JP2010005795A - Method of manufacturing liquid jet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple method for preventing an occurrence of a notch at a feed port in a liquid jet recording head forming a feed port by dry etching. <P>SOLUTION: A Ta film which is a protection film and a metallic film is used as an etching stop layer of a feed port instead of a conventional thermal oxidation film. Thus, the protection film comprised of Ta being a metal is adopted as the etching stop layer without introducing a new metallic film as the etching stop layer, so that an occurrence of a notch is prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a liquid discharge recording head.

  Conventionally, Patent Document 1 or Patent Document 2 discloses an ink jet recording head of a type that discharges ink above an ink discharge pressure generating element, that is, a so-called side shooter type ink jet recording head. The ink jet recording head disclosed in Patent Document 1 or Patent Document 2 is provided with an ink supply port composed of a through-hole on a substrate on which an ink discharge pressure generating element is formed, and the back surface of the surface on which the ink discharge pressure generating element is formed. A method of supplying more ink is employed.

  In this case, when ink is supplied from the ink discharge pressure generating element forming surface (ink discharge port forming surface) side, an ink supply member exists between the ink discharge port and a recording medium such as paper or cloth. . However, since it is difficult to make the ink supply member thin, the distance between the ink discharge port and the recording medium cannot be shortened, and sufficient image quality cannot be obtained due to a decrease in landing position accuracy.

  Recent inkjet recording heads are required to open with high accuracy while suppressing variations in the dimensions of the supply port as performance increases. Processing the supply port with high accuracy leads to suppressing variation in the distance from the end of the supply port to the heater, which greatly affects the flow resistance of the discharged liquid. If it is possible to process the supply port with high accuracy, the degree of freedom in designing the flow path portion increases, which is very advantageous for realizing an ink jet recording head with excellent discharge performance.

  One means for opening the supply port with high accuracy is dry etching. Among them, if anisotropic dry etching is used, high-precision processing is possible and fine processing is possible.

  On the other hand, in recent years, in the field of MEMS (Micro Electro Mechanical Systems), the Bosch process has attracted attention as a silicon digging technique. This is a kind of RIE method (reactive ion etching method) in which protective film formation on a wall surface and dry etching are alternately repeated.

  When the supply port is formed by dry etching, an etching stop layer is generally provided on one side of the silicon substrate, an etching mask is provided on the other side of the substrate, and etching is performed so as to penetrate the substrate. At this time, since the selection ratio with silicon is high and the process is easy, a silicon-based insulating film used as an insulating layer for wiring or the like is often used as an etching stop layer.

  Patent Document 3 discloses a technique for forming a supply port using the above-described Bosch process as a silicon deep digging technique. FIG. 11A is a schematic plan view for explaining the configuration of the ink jet recording head when the Bosch process disclosed in Patent Document 3 is adopted in the ink jet recording head, and FIG. FIG. 11 shows a schematic sectional view of the part.

  Hereinafter, the configuration of the ink jet recording head when the Bosch process disclosed in Patent Document 3 is employed, using a schematic process cross-sectional view using the cross section of the aa portion of FIG. The manufacturing method will be described.

  A thermal oxide film 450, a heater 300 serving as an ink discharge pressure generating element, a silicon nitride film 200 serving as a protective film, and a Ta (tantalum) film 100 are formed on the silicon substrate 400, and a position where an ink supply port is to be formed in the future is protected. The state in which the silicon nitride film 200 and the Ta film 100 to be films are removed is shown in FIG. 11 and FIG.

  Thereafter, the protective resist 500 is applied to the surface on which the flow path is formed, and the back surface resist is formed on the surface where the supply port etching is started. Next, the backside resist at the portion where the supply port is formed is removed to form a backside resist pattern 600 (see FIG. 13B).

  Thereafter, using the back resist pattern 600 as a mask, the silicon substrate 400 is etched using a Bosch process until the thermal oxide film 450 as an etching stop layer is exposed, thereby forming a supply port 700 (see FIG. 13 (3)). ).

  Next, a state where the thermal oxide film 450 exposed at the supply port 700 is removed by using a Bosch process is shown (see FIG. 13 (4)).

  Next, the protective resist 500 and the back surface resist pattern 600 are peeled and removed (see FIG. 13 (5)). A general resist stripping solution was used for stripping.

  After penetrating the supply port, the nozzle plate 800 is bonded to form an ink jet recording head (see FIG. 13 (6)). Here, an example is shown in which a polyimide film is processed with a laser and bonded with an adhesive.

  However, when dry etching is performed using a silicon-based insulating film as an etching stop layer, the end portion on the etching stop layer side of the supply port shown in FIG. 12 is etched to form a groove-shaped “notch” shape. May be.

  This is because, as explained in Non-Patent Document 1, when the etching stop layer is positively charged, the trajectory of positive ions contributing to etching is bent, and etching is performed in the direction of the side wall in the vicinity of the insulating film. The cause is to proceed to. Notches occur irregularly and it is very difficult to control their shape and dimensions. In order to prevent this, there is a technique for controlling the substrate bias. However, in general, such an etching condition has a slow rate, which decreases productivity.

  Even when an insulating film is used for the etching stop layer, such a phenomenon can be prevented from occurring if the etching is stopped as soon as the etching stop layer is exposed at the supply port. However, there is an etching rate difference between the central portion and the peripheral portion of the supply port. When repeated etching is performed, the etching rate changes every time, or the etching rate is different between the central portion and the peripheral portion of the substrate. There are cases. Therefore, in order to form the supply port that penetrates the substrate, it is necessary to perform the etching time longer than the calculated value (overetching). Therefore, when an etching stop layer made of an insulating material such as SiN exposed at the supply port is used, it is difficult to prevent the etching stop layer from being charged.

  On the other hand, in Patent Document 4, in order to avoid the formation of a notch when forming an opening penetrating the substrate, the entire surface on the side opposite to the surface where etching of the substrate is started is made of a conductive layer. Forming a stop layer is disclosed.

Patent Document 5 discloses a structure in which two protective films are provided on a heating resistor for a substrate used in an ink jet recording head. In Patent Document 5, a silicon-based protective film such as Si ₃ N ₄ is used immediately above the heating resistor for the purpose of maintaining the insulation between the common electrode and the individual electrode, and a relatively sticky metal or the like is formed thereon. It is disclosed to use a protective film such as Ta having mechanical strength.
Japanese Patent Laid-Open No. 62-264957 USP 4789425 specification JP 2003-53979 A JP 2004-152967 A JP 59-194866 A Latest Trends in Etching Technology, p1-3, Seiji Samukawa, July 1, 2002, ED Research

  On the other hand, in order to prevent the formation of the notch, there is a method of forming a conductive layer on the entire surface of the substrate as an etching stop layer disclosed in Patent Document 4.

