JP2007210176A - Method for processing silicon substrate and method for manufacturing liquid jet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for processing a silicon substrate capable of improving the dimensional accuracy of a slit, in particular, the dimensional accuracy of the length of a narrow width part when a channel part and the slit with the narrow width part with a width narrower than that of the channel part are formed on the silicon substrate. <P>SOLUTION: The method has a first etching process wherein a protective film 52 with a specified shape is formed on the silicon substrate 110, an anisotropic etching of the silicon substrate is performed by using this protective film as a mask, to form the slit so as to make the length of the narrow width part longer than a specified length, a mask processing process wherein a cutout part 52a is formed on the protective film in a region corresponding to a protruding part 16 provided by protruding more inside of the slit than the side face of the channel part and forming the narrow width part so that at least a part of the end face on the narrow width part side of the protruding part is exposed, and a second etching process wherein by performing the anisotropic etching of the silicon substrate by using the protective film with the cutout part as the mask, the narrow width part is made to be a specified length. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a silicon substrate processing method for forming a narrow groove having a narrow portion on a silicon substrate by wet etching, and a method for manufacturing a liquid jet head using the silicon substrate processing method.

  In the case where a narrow groove or the like is formed on a silicon substrate, for example, it is known that an anisotropic etching processing technique using a difference in etching rate with respect to an alkaline solution is used. For example, when a silicon substrate having a plane orientation (110) is anisotropically etched, a first (111) plane perpendicular to the (110) plane and a second (110) plane forming a predetermined angle with the first (111) plane. The etching rate of the (111) plane is very slow. For this reason, when a narrow groove is formed by anisotropically etching a silicon substrate having a plane orientation (110), the inner surface of the narrow groove is basically the first (111) plane and the second (111) plane. Formed with. For this reason, the narrow groove can be formed with extremely high accuracy by using the anisotropic etching technique.

  For example, a thin groove is formed in a silicon substrate by using anisotropic etching. For example, an ink flow path of an ink jet recording head is used as a flow path forming substrate made of a silicon single crystal substrate having a plane orientation (110). In some cases, it is formed by anisotropic etching (see, for example, Patent Document 1).

  Here, for example, in the structure described in Patent Document 1, a pressure generating chamber (groove portion) having a predetermined width is formed on a flow path forming substrate which is a silicon substrate, and an ink supply path (narrow portion) having a narrower width than the pressure generating chamber. An ink flow path (thin groove) is formed. These are simultaneously formed by anisotropically etching the flow path forming substrate.

  As described above, by using the anisotropic etching technique, the narrow groove can be formed in the silicon substrate with high accuracy. However, for example, as in Patent Document 1, if a pressure generation chamber and an ink supply path narrower than the pressure generation chamber are simultaneously formed on a silicon substrate having a plane orientation (110) by anisotropic etching, ink supply There are problems that the dimensional accuracy of the length of the road is low and that the dimensions are likely to vary. When the pressure generation chamber and the ink supply path are formed simultaneously as described above, a surface other than the first and second (111) surfaces is formed at the boundary between the pressure generation chamber and the ink supply path. When anisotropically etching a silicon single crystal substrate having a plane orientation (110), the etching rate of the surfaces other than the first and second (111) planes is relatively fast, so that the dimensional accuracy of the length of the ink supply path is high. There is a problem that it becomes low and the size is likely to vary.

JP 2005-014265 A

  In view of the circumstances described above, the present invention provides a dimensional accuracy of the narrow groove, particularly a dimensional accuracy of the length of the narrow portion, when forming a groove having a narrow portion narrower than the groove portion on the silicon substrate. It is an object to provide a silicon substrate processing method that can be improved. It is another object of the present invention to provide a method of manufacturing a liquid ejecting head that can improve ejection characteristics by improving the dimensional accuracy of an ink flow path that is a narrow groove.

A first aspect of the present invention that solves the above-described problems is a narrow groove having a groove portion having a predetermined width and a narrow portion having a predetermined length that is provided in a part of the groove portion in the longitudinal direction and is narrower than the groove portion. A method of processing a silicon substrate formed on a silicon substrate by anisotropic etching, wherein a protective film having a predetermined shape is formed on the silicon substrate, and the silicon substrate is anisotropically etched using the protective film as a mask. A first etching step of forming the narrow groove so that a length of the narrow portion is longer than the predetermined length; and the narrow portion provided to protrude from the side surface of the groove portion to the inside of the narrow groove. A mask processing step of forming a notch portion in the protective film in a region corresponding to the overhang forming portion so as to expose at least a part of the end surface on the narrow portion side of the overhang portion, and the notch portion. Have In the processing method of a silicon substrate and having a the narrow portion by anisotropically etching the silicon substrate as a mask protective film and the second etching step of the predetermined length that.
In the first aspect, the etching of the silicon substrate proceeds through the notch portion in the second etching step, so that the final overhanging is performed regardless of the length of the overhanging portion formed in the first etching step. The length of the part is determined. For this reason, for example, even when the length of the overhang portion varies in the first etching step, the final overhang portion can be formed with a uniform length. That is, according to the manufacturing method of the present invention, it is possible to greatly improve the dimensional accuracy of the narrow groove, particularly the dimensional accuracy of the length of the narrow portion.

