves as the predecessor of the nozzle hole of the fluid ejection device.

Referring to FIG. 4B , the backside of the substrate 100 is etched by a wet etching method to form a fluid channel 180 and expose the sacrificial layer 120 . Next, the sacrificial layer 120 is etched to form the fluid cavity 190 .

Please refer to FIG. 4C, after photoresist coating, exposure, and development processes, the structural layer 130 is etched along the opening 195b, preferably by plasma etching, chemical gas etching, reactive ion etching or laser etching. process to form an orifice 195 communicating with the fluid chamber 190 . So far, the monolithic fluid ejection device is completed.

Fourth embodiment

5A to 5D show cross-sectional views of the manufacturing process of the monolithic fluid ejection device according to the fourth embodiment of the present invention. 5A and 5B show the front-end process completed by the semiconductor process, and FIGS. 5C and 5D show the back-end process completed by the micro-electromechanical process. Referring to FIG. 5A , a patterned sacrificial layer 120 is formed on a substrate 100 such as a single crystal silicon substrate. The sacrificial layer 120 is composed of borophosphosilicate glass (BPSG), phosphosilicate glass (PSG) or other silicon oxide materials deposited by chemical vapor deposition (CVD). Next, a patterned structural layer 130 is conformally formed on the substrate 100 and covers the patterned sacrificial layer 120 . The structural layer 130 may be formed of a silicon nitride layer formed by chemical vapor deposition (CVD). Then, a conductive layer 162 such as Al, Cu, AlCu or other wire material is deposited on the structure layer 130 by physical vapor deposition (PVD). A patterned resistive layer 140 is formed to serve as a heater. The resistive layer 140 is formed of HfB ₂ , TaAl, TaN or other resistive materials by physical vapor deposition (PVD) such as evaporation, sputtering or reactive sputtering. The conductive layer is patterned to form signal transmission lines 162 . Next, a protective layer 170 is formed on the substrate 100 to cover the resistive layer 140 and the signal transmission line 162 .

Please refer to FIG. 5B, after photoresist coating, exposure, and development steps, the protective layer 170 is etched and the signal transmission line 162 is used as an etching stop layer to form a contact window 175 of the signal transmission line, so that the conductive layer exposed to facilitate subsequent packaging operations. At the same time, the protection layer 170 is etched between the two heaters 140 to form an opening 195b. The opening 195b serves as the predecessor of the nozzle hole of the fluid ejection device.

Referring to FIG. 5C , the backside of the substrate 100 is etched by a wet etching method to form a fluid channel 180 and expose the sacrificial layer 120 . The sacrificial layer 120 is then etched to form the fluid cavity 190 .

Please refer to FIG. 5D, after photoresist coating, exposure, and development processes, the structural layer 130 is etched along the opening 195b, preferably by plasma etching, chemical gas etching, reactive ion etching or laser etching. process to form an orifice 195 communicating with the fluid chamber 190 . So far, the monolithic fluid ejection device is completed.

fifth embodiment

Referring to FIG. 5A again, a patterned sacrificial layer 120 is formed on a substrate 100 such as a single crystal silicon substrate. The sacrificial layer 120 is composed of borophosphosilicate glass (BPSG), phosphosilicate glass (PSG) or other silicon oxide materials deposited by chemical vapor deposition (CVD). Next, a patterned structural layer 130 is conformally formed on the substrate 100 and covers the patterned sacrificial layer 120 . The structural layer 130 may be formed of a silicon nitride layer formed by chemical vapor deposition (CVD). Then, a conductive layer 162 such as Al, Cu, AlCu or other wire material is deposited on the structure layer 130 by physical vapor deposition (PVD). A patterned resistive layer 140 is formed to serve as a heater. The resistive layer 140 is formed of HfB ₂ , TaAl, TaN or other resistive materials by physical vapor deposition (PVD) such as evaporation, sputtering or reactive sputtering. The conductive layer is patterned to form signal transmission lines 162 . Next, a protection layer 170 is formed on the substrate 100 to cover the resistor layer 140 and the signal transmission line 162 .