  However, the etching stop layer is a film that needs to be provided in a region where the supply port is formed, and a film that needs to be removed after the etching of the silicon substrate is completed. For this reason, when an etching stop layer made of a conductive material is newly provided, there are problems such as an increase in the number of processes and positional accuracy.

  For this reason, there is an urgent need to develop a technique that reduces the increase in the number of processes and prevents the formation of notches.

The present invention relates to a liquid discharge pressure generating element provided on a silicon-based insulating film provided on a silicon substrate, a flow path provided on the liquid discharge pressure generating element, and a liquid in the flow path. A liquid discharge recording head having a supply port penetrating a substrate for supplying
Forming a silicon-based insulating film in a region for forming the liquid discharge pressure generating element;
Providing a liquid discharge pressure generating element on a silicon-based insulating film;
Forming a first protective film made of a silicon-based insulating film on the liquid discharge pressure generating element;
Removing at least a first protective film in a region to be an end of a region where a future supply port of the silicon substrate is formed;
Thereafter, a step of forming a second protective film made of a metal material,
Forming a supply port penetrating the silicon substrate using reactive ion etching;
Thereafter, a step of removing the first protective film that becomes an etching stop layer of reactive ion etching exposed to the supply port, or the first protective film and the second protective film,
And a step of forming a nozzle plate having a discharge port for forming a flow path so as to cover the supply port.

  According to the present invention, it is possible to open an ink supply port that greatly affects the ejection characteristics of an ink jet recording head with high accuracy and high productivity.

  Since the ink jet recording head uses a liquid other than ink, for example, an organic EL, it is hereinafter referred to as a liquid discharge recording head.

  The inventor paid attention to a protective film provided on a liquid discharge pressure generating element (hereinafter referred to as a heater). The protective film includes a silicon-based protective film such as an insulating silicon nitride film for the purpose of maintaining insulation between the individual electrode and the common electrode, and a relatively sticky and mechanically strong Ta film provided thereon. There is a protective film made of a metal material. Ta (tantalum) is used as a protective film for a heater in a liquid discharge recording head because it is sticky and has mechanical strength.

Further, it has been noted that for Ta dry etching, a general etching gas such as CF ₄ that is also used for etching a silicon-based insulating film can be used.

  The silicon-based insulating film is a generic term for silicon-based insulating films such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film.

  In the present invention, Ta, which is a protective film and a metal film, is used as an etching stop layer for the supply port instead of the conventional thermal oxide film. Therefore, it is possible to adopt a protective film made of Ta, which is a metal, as an etching stop layer without introducing a new metal film as an etching stop layer, so that the generation of notches can be prevented.

  At this time, the entire etching stop layer does not need to be a Ta film, and the etching stop layer exposed in the vicinity of the side wall of the supply port (outer edge portion of the supply port) may be a Ta film, and is exposed at the center of the supply port. The etched stop layer may be a silicon-based insulating film. The reason is that even if the insulating film exposed at the center of the supply port is charged and the trajectory of positive ions contributing to the etching is bent, the notch is not formed unless the bent positive ions reach the side wall of the supply port. Because.

  By using the Ta film used as the protective film as an etching stop layer, a new metal film can be omitted, and the number of processes does not increase.

  A first embodiment of a liquid discharge recording head of the present invention will be described with reference to FIGS.

  FIG. 2B shows a plan view of a state in which a protective film made of Ta which also serves as a protective film for the heater and an etching stop layer is formed. FIG. 2A shows a cross section taken along the line aa in FIG. It is shown. Further, FIG. 1 shows a schematic perspective view of the section aa in FIG. 2B in a state in which the supply port is formed.

  FIG. 3 is a schematic process cross-sectional view illustrating a manufacturing method of the liquid discharge recording head according to the first embodiment, taken along a line aa in FIG.

  A thermal oxide film 450 is formed in a region on the silicon substrate 400 where the heater is formed, and the heater 300 is formed on the thermal oxide film 450. A silicon nitride film 200 is formed so as to cover the heater 300 and removed so that the surface of the silicon substrate 400 in a region where a future supply port of the silicon nitride film 200 will be formed is exposed, and a Ta film 100 is formed on the entire surface of the silicon. (See FIGS. 2A and 2B).

  This forms a silicon nitride film (not shown) on the silicon substrate 400, then removes the silicon nitride film in a region where a future supply port will be formed, and exposes the silicon substrate in a region where a heater will be formed in the future. Next, the exposed silicon substrate is oxidized using a thermal oxidation method to form a thermal oxide film 450. Next, after forming the heater 300 on the thermal oxide film, the silicon nitride film 200 is formed. Thereafter, a region of the silicon nitride film 200 where a future supply port is to be formed is removed using a normal photolithography method and a dry etching method, and then the Ta film 100 is formed.

  FIG. 1 shows a state where the silicon substrate is further etched away and a supply port is formed.

  1 and 2 show a structure in which the thermal oxide film 450 is provided in a region where the heater 300 will be formed in the future, the thermal oxide film 450 and the silicon nitride film 200 are formed on the silicon substrate 400. Thereafter, the region where the supply port is formed may be removed by etching.

  In this case, the manufacturing method described in the above-described prior art can be manufactured by using the same mask only in the order of manufacturing steps without increasing the number of steps.

  After forming the Ta film 100 as shown in FIG. 3A (same as FIG. 2A), the protective resist 500 is formed on the surface of the silicon substrate 400 where the flow path is formed (the surface on which the Ta film 100 is formed). And a back resist is applied to the surface where the supply port etching is started.

  Next, the backside resist at the portion where the supply port is formed is removed using a normal photolithography method to form a backside resist pattern 600 (see FIG. 3B).

  Thereafter, the silicon substrate 400 is etched using the back resist pattern 600 as a mask to form the supply port 700. Etching is preferably performed using a Bosch process which is a kind of deep RIE (reactive ion etching) until the Ta film 100 as an etching stop layer is exposed (see FIG. 3C).

  Next, a state in which the Ta film 100 exposed to the supply port 700 is removed using the RIE method with the back surface resist pattern 600 as a mask is shown (see FIG. 3D).