According to a second aspect of the present invention, in the mask processing step, the notch portion is formed so that at least a part of an end surface of the protruding portion on the groove portion side is exposed. The method is for processing a silicon substrate.
In the second aspect, since the overhanging portion can be satisfactorily etched through the notch portion in the second etching step, the dimensional accuracy of the overhanging portion is more reliably improved.

A third aspect of the present invention is the silicon substrate processing method according to the first or second aspect, wherein, in the mask processing step, the notch is formed in the protective film by laser processing.
In the third aspect, the notch can be formed with high accuracy. Along with this, the dimensional accuracy of the overhanging portion is also improved more reliably.

According to a fourth aspect of the present invention, there is provided the silicon substrate processing method according to any one of the first to third aspects, wherein the protective film is made of silicon nitride (SiN).
In the fourth aspect, by forming the protective film with a predetermined material, the protective film can be formed in a predetermined pattern with high accuracy, and the notch can be formed well. Therefore, the dimensional accuracy of the overhanging portion is more reliably improved.

According to a fifth aspect of the present invention, there is provided the silicon substrate processing method according to any one of the first to fourth aspects, wherein the silicon substrate is formed of a silicon single crystal substrate having a (110) surface. .
In the fifth aspect, by using a silicon substrate having a predetermined plane orientation, the narrow groove can be formed with higher accuracy, and the dimensional accuracy of the overhanging portion is more reliably improved.

According to a sixth aspect of the present invention, in the method for processing a silicon substrate according to any one of the first to fifth aspects, the narrow groove is formed along a (111) plane perpendicular to the (110) plane. It is in.
In the sixth aspect, the narrow groove can be formed with higher accuracy, and the dimensional accuracy of the overhanging portion is more reliably improved.

According to a seventh aspect of the present invention, there is provided a flow path forming substrate having a flow path including a pressure generation chamber made of a silicon substrate and communicating with a nozzle and a supply path having a narrower width than the pressure generation chamber, and the pressure generation chamber And a pressure generating means for generating a pressure for ejecting liquid droplets on the flow path forming substrate as a step of forming the flow path on the flow path forming substrate. A flow path is formed so that the length of the supply path is longer than the predetermined length by forming a protective film of a predetermined shape and anisotropically etching the flow path forming substrate using the protective film as a mask. And at least the supply of the overhanging portion in the protective film in a region corresponding to the overhanging portion that is provided to protrude from the side surface of the pressure generating chamber to the inside of the flow path and forms the supply path. A mask processing step of forming a notch so that a part of the end face on the side is exposed, and anisotropically etching the flow path forming substrate using the protective film having the notch as a mask to And a second etching step having the predetermined length.
In the seventh aspect, the etching of the flow path forming substrate proceeds through the notch portion in the second etching step, so that the final shape is obtained regardless of the length of the overhang portion formed in the first etching step. The length of the overhanging part is determined. For this reason, for example, even when the length of the overhang portion varies in the first etching step, the final overhang portion can be formed with a uniform length. That is, according to the manufacturing method of the present invention, the dimensional accuracy of the flow channel, particularly the dimensional accuracy of the length of the supply channel can be greatly improved.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is an exploded perspective view showing an example of an ink jet recording head manufactured by the manufacturing method according to Embodiment 1, and FIG. 2 is a schematic plan view of FIG. FIG. 3 is a plan view of the flow path forming substrate. As shown in the figure, the flow path forming substrate 10 is composed of a silicon single crystal substrate having a plane orientation (110) in the present embodiment. The flow path forming substrate 10 includes a groove portion having a predetermined width and a longitudinal direction of the groove portion. An ink flow path including a narrow groove having a narrow portion with a predetermined length that is provided in the portion and narrower than the groove portion is formed. Specifically, the flow path forming substrate 10 is provided with pressure generating chambers 12 corresponding to grooves partitioned by a plurality of partition walls 11 in parallel in the width direction, and a narrow portion on one end side in the longitudinal direction. In this embodiment, further, in this embodiment, the communication path 14 communicated with the pressure generation chamber 12 by the ink supply path 13 and a reservoir that is a common ink chamber of the pressure generation chambers 12 are provided. The communication part 15 which comprises a part is formed.