Next, the backside of the substrate 100 is etched by wet etching to form the fluid channel 180 and expose the sacrificial layer 120 . The sacrificial layer 120 is then etched to form the fluid cavity 190 .

Please refer to FIG. 5C again. After photoresist coating, exposure, and development steps, the protective layer 170 and the structural layer 130 are etched, preferably by plasma etching, chemical gas etching, reactive ion etching or Laser etching process, and the signal transmission line 162 is used as an etching stop layer to form a signal transmission line contact window 175, so that the conductive layer is exposed to facilitate subsequent packaging operations. Simultaneously, the protection layer 170 and the structural layer 130 are etched between the two heaters 140 to form the nozzle hole 195 communicating with the fluid cavity 190 . So far, the monolithic fluid ejection device is completed.

The feature and effect of the present invention are that the manufacturing process of a single nozzle hole is divided into two or more manufacturing processes and integrated into other processes so that the cost is dispersed in other processes.

Therefore, the present invention mainly integrates part of the MEMS process into the semiconductor process or integrates part of the semiconductor process into the MEMS process. It reduces the production cost of the overall process, and improves the defects produced in the process of making the nozzle hole, thereby improving the known process yield.

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

Claims (48)

1. A method for manufacturing a monolithic fluid injection device, comprising the following steps: provide the substrate; forming a patterned sacrificial layer on the first surface of the substrate; forming a patterned structure layer on the substrate and covering the patterned sacrificial layer; forming a patterned resistive layer on the structural layer to form a heater; forming a patterned isolation layer covering the structural layer, and having a heater contact window and a first opening, wherein the heater contact window exposes at least part of the heater; forming a patterned conductive layer on the isolation layer, and connecting with the heater through the heater contact window to form a signal transmission line; forming a patterned protective layer on the substrate, covering the isolation layer and the conductive layer, and having a signal transmission line contact window and a second opening corresponding to the first opening; forming a fluid channel on a second surface of the substrate to expose the sacrificial layer, wherein the second surface is opposite to the first surface; removing the sacrificial layer to form a fluid cavity; and The structural layer is etched along the second opening and the first opening, thereby forming an orifice communicating with the fluid cavity. 2. The method for manufacturing a monolithic fluid ejection device according to claim 1, wherein the step of forming the fluid channel is accomplished by wet etching. 3. The method for fabricating a monolithic fluid ejection device as claimed in claim 1, wherein the step of removing the sacrificial layer to form the fluid cavity is accomplished by wet etching. 4. The method of fabricating a monolithic fluid ejection device as claimed in claim 1, wherein the heater contact window and the first opening are formed simultaneously. 5 . The method for manufacturing a monolithic fluid ejection device as claimed in claim 1 , wherein the patterned protective layer further has a signal transmission line contact window, and the signal transmission line contact window exposes at least part of the signal transmission line. 6 . 6. The method of manufacturing a monolithic fluid ejection device as claimed in claim 5, wherein the signal transmission line contact window and the second opening are formed simultaneously. 7. The manufacturing method of a monolithic fluid ejection device according to claim 1, wherein the step of etching the structural layer adopts plasma etching, chemical gas etching, reactive ion etching or laser etching process. 8. The method of manufacturing a monolithic fluid ejection device according to claim 1, wherein the material of the sacrificial layer is borophosphosilicate glass, phosphosilicate glass or silicon oxide. 9. The method for fabricating a monolithic fluid ejection device as claimed in claim 1, wherein the material of the structural layer is silicon nitride. 10. The fabrication method of a monolithic fluid ejection device as claimed in claim 1, wherein the material of the resistive layer is HfB ₂ , TaAl, TaN or TiN. 11. The fabrication method of a monolithic fluid ejection device as claimed in claim 1, wherein the material of the conductive layer is Al, Cu or alloys thereof. 12. The method for fabricating a monolithic fluid ejection device as claimed in claim 1, wherein the material of the isolation layer is silicon oxide. 13. The method of manufacturing a monolithic fluid ejection device as claimed in claim 1, wherein the material of the protective layer is silicon oxide, silicon nitride, silicon carbide or a composite stack thereof. 