  Next, the protective resist 500 and the back surface resist pattern 600 are peeled and removed (see FIG. 3 (5)). A general resist stripping solution may be used for stripping.

  After penetrating the supply port, the nozzle plate 800 is bonded to form an ink jet recording head (see FIG. 3 (6)). Here, an example is shown in which a polyimide film is processed with a laser and bonded together with an adhesive, but a flow path mold material can also be used.

  On the other hand, when a deep hole is formed using the RIE method, the supply amount of the etchant in the vicinity of the side wall of the hole may be reduced with respect to the central part of the hole. In this case, the central portion of the pattern may have a higher etching rate than the outer peripheral portion, and when etching is performed until the etching stop layer near the side wall of the opening is exposed, the etching stop layer is formed in the central portion of the opening. A portion from which the Ta film is removed may occur.

  The second embodiment is intended to provide a structure in which the above-described problems do not occur. This will be described in detail below with reference to FIGS.

  A thermal oxide film 450 is formed in a region where a heater is formed on the silicon substrate 400, and the heater 300 is formed on the thermal oxide film 450. A silicon nitride film 200 is formed so as to cover the heater 300. The region of the silicon nitride film 200 excluding the region where the future supply port is to be formed is removed, and the Ta film 100 is formed on the entire surface of the silicon (see FIGS. 4A and 4B).

  This forms a silicon nitride film (not shown) on the silicon substrate 400, then removes the silicon nitride film in a region where a future supply port will be formed, and exposes the silicon substrate in a region where a heater will be formed in the future. Next, the exposed silicon substrate is oxidized using a thermal oxidation method to form a thermal oxide film 450. Next, after forming the heater 300 on the thermal oxide film, the silicon nitride film 200 is formed. Thereafter, the region of the silicon nitride film 200 except for the central portion where the future supply port is to be formed is removed using a normal photolithography method and a dry etching method. Thereafter, a Ta film 100 is formed.

  In the present embodiment, similarly to the first embodiment, a structure is shown in which a thermal oxide film 450 is provided in a region where the heater 300 will be formed in the future. However, a thermal oxide film is formed on the silicon substrate 400. 450. After forming the silicon nitride film 200, the region where the supply port is formed can be removed by etching.

  FIG. 5 is a schematic process cross-sectional view using the aa cross section of FIG.

  After forming the Ta film 100 as shown in FIG. 5A (same as FIG. 4A), a protective resist 500 is applied to the surface where the flow path is formed, and the back surface resist is applied to the surface where the supply port etching is started. Apply.

  Next, the backside resist at the portion where the supply port is formed is removed to form a backside resist pattern 600 (see FIG. 5B). Thereafter, silicon etching is performed using a Bosch process using the backside resist pattern 600 as a mask to form a supply port 700. The central portion of the supply port 700 has a higher etching rate than the vicinity of the side wall of the supply port. Therefore, when the silicon nitride film 200 serving as an etching stop layer is exposed at the center of the supply port 700, the silicon substrate 400 remains in the vicinity of the side wall of the supply port 700 (see FIG. 5 (3)). .

  Thereafter, further etching is performed in the vicinity of the sidewall of the supply port 700 until the Ta film serving as an etching stop layer is exposed, thereby forming a supply port that penetrates the silicon substrate 400. When the etching stop layer is exposed in the vicinity of the side wall of the supply port 700, the silicon nitride film 200 and the Ta film 100 serving as the stopper layer are etched in the central portion of the supply port 700, but the protective resist 500 is exposed. (See Fig. 5 (4)).

  Next, a state where the Ta film 100 and the silicon nitride film 200 exposed to the supply port 700 are removed by using the RIE method is shown (see FIG. 5 (5)).

  Next, the protective resist 500 and the back surface resist pattern 600 are peeled and removed (see FIG. 5 (6)). A general resist stripping solution was used for stripping.

  After penetrating the supply port, the nozzle plate 800 is bonded to form an ink jet recording head (see FIG. 5 (7)). Here, an example is shown in which a polyimide film is processed with a laser and bonded together with an adhesive, but a flow path mold material can also be used.

  On the other hand, Ta generally has a large stress, and depending on the film forming conditions, a phenomenon such as peeling may occur in the state after the supply port etching.

  The third embodiment is intended to provide a structure that does not cause the above-described problems.

  In order to prevent the above problem from occurring, a part of the Ta film 100 at the center of the silicon nitride film 200 left at the center of the supply port shown in FIG. 4 is removed to disperse the stress of the Ta film 100. Thus, a phenomenon such as peeling of the Ta film 100 can be prevented.

  This will be described in detail below with reference to FIGS.

  A thermal oxide film 450 is formed in a region on the silicon substrate 400 where the heater is formed, and the heater 300 is formed on the thermal oxide film 450. A silicon nitride film 200 is formed so as to cover the heater 300. The region of the silicon nitride film 200 except for the central portion of the region where a future supply port is to be formed is removed. The Ta film 100 formed on the silicon nitride film 200 left in the region serving as the central portion of the supply port 700 is removed (see FIGS. 6A and 6B).

  This forms a silicon nitride film (not shown) on the silicon substrate 400, then removes the silicon nitride film in a region where a future supply port will be formed, and exposes the silicon substrate in a region where a heater will be formed in the future. Next, the exposed silicon substrate is oxidized using a thermal oxidation method to form a thermal oxide film 450. Next, after forming the heater 300 on the thermal oxide film, the silicon nitride film 200 is formed. Thereafter, the region of the silicon nitride film 200 except for the central portion where the future supply port is to be formed is removed using a normal photolithography method and a dry etching method. Thereafter, a Ta film 100 is formed.

  Thereafter, a Ta film 100 is formed, and the Ta film 100 formed on the silicon nitride film 200 left in the region serving as the central portion of the supply port 700 is removed using a normal photolithography method and a dry etching method. .

  In the present embodiment, similarly to the first embodiment, a structure is shown in which a thermal oxide film 450 is provided in a region where the heater 300 will be formed in the future. However, a thermal oxide film is formed on the silicon substrate 400. 450. After forming the silicon nitride film 200, the region where the supply port is formed can be removed by etching.

  FIG. 7 is a schematic process cross-sectional view using the aa cross section of FIG.

  The Ta film 100 is formed as shown in FIG. 7A (same as FIG. 6A), and the Ta film 100 formed on the silicon nitride film 200 left in the region to be the central portion of the supply port 700 is removed. After that, the protective resist 500 is applied to the surface where the flow path is formed, and the back surface resist is applied to the surface where the supply port etching is started.

  Next, the backside resist at the portion where the supply port is formed is removed to form a backside resist pattern 600 (see FIG. 7B). Thereafter, silicon etching is performed using a Bosch process with the backside resist pattern 600 as a mask, and etching is performed until the Ta film serving as an etching stop layer is exposed (see FIG. 7C).

  Next, a state where the Ta film 100 and the silicon nitride film 200 exposed to the supply port 700 are removed by using the RIE method is shown (see FIG. 7D).

  Next, the protective resist 500 and the back surface resist pattern 600 are peeled and removed (see FIG. 7 (5)). A general resist stripping solution can be used for stripping.

  After the supply port penetrating the silicon substrate 400 is formed, the nozzle plate 800 is bonded to form an ink jet recording head (see FIG. 7 (6)). Here, an example is shown in which a polyimide film is processed with a laser and bonded together with an adhesive, but a flow path mold material can also be used.

  An example in which a filter is formed in the supply port will be described with reference to FIGS. 8 and 9 as a fourth embodiment of the present invention.

  A thermal oxide film 450 is formed in a region on the silicon substrate 400 where the heater is formed, and the heater 300 is formed on the thermal oxide film 450. A silicon nitride film 200 is formed so as to cover the heater 300, a region where a future supply port of the silicon nitride film 200 is formed is removed, and a Ta film 100 is formed on the silicon substrate 400. Further, a filter layer 900 is provided at a position facing the region where the supply port 700 of the Ta film 100 is formed (see FIGS. 8A and 8B).

  This forms a silicon nitride film (not shown) on the silicon substrate 400, then removes the silicon nitride film in a region where a future supply port will be formed, and exposes the silicon substrate in a region where a heater will be formed in the future. Next, the exposed silicon substrate is oxidized using a thermal oxidation method to form a thermal oxide film 450. Next, after forming the heater 300 on the thermal oxide film, the silicon nitride film 200 is formed. Thereafter, the region of the silicon nitride film 200 except for the central portion where the future supply port is to be formed is removed using a normal photolithography method and a dry etching method. Thereafter, a Ta film 100 is formed. Next, the filter layer 900 is formed at a position facing the region where the supply port 700 of the Ta film 100 is formed.

  Also in the present embodiment, a structure in which the thermal oxide film 450 is provided in a region where the heater 300 will be formed in the future is shown. However, after the thermal oxide film 450 and the silicon nitride film 200 are formed on the silicon substrate 400, FIG. The region where the supply port is formed can be removed by etching.

  FIG. 9 is a schematic process cross-sectional view using the aa cross section of FIG.

  After forming the Ta film 100 as shown in FIG. 9A (same as FIG. 8A) and then providing the filter layer 900 at a position facing the region where the supply port 700 of the Ta film 100 is formed. The protective resist 500 is applied to the surface where the flow path is formed, and the back surface resist is applied to the surface where the supply port etching is started.

  Next, the backside resist at the portion where the supply port is formed is removed to form a backside resist pattern 600 (see FIG. 9B). Thereafter, silicon etching is performed using a Bosch process until the Ta film 100 as an etching stop layer is exposed using the backside resist pattern 600 as a mask to form a supply port 700 (see FIG. 9 (3)).

  Next, a state where the Ta film 100 exposed to the supply port 700 is removed by using the RIE method is shown (see FIG. 9 (4)).

  Next, the protective resist 500 and the back surface resist pattern 600 are peeled and removed (see FIG. 9 (5)). A general resist stripping solution can be used for stripping.

  After penetrating the supply port, the nozzle plate 800 is bonded to form an ink jet recording head (see FIG. 9 (6)). Here, an example is shown in which a polyimide film is processed with a laser and bonded together with an adhesive, but a flow path mold material can also be used.

  As a fifth embodiment of the present invention, a manufacturing method using a flow path mold will be described with reference to a schematic process cross-sectional view using the aa cross-section of FIG. 2B.

  A thermal oxide film 450 is formed in a region on the silicon substrate 400 where the heater is formed, and the heater 300 is formed on the thermal oxide film 450. A silicon nitride film 200 is formed so as to cover the heater 300. The region of the silicon nitride film 200 excluding the region where the future supply port is to be formed is removed, and the Ta film 100 is formed on the entire surface of the silicon (see FIG. 10A).

  This forms a silicon nitride film (not shown) on the silicon substrate 400, then removes the silicon nitride film in a region where a future supply port will be formed, and exposes the silicon substrate in a region where a heater will be formed in the future. Next, the exposed silicon substrate is oxidized using a thermal oxidation method to form a thermal oxide film 450. Next, after forming the heater 300 on the thermal oxide film, the silicon nitride film 200 is formed. Thereafter, the region of the silicon nitride film 200 except for the central portion where the future supply port is to be formed is removed using a normal photolithography method and a dry etching method. Thereafter, a Ta film 100 is formed.

  Thereafter, the flow path mold member 870 is formed using a soluble resin, and then the nozzle member 850 serving as a flow path wall is formed so as to cover the flow path mold member 870. A liquid discharge port 880 is formed at a position facing the heater 300 of the nozzle material 850. Thereafter, a protective resist 500 is applied on the nozzle material 850, and a backside resist is formed on the surface of the supply port where etching is started.

  Next, the backside resist at the portion where the supply port is formed is removed to form a backside resist pattern 600 (see FIG. 10B).

  Thereafter, silicon etching is performed using a Bosch process until the Ta film 100 as an etching stop layer is exposed using the backside resist pattern 600 as a mask to form a supply port 700 (see FIG. 10 (3)).

  Next, a state in which the Ta film 100 exposed to the supply port 700 is removed by using the RIE method is shown (see FIG. 10 (4)).

  Next, the protective resist 500 and the back surface resist pattern 600 are peeled and removed (see FIG. 10 (5)). A general resist stripping solution was used for stripping.

  Thereafter, the liquid discharge recording head is formed by dissolving and removing with a solvent through the liquid discharge port 880 and the supply port 700 (see FIG. 10 (6)).

  Hereinafter, although the liquid discharge recording head based on this invention is demonstrated based on an Example, this invention is not limited by this.

(Example)
Example 1
The present example is an example corresponding to the first embodiment. The details of the present embodiment will be described below based on the schematic process cross-sectional view of FIG.

  A silicon nitride film was formed on a silicon substrate 400 having a thickness of 200 μm, and after removing the silicon nitride film in a region where a thermal oxide film was to be formed, a thermal oxide film 450 having a thickness of 500 nm was formed. After removing the silicon nitride film, a heater 300 and a silicon nitride film 200 serving as a first protective film for obtaining insulation of wiring (not shown) were formed on the thermal oxide film 450. Thereafter, the silicon nitride film 200 in the region where the supply port is formed is removed using an etching method such as a dry etching method to form a Ta film 100 serving as a second protective film having mechanical strength (FIG. 3 ( 1)).

  The silicon nitride film 200 is formed using a CVD method, the film thickness is 300 nm, and the Ta film 100 is formed by a sputtering method, and the film thickness is 230 nm.

  Next, a protective resist 500 was applied to the side where the flow path of the silicon substrate 400 was formed, and a backside resist was formed on the side where supply port etching was started. Thereafter, the backside resist in the region where the supply port is formed was removed to form a backside resist pattern 600 (see FIG. 3B).

  In this embodiment, a resist is used, but a material such as a dry film can also be used. In this example, the protective resist 500 and the back resist were formed of OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd. using a coating method so as to have a film thickness of 7 μm.

  Next, the silicon substrate 400 was etched by deep RIE using the back resist pattern 600 as a mask. The silicon substrate 400 was etched until the Ta film 100 serving as an etching stop layer was exposed to the supply port 700, and the supply port 700 penetrating the silicon substrate 400 was formed (see FIG. 3 (3)).

  In this embodiment, the Bosch process is used. However, the Bosch process is not necessarily limited, and a deep RIE method other than the Bosch process may be used.

  The conditions of the Bosch process are not particularly limited, but in this embodiment, the plasma power is 2000 W and the substrate bias is 100 W. The substrate bias was controlled by pulses and repeated 20 ms (ON) and 80 ms (OFF).

The supply gas was SF ₆ for the purpose of etching and C ₄ F ₈ for the purpose of protecting the side walls. SF ₆ and C ₄ F ₈ were alternately flowed for 3 seconds and 1 second, respectively. The flow rates at that time were 300 sccm and 150 sccm, respectively, and the pressure was set to 4.8 Pa. The substrate temperature was controlled to 20 ° C. with a refrigerant.

  When the etching progresses and the supply port 700 penetrates the silicon substrate 400, the Ta film 100 serving as an etching stop layer is exposed to the supply port 700. Since the Ta film 100 is a metal film, the etching stop layer is not positively charged, so that a notch is hardly generated.

Next, the Ta film 100 as an etching stop layer was removed by dry etching using a gas such as CF ₄ (see FIG. 3 (4)).

  Then, it removed using the protective resist 500, the back surface resist pattern 600, and resist stripping solution (refer FIG. 3 (5)). As the remover, a remover for OFPR800 can be used.

  Next, the nozzle plate 800 was bonded to complete the liquid discharge head (see FIG. 3 (6)). As a material for the nozzle plate 800, for example, a polyimide film was used. The polyimide film was processed with a laser to form the nozzle plate 800, and then bonded using an adhesive.

  In the present embodiment, the process of attaching the nozzle plate to the substrate after forming the supply port is shown. However, as shown in Example 5 described later, the manufacturing method for providing the flow path pattern shown in the prior art can be applied.

(Example 2)
This example is an example corresponding to the second embodiment. Hereinafter, the details of the present embodiment will be described based on the schematic process cross-sectional view of FIG.

  A silicon nitride film was formed on a silicon substrate 400 having a thickness of 200 μm, and after removing the silicon nitride film in a region where a thermal oxide film was to be formed, a thermal oxide film 450 having a thickness of 500 nm was formed. Thereafter, the silicon nitride film was removed. Next, a 300-nm-thick silicon nitride film 200 serving as a first protective film for obtaining insulation between the heater 300 and wiring (not shown) was formed on the thermal oxide film 450 by using the CVD method. .

  Thereafter, the silicon nitride film 200 at the end of the region where the supply port is to be formed in the future was removed using a photolithography method and a dry etching method.

  Next, a Ta film 100 having a thickness of 230 nm was formed by sputtering (see FIG. 5A).

  Next, a protective resist 500 was applied to the side where the flow path of the silicon substrate 400 was formed, and a backside resist was formed on the side where supply port etching was started. Thereafter, the back surface resist in the region where the supply port is formed was removed to form a back surface resist pattern 600 (see FIG. 5B).

  Note that OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd. was used for the protective resist 500 and the backside resist, and the film thickness was 7 μm by a coating method.

  In this embodiment, a resist is used, but a material such as a dry film can also be used.

  Next, a supply port 700 penetrating the silicon substrate 400 is formed by deep RIE using the back resist pattern 600 as a mask. At this time, when a deep opening is formed like the supply port 700, the amount of the etchant supplied in the vicinity of the side wall of the supply port 700 may be smaller than the central portion of the supply port 700. When such a state occurs, the etching rate near the wall surface may be slower than the etching rate at the center. As a result, the etching stop layer is exposed at the central portion of the supply port 700, but etching may not be completed on the wall surface side of the supply port 700 (see FIG. 5 (3)).

  In this case, since the etching rate of the supply port 700 in the central part of the supply port is high, when the etching on the wall surface side of the supply port 700 is finished (the supply port penetrates the silicon substrate), the etching further proceeds in the central part. As a result, the etching stop layer is etched at the center of the supply port 700 (see FIG. 5 (4)). However, in this embodiment, the central portion of the supply port 700 has a two-layer structure in which the Ta film 100 is formed on the silicon nitride film 200. For this reason, the possibility that the etching stop layer in the central portion is eliminated is reduced.

  In this embodiment, an etching stop layer made of an insulating film is exposed at the central portion of the supply port. However, since the silicon substrate or Ta film is exposed in the vicinity of the wall surface of the supply port until the etching is completed, charging is not performed. Does not occur.

  As the deep RIE method, the Bosch process was also used in this example.

  The conditions of the Bosch process are not particularly limited, but in this embodiment, the plasma power is 2000 W and the substrate bias is 100 W. The substrate bias was controlled by pulses and repeated 20 ms (ON) and 80 ms (OFF).

The supply gas was SF ₆ for the purpose of etching and C ₄ F ₈ for the purpose of protecting the side walls. SF ₆ and C ₄ F ₈ were alternately flowed for 3 seconds and 1 second, respectively. The flow rates at that time were 300 sccm and 150 sccm, respectively, and the pressure was set to 4.8 Pa. The substrate temperature was controlled to 20 ° C. with a refrigerant.

Next, the Ta film 100 and the silicon nitride film 200, which are etching stop layers, were removed by dry etching using a gas such as CF ₄ (see FIG. 5 (5)).

  Then, it removed using the protective resist 500, the back surface resist pattern 600, and resist stripping solution (refer FIG. 5 (6)). As the remover, a remover for OFPR800 can be used.

  Next, the nozzle plate 800 was bonded to complete the liquid discharge head (see FIG. 5 (7)). As a material for the nozzle plate 800, for example, a polyimide film was used. The polyimide film was processed with a laser to form a nozzle plate 800, and then bonded using an adhesive.

  In the present embodiment, the process of attaching the nozzle plate to the substrate after forming the supply port is shown. However, as shown in Example 5 described later, the manufacturing method for providing the flow path pattern shown in the prior art can be applied.

(Example 3)
Ta generally has a large stress, and depending on the film formation conditions, a phenomenon such as peeling may occur in the state after etching of the supply port.

  In order to prevent the above-described problem from occurring, a part of the Ta film 100 on the silicon nitride film 200 left in the central portion of the supply port in Example 2 is removed, and the stress of the Ta film 100 is dispersed. Phenomena such as peeling of the Ta film 100 can be prevented.

  Hereafter, the manufacturing method of a present Example is demonstrated in detail using the typical process sectional drawing of FIG.

    A silicon nitride film was formed on a silicon substrate 400 having a thickness of 200 μm, and after removing the silicon nitride film in a region where a thermal oxide film was to be formed, a thermal oxide film 450 having a thickness of 500 nm was formed. Thereafter, the silicon nitride film was removed. Next, a 300-nm-thick silicon nitride film 200 serving as a first protective film for obtaining insulation between the heater 300 and wiring (not shown) was formed on the thermal oxide film 450 by using the CVD method. .

  Thereafter, the silicon nitride film 200 at the end of the region where the supply port is to be formed in the future was removed using a photolithography method and a dry etching method.

  Next, after forming the Ta film 100 having a film thickness of 230 nm by sputtering, the Ta film 100 on the silicon nitride film 200 provided in the region where the supply port is formed is subjected to photolithography and dry etching. (See FIG. 7 (1)).

  Next, a protective resist 500 was applied to the side where the flow path of the silicon substrate 400 was formed, and a backside resist was formed on the side where supply port etching was started. Thereafter, the back surface resist in the region where the supply port is formed was removed to form a back surface resist pattern 600 (see FIG. 7B).

  Note that OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd. was used for the protective resist 500 and the backside resist, and the film thickness was 7 μm by a coating method.

  In this embodiment, a resist is used, but a material such as a dry film can also be used.

  Next, the silicon substrate 400 was subjected to deep RIE using the back resist pattern 600 as a mask. Etching of the silicon substrate 400 was performed until the Ta film 100 and the silicon nitride film 200 serving as an etching stop layer were exposed to the supply port 700, thereby forming the supply port 700 penetrating the silicon substrate 400 (see FIG. 7 (3)). .

  Even if the silicon substrate under the etching stop layer is etched and the balance of the film stress of the Ta film 100 serving as the etching stop layer changes, the Ta film 100 in the center of the supply port is removed, The phenomenon is unlikely to occur.

  As the deep RIE method, the Bosch process was also used in this example.

  The conditions of the Bosch process are not particularly limited, but in this embodiment, the plasma power is 2000 W and the substrate bias is 100 W. The substrate bias was controlled by pulses and repeated 20 ms (ON) and 80 ms (OFF).

The supply gas was SF ₆ for the purpose of etching and C ₄ F ₈ for the purpose of protecting the side walls. SF ₆ and C ₄ F ₈ were alternately flowed for 3 seconds and 1 second, respectively. The flow rates at that time were 300 sccm and 150 sccm, respectively, and the pressure was set to 4.8 Pa. The substrate temperature was controlled to 20 ° C. with a refrigerant.

Next, the Ta film 100 and the silicon nitride film 200, which are etching stop layers, were removed by dry etching using a gas such as CF ₄ (see FIG. 7 (4)).

  Then, it removed using the protective resist 500, the back surface resist pattern 600, and resist stripping solution (refer FIG. 7 (5)). As the remover, a remover for OFPR800 can be used.

  Next, the nozzle plate 800 was bonded to complete the liquid discharge head (see FIG. 7 (6)). As a material for the nozzle plate 800, for example, a polyimide film was used. The polyimide film was processed with a laser to form the nozzle plate 800, and then bonded using an adhesive.

  In the present embodiment, the process of attaching the nozzle plate to the substrate after forming the supply port is shown. However, as shown in Example 5 described later, the manufacturing method for providing the flow path pattern shown in the prior art can be applied.

Example 4
In this embodiment, a filter is formed in the supply port, and the manufacturing method will be described with reference to the schematic process cross-sectional view of FIG.

  A silicon nitride film was formed on a silicon substrate 400 having a thickness of 200 μm, and after removing the silicon nitride film in a region where a thermal oxide film was to be formed, a thermal oxide film 450 having a thickness of 500 nm was formed. Next, the silicon nitride film was removed. Next, a heater 300 and a silicon nitride film 200 serving as a first protective film for obtaining insulating properties of wiring (not shown) were formed on the thermal oxide film 450. Thereafter, the silicon nitride film 200 in the region where the supply port is to be formed is removed by using an etching method such as a dry etching method to form a Ta film 100 serving as a second protective film having mechanical strength.

  Thereafter, a filter layer 900 was formed at a position facing a region where a future supply port of the silicon substrate 400 of the Ta film 100 was formed (see FIG. 9A).

  The silicon nitride film 200 is formed using a CVD method, the film thickness is 300 nm, and the Ta film 100 is formed by a sputtering method, and the film thickness is 230 nm.

  As a material of the filter layer 900, an inorganic film, an organic film, or the like can be used. When the supply port is formed after the filter is formed, the etching stop layer serves as a protective layer for the filter.

  Next, a protective resist 500 was applied to the side where the flow path of the silicon substrate 400 was formed, and a backside resist was formed on the side where supply port etching was started. Thereafter, the back resist in the region where the supply port is formed was removed, and a back resist pattern 600 was formed (see FIG. 9B).

  In this embodiment, a resist is used, but a material such as a dry film can also be used. In this example, the protective resist 500 and the back resist were formed of OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd. using a coating method so as to have a film thickness of 7 μm.

  Next, the silicon substrate 400 was subjected to deep RIE using the back resist pattern 600 as a mask. Etching of the silicon substrate 400 was performed until the Ta film 100 serving as an etching stop layer was exposed to the supply port 700, and the supply port 700 penetrating the silicon substrate 400 was formed (see FIG. 9 (3)).

  In this embodiment, the Bosch process is used. However, the Bosch process is not necessarily limited, and a deep RIE method other than the Bosch process may be used.

  The conditions of the Bosch process are not particularly limited, but in this embodiment, the plasma power is 2000 W and the substrate bias is 100 W. The substrate bias was controlled by pulses and repeated 20 ms (ON) and 80 ms (OFF).

The supply gas was SF ₆ for the purpose of etching and C ₄ F ₈ for the purpose of protecting the side walls. SF ₆ and C ₄ F ₈ were alternately flowed for 3 seconds and 1 second, respectively. The flow rates at that time were 300 sccm and 150 sccm, respectively, and the pressure was set to 4.8 Pa. The substrate temperature was controlled to 20 ° C. with a refrigerant.

  When the etching progresses and the supply port 700 penetrates the silicon substrate 400, the Ta film 100 serving as an etching stop layer is exposed to the supply port 700. Since the Ta film 100 is a metal film, the etching stop layer is not positively charged, so that a notch is hardly generated.

Next, the Ta film 100 which is an etching stop layer was removed by dry etching using a gas such as CF ₄ (see FIG. 9 (4)).

The Ta film 100 can be anisotropically dry etched mainly using radicals using a gas such as CF ₄ . In this case, for example, when the material of the filter layer 900 is resin, the etching selectivity between the filter layer 900 and the Ta film 100 serving as an etching stop layer can be increased, so that damage to the filter layer 900 is reduced.

  Thereafter, the protective resist 500 and the back surface resist pattern 600 were removed using a resist stripping solution (see FIG. 9 (5)). As the remover, a remover for OFPR800 can be used.

  Next, the nozzle plate 800 was bonded to complete the liquid discharge head (see FIG. 9 (6)). As a material for the nozzle plate 800, for example, a polyimide film was used. The polyimide film was processed with a laser to form the nozzle plate 800, and then bonded using an adhesive.

  In the present embodiment, the process of attaching the nozzle plate to the substrate after forming the supply port is shown. However, as shown in Example 5 described later, the manufacturing method for providing the flow path pattern shown in the prior art can be applied.

(Example 5)
In FIG. 10, the nozzle plate of Example 1 is
(1) forming an ink flow path pattern with a soluble resin;
(2) A coating resin containing an epoxy resin that is solid at room temperature is dissolved in a solvent, and this is solvent-coated on a soluble resin layer, thereby forming a coating that becomes an ink flow path wall on the soluble resin layer. Forming a resin layer;
(3) forming an ink discharge port in the coating resin layer above the ink discharge pressure generating element;
(4) The process for eluting the soluble resin layer is described in detail with reference to the schematic cross-sectional process diagram of FIG.

  A silicon nitride film was formed on a silicon substrate 400 having a thickness of 200 μm, and after removing the silicon nitride film in a region where a thermal oxide film was to be formed, a thermal oxide film 450 having a thickness of 500 nm was formed. Next, the silicon nitride film was removed. Next, a heater 300 and a silicon nitride film 200 serving as a first protective film for obtaining insulating properties of wiring (not shown) were formed on the thermal oxide film 450. Thereafter, the silicon nitride film 200 in the region where the supply port is formed is removed using an etching method such as a dry etching method to form a Ta film 100 serving as a second protective film having mechanical strength (FIG. 10 ( 1)).

  The silicon nitride film 200 is formed using a CVD method, the film thickness is 300 nm, and the Ta film 100 is formed by a sputtering method, and the film thickness is 230 nm.

  Thereafter, the flow path mold member 870 was formed using a soluble resin, and then the nozzle member 850 serving as a flow path wall was formed so as to cover the flow path mold member 870. A novolac positive resist was used as the soluble resin, and a negative resist was used for the nozzle material 850.

  For the flow path mold 870, a novolac positive resist was applied on the silicon substrate 400, and then a pattern was formed using a normal photolithography method. Similarly, after applying a negative resist to the nozzle substrate 850 on the silicon substrate, pattern formation was performed using a normal photolithography method. At the same time, the liquid discharge port 880 was formed at a position facing the heater 300.

  Then, the protective resist 500 was apply | coated on the nozzle material 850, and the back surface resist was formed in the surface where the etching of a supply port is started.

  Next, the backside resist at the portion where the supply port was formed was removed to form a backside resist pattern 600 (see FIG. 10 (2)).

  In this embodiment, a resist is used, but a material such as a dry film can also be used. In this example, the protective resist 500 and the back resist were formed of OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd. using a coating method so as to have a film thickness of 7 μm.

  In this embodiment, the liquid discharge port 880 is formed on the negative resist by using the photolithography method, but a resist pattern is formed on the nozzle material 850, and this can be used as a mask by dry etching or the like. .

  Thereafter, silicon etching is performed using a Bosch process until the Ta film 100 as an etching stop layer is exposed using the backside resist pattern 600 as a mask to form a supply port 700 (see FIG. 10 (3)).

  Next, a state in which the Ta film 100 exposed to the supply port 700 is removed by using the RIE method is shown (see FIG. 10 (4)).

  Next, the protective resist 500 and the back surface resist pattern 600 are peeled and removed (see FIG. 10 (5)). A general resist stripping solution was used for stripping.

  After passing through the supply port, the flow path mold member 870 was dissolved and removed by the stripping solution through the liquid discharge port 880 and the supply port 700, thereby forming a liquid discharge recording head (see FIG. 10 (6)). Here, a normal resist stripping solution was used as the stripping solution.

(Comparative example)
As a comparative example, an example in which a silicon-based insulating film is used as an etching stop layer will be described with reference to a schematic process sectional view of FIG.

  A thermal oxide film 450 having a thickness of 500 nm was formed on a silicon substrate 400 having a thickness of 200 μm. Next, a heater 300 and a silicon nitride film 200 and a Ta film 100 serving as a first protective film for obtaining insulation of wiring (not shown) were formed on the thermal oxide film 450. Thereafter, the Ta film 100 and the silicon nitride film 200 corresponding to a region where a supply port is to be formed in the future were removed by using a normal photolithography method and a dry etching method (see FIG. 13A).

  The silicon nitride film 200 is formed using a CVD method, the film thickness is 300 nm, and the Ta film 100 is formed by a sputtering method, and the film thickness is 230 nm.

  A protective resist 500 is applied to the surface where the flow path is to be formed, and a back surface resist is formed on the surface where the supply port etching is started.

  Next, a protective resist 500 was applied to the side where the flow path of the silicon substrate 400 was formed, and a backside resist was formed on the side where supply port etching was started. Thereafter, the backside resist in the region where the supply port is formed was removed, and a backside resist pattern 600 was formed (see FIG. 13B).

  In this comparative example, the protective resist 500 and the back resist were formed by using an OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd. by a coating method so that the film thickness was 7 μm.

  Next, the supply port 700 was formed by deep digging the silicon substrate 400 using the back resist pattern 600 as a mask. The silicon substrate 400 was etched until the thermal oxide film 450 serving as an etching stop layer was exposed to the supply port 700, thereby forming the supply port 700 penetrating the silicon substrate 400 (see FIG. 13 (3)).

  In this comparative example, the Bosch process is used, but it is not necessary to limit to the Bosch process. Of course, a deep RIE method other than the Bosch process may be used.

  The conditions of the Bosch process are not particularly limited, but in this comparative example, the plasma power was 2000 W and the substrate bias was 100 W. The substrate bias was controlled by pulses and repeated 20 ms (ON) and 80 ms (OFF).

The supply gas was SF ₆ for the purpose of etching and C ₄ F ₈ for the purpose of protecting the side walls. SF ₆ and C ₄ F ₈ were alternately flowed for 3 seconds and 1 second, respectively. The flow rates at that time were 300 sccm and 150 sccm, respectively, and the pressure was set to 4.8 Pa. The substrate temperature was controlled to 20 ° C. with a refrigerant.

  Next, the thermal oxide film 450 exposed at the supply port 700 was removed by RIE (see FIG. 13 (4)).

  Next, the protective resist 500 and the back surface resist pattern 600 were peeled and removed (see FIG. 13 (5)). A general resist stripping solution was used for stripping.

  After penetrating the supply port, the nozzle plate 800 was bonded to form an ink jet recording head (see FIG. 13 (6)).

  In this comparative example, as shown in FIG. 13 (3), when the supply port 700 is formed using the thermal oxide film 450 as an etching stop layer, the thermal oxide film of the silicon substrate 400 is affected by the effect of charging of the thermal oxide film 450. In some cases, a notch was formed at the interface.

  When the liquid discharge recording heads of Example 1-5 and the comparative example were assembled and printing was performed, the distance between the heater and the supply port was assumed to be smaller than the set value in the portion where the notch occurred. Discharge performance could not be obtained.

FIG. 3 is a perspective view for explaining the structure of a substrate for an ink jet recording head of Example 1. FIG. 3 is a schematic diagram for explaining a structure of an ink jet recording head substrate of Example 1. FIG. FIG. 3 is a schematic process cross-sectional view for explaining a process of the first embodiment. FIG. 6 is a schematic diagram for explaining the structure of a substrate for an ink jet recording head of Example 2. FIG. 6 is a schematic process cross-sectional view for explaining a process of Example 2. FIG. 5 is a schematic diagram for explaining the structure of an ink jet recording head substrate of Example 3. FIG. 10 is a schematic process cross-sectional view for explaining a process of the third embodiment. 6 is a schematic diagram for explaining the structure of a substrate for an ink jet recording head of Example 4. FIG. FIG. 10 is a schematic process cross-sectional view for explaining a process of the fourth embodiment. FIG. 10 is a schematic process cross-sectional view for explaining a process of the fifth embodiment. FIG. 5 is a schematic diagram for explaining the structure of a base for an inkjet recording head of a comparative example. It is a schematic diagram for demonstrating a comparative example. Typical process sectional drawing for demonstrating the process of a comparative example.

Explanation of symbols

100 Ta (tantalum) film 200 Silicon nitride 300 Heater 400 Silicon substrate 450 Thermal oxide film 500 Protective resist 600 Back side resist pattern 700 Supply port 770 Notch 800 Nozzle plate 850 Nozzle material 870 Channel type material 900 Filter layer

Claims (8)

A liquid discharge pressure generating element provided on a silicon-based insulating film provided on a silicon substrate, a flow path provided on the liquid discharge pressure generating element, and supplying a liquid to the flow path A manufacturing method of a liquid discharge recording head having a supply port penetrating a substrate,
Forming the silicon-based insulating film in a region for forming the liquid discharge pressure generating element;
Providing the liquid discharge pressure generating element on the silicon-based insulating film;
Forming a first protective film made of a silicon-based insulating film on the liquid discharge pressure generating element;
Removing the first protective film in a region to be an end portion of a region where at least a future supply port of the silicon substrate is formed;
Thereafter, a step of forming a second protective film made of a metal material,
Forming the supply port penetrating the silicon substrate using reactive ion etching;
Then, removing the first protective film that becomes the etching stop layer of the reactive ion etching exposed to the supply port, or the first protective film and the second protective film,
And a step of forming a nozzle plate having an ejection port for forming the flow path so as to cover the supply port.   2. The method of manufacturing a liquid discharge recording head according to claim 1, wherein an etching stop layer formed in a region where the supply port is formed is the second protective film. The etching stop layer formed in the region where the supply port is formed is the second protective film at the outer edge portion of the supply port, and the first protective film at the central portion of the supply port,
The method of manufacturing a liquid discharge recording head according to claim 1, wherein the second protective film is formed on the first protective film.   4. The method of manufacturing a liquid discharge recording head according to claim 3, further comprising a step of removing the second protective film at a central portion of the first protective film.   5. The method of manufacturing a liquid discharge recording head according to claim 1, further comprising a step of providing a filter layer on the second protective film after forming the second protective film.   The method of manufacturing a liquid discharge recording head according to claim 1, wherein the metal material is Ta.   The method of manufacturing a liquid discharge recording head according to claim 2, wherein the first protective film is a silicon-based insulating film. Forming the nozzle plate comprises:
(1) forming an ink flow path pattern with a soluble resin;
(2) A coating resin containing an epoxy resin that is solid at room temperature is dissolved in a solvent, and this is solvent-coated on the soluble resin layer, whereby the nozzle plate and the nozzle plate are formed on the soluble resin layer. Forming a coating resin layer comprising:
(3) forming an ink discharge port in the coating resin layer above the liquid discharge pressure generating element;
(4) The method for manufacturing a liquid discharge recording head according to any one of claims 1 to 7, further comprising a step of eluting the soluble resin layer.

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