  Here, the ink supply path 13 communicates with one end side in the longitudinal direction of the pressure generation chamber 12 and has a width smaller than that of the pressure generation chamber 12. For example, in the present embodiment, the ink supply path 13 is configured such that one side surface in the width direction is a plane continuous from the side surface of the pressure generation chamber 12, and the other side surface is inside the side surface of the pressure generation chamber 12. It is provided so that it may be located in. For example, a protruding portion 16 that protrudes inward from the side surface of the pressure generation chamber 12 is formed in the partition wall 11, and is formed with a width smaller than the width of the pressure generation chamber 12 by narrowing the ink flow path in the width direction. In the present embodiment, the ink supply path 13 is formed by narrowing the width of the ink flow path from one side. However, the ink supply path 13 may be formed by narrowing the width of the ink flow path from both sides.

  Further, each communication path 14 is formed between the ink supply path 13, the pressure generation chamber 12, and the communication portion 15 with substantially the same width as the pressure generation chamber 12. That is, each communication path 14 is formed by extending the partition walls 11 on both sides in the width direction of the pressure generating chamber 12 to the communication part 15 side to partition the space between the ink supply path 13 and the communication part 15. Yes. The ink flow path including the pressure generation chamber 12, the ink supply path 13, the communication path 14, the communication portion 15, and the like is formed by anisotropically etching the flow path forming substrate 10.

  Here, the ink supply path 13 plays a role of maintaining a constant flow path resistance of the ink flowing into the pressure generating chamber 12 from the communication portion 15 via the communication path 14. The size (width and length) of the ink supply path 13, in other words, the size of the overhanging portion 16 greatly affects the ink ejection characteristics, and thus high dimensional accuracy is required.

  For example, in the present embodiment, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110). Therefore, when the flow path forming substrate 10 is anisotropic wet-etched, the first perpendicular to the (110) plane is obtained. The (111) plane and the second (111) plane forming an angle of 70.53 ° with respect to the first (111) plane are difficult to remove. That is, the first and second (111) planes have a slower etching rate than the other planes. For this reason, the inner surface (side surface) of the ink flow path such as the pressure generating chamber 12 formed by anisotropic etching of the flow path forming substrate wafer 110 is basically the same as the first (111) surface and the first flow path. And two (111) planes. In the present embodiment, the ink flow path such as the pressure generating chamber 12 is formed along the first (111) plane. For this reason, as shown in FIG. 3, the overhang portion 16 forming the ink supply path 13 is a first surface (111) which is the first (111) surface and forms the side surface of the ink supply path 13, and the first surface. 16a and a second surface 16b connecting the side surface 12a of the pressure generating chamber 12 and the side surface 14a of the communication passage 14 which are the first (111) surface.

  Since the width of the ink supply path 13 is determined by the first surface 16a of the overhanging portion 16, which is the first (111) surface having a low etching rate, it can be formed with relatively high accuracy by etching. On the other hand, since the etching rate of the second surface 16b of the overhang portion 16 is relatively fast, if the flow path forming substrate 10 is etched to form an ink flow path such as the pressure generating chamber 12, the etching proceeds in the depth direction. At the same time, the second surface 16b of the overhang portion 16 is also etched (side-etched), making it difficult to form the overhang portion 16 having a predetermined length L1 with high accuracy.

  However, according to the manufacturing method of the present invention, the dimensional accuracy of the ink supply path 13 (the overhang portion 16), particularly the dimensional accuracy in the length direction, can be greatly improved. That is, the ink supply path 13 (projecting portion 16) having a desired length L1 can be formed with high accuracy. The production method of the present invention will be described in detail later.

  A nozzle plate 20 having a nozzle opening 21 is joined to the opening surface side of the flow path forming substrate 10 on which such an ink flow path is formed. Such a nozzle plate 20 is made of glass ceramics, a silicon single crystal substrate, stainless steel, or the like.

  An insulating film 55 having a thickness of, for example, about 0.4 μm is formed on the elastic film 50 on the surface of the flow path forming substrate 10. Further, on the insulator film 55, a lower electrode film 60 having a thickness of, for example, about 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 1.0 μm, and a thickness of, for example, about 0 A piezoelectric element 300