14. A method of manufacturing a monolithic fluid ejection device, comprising the steps of: provide the substrate; forming a patterned sacrificial layer on the first surface of the substrate; forming a patterned structure layer on the substrate and covering the patterned sacrificial layer; forming a patterned resistive layer on the structural layer to form a heater; forming a patterned isolation layer covering the structural layer, and having a heater contact window, wherein the heater contact window exposes at least part of the heater; forming a patterned conductive layer on the isolation layer, and connecting with the heater through the heater contact window to form a signal transmission line; forming a protection layer on the substrate and covering the isolation layer and the conductive layer; forming a fluid channel on the second surface of the substrate, and the second surface is opposite to the first surface, so as to expose the sacrificial layer; removing the sacrificial layer to form a fluid cavity; and The protective layer, the isolation layer and the structural layer are etched to form a spray hole communicating with the fluid cavity, wherein the etched protective layer simultaneously forms a signal transmission line contact window exposing at least part of the signal transmission line. 15. The method for manufacturing a monolithic fluid ejection device as claimed in claim 14, wherein the step of forming the fluid channel is accomplished by wet etching. 16. The method for fabricating a monolithic fluid ejection device as claimed in claim 14, wherein the step of removing the sacrificial layer to form the fluid cavity is accomplished by wet etching. 17. The manufacturing method of a monolithic fluid ejection device according to claim 14, wherein the step of etching the structural layer adopts plasma etching, chemical gas etching, reactive ion etching or laser etching process. 18. The method of manufacturing a monolithic fluid ejection device as claimed in claim 14, wherein the material of the sacrificial layer is borophosphosilicate glass, phosphosilicate glass or silicon oxide. 19. The method of fabricating a monolithic fluid ejection device as claimed in claim 14, wherein the material of the structural layer is silicon nitride. 20. The method for fabricating a monolithic fluid ejection device as claimed in claim 14, wherein the material of the resistive layer is HfB ₂ , TaAl, TaN or TiN. 21. The method of manufacturing a monolithic fluid ejection device as claimed in claim 14, wherein the material of the conductive layer is Al, Cu or alloy materials thereof. 22. The method of fabricating a monolithic fluid ejection device as claimed in claim 14, wherein the material of the isolation layer is silicon oxide. 23. The method for manufacturing a monolithic fluid ejection device as claimed in claim 14, wherein the protective layer is made of silicon oxide, silicon nitride, silicon carbide or a composite stack thereof. 24. A method of making a monolithic fluid ejection device, comprising the steps of: provide the substrate; forming a patterned sacrificial layer on the first surface of the substrate; forming a patterned structure layer on the substrate and covering the patterned sacrificial layer; forming a patterned resistive layer on the structural layer to form a heater; forming a patterned isolation layer covering the structural layer, and having a heater contact window, wherein the heater contact window exposes at least part of the heater; forming a patterned conductive layer on the isolation layer, and filling the contact window of the heater to form a signal transmission line; forming a protective layer on the substrate and covering the isolation layer and the conductive layer; etching at least the protective layer and the isolation layer to form openings; forming a fluid channel on the second surface of the substrate, and the second surface is opposite to the first surface, so as to expose the sacrificial layer; removing the sacrificial layer to form a fluid chamber; and The structural layer is etched along the opening to form an orifice in communication with the fluid chamber. 25. The method for manufacturing a monolithic fluid ejection device as claimed in claim 24, wherein the step of forming the fluid channel is accomplished by wet etching. 26. The method for fabricating a monolithic fluid ejection device as claimed in claim 24, wherein the step of removing the sacrificial layer to form the fluid cavity is performed by wet etching. 27. The method for manufacturing a monolithic fluid ejection device as claimed in claim 24, wherein the etched protective layer further has a signal transmission line contact window, and the signal transmission line contact window exposes at least part of the signal transmission line. 28. The method of fabricating a monolithic fluid ejection device as claimed in claim 27, wherein the signal transmission line contact window and the opening are formed simultaneously. 29. The method of fabricating a monolithic fluid ejection device as claimed in claim 24, wherein the step of forming the opening further comprises etching a portion of the structural layer. 30. The method for manufacturing a monolithic fluid ejection device according to claim 24, wherein the step of etching the structural layer adopts plasma etching, chemical gas etching, reactive ion etching or laser etching process. 31. The method of manufacturing a monolithic fluid ejection device as claimed in claim 24, wherein the material of the sacrificial layer is borophosphosilicate glass, phosphosilicate glass or silicon oxide. 32. The method of fabricating a monolithic fluid ejection device as claimed in claim 24, wherein the material of the structural layer is silicon nitride. 33. The method for fabricating a monolithic fluid ejection device as claimed in claim 24, wherein the material of the resistive layer is HfB ₂ , TaAl, TaN or TiN. 34. The method for fabricating a monolithic fluid ejection device as claimed in claim 24, wherein the material of the conductive layer is Al, Cu or alloy materials thereof. 35. The method of fabricating a monolithic fluid ejection device as claimed in claim 24, wherein the material of the isolation layer is silicon oxide. 36. The method for manufacturing a monolithic fluid ejection device as claimed in claim 24, wherein the protective layer is made of silicon oxide, silicon nitride, silicon carbide or a composite stack thereof. 37. A method of making a monolithic fluid ejection device comprising the steps of: provide the substrate; forming a patterned sacrificial layer on the first surface of the substrate; forming a patterned structure layer on the substrate and covering the patterned sacrificial layer; forming a conductive layer on the structural layer; forming a patterned resistive layer on the conductive layer to form a heater; patterning the conductive layer to form signal transmission lines; forming a protective layer on the substrate and covering the structural layer, the conductive layer and the resistive layer; etching the protection layer to form an opening; forming a fluid channel on the second surface of the substrate, and the second surface is opposite to the first surface, so as to expose the sacrificial layer; removing the sacrificial layer to form a fluid chamber; and The structural layer is etched along the opening to form an orifice in communication with the fluid cavity. 38. The method for fabricating a monolithic fluid ejection device as claimed in claim 37, wherein the step of forming the fluid channel is accomplished by wet etching. 39. The method for fabricating a monolithic fluid ejection device as claimed in claim 37, wherein the step of removing the sacrificial layer to form the fluid cavity is performed by wet etching. 40. The method for manufacturing a monolithic fluid ejection device as claimed in claim 37, wherein the etched protective layer further has a signal transmission line contact window, and the signal transmission line contact window exposes at least part of the signal transmission line. 41. The method of fabricating a monolithic fluid ejection device according to claim 40, wherein the signal transmission line contact window and the opening are formed simultaneously. 42. The method for manufacturing a monolithic fluid ejection device according to claim 37, wherein the step of etching the structural layer adopts plasma etching, chemical gas etching, reactive ion etching or laser etching process. 43. The method of manufacturing a monolithic fluid ejection device as claimed in claim 37, wherein the material of the sacrificial layer is borophosphosilicate glass, phosphosilicate glass or silicon oxide. 44. The method of fabricating a monolithic fluid ejection device as claimed in claim 37, wherein the material of the structural layer is silicon nitride. 45. The method for fabricating a monolithic fluid ejection device as claimed in claim 37, wherein the material of the resistive layer is _HfB2 , TaAl, TaN or TiN. 46. The method of manufacturing a monolithic fluid ejection device as claimed in claim 37, wherein the material of the conductive layer is Al, Cu or alloy materials thereof. 47. The method for manufacturing a monolithic fluid ejection device as claimed in claim 37, wherein the protective layer is made of silicon oxide, silicon nitride, silicon carbide or a composite stack thereof. 48. A method of making a monolithic fluid ejection device comprising the steps of: provide the substrate; forming a patterned sacrificial layer on the first surface of the substrate; forming a patterned structure layer on the substrate and covering the patterned sacrificial layer; forming a conductive layer on the structural layer; forming a patterned resistive layer on the conductive layer to form a heater; patterning the conductive layer to form signal transmission lines; forming a protective layer on the substrate and covering the structural layer, the conductive layer and the resistive layer; forming a fluid channel on the second surface of the substrate, and the second surface is opposite to the first surface, so as to expose the sacrificial layer; removing the sacrificial layer to form a fluid chamber; and The protective layer and the structural layer are sequentially etched to form a spray hole communicating with the fluid cavity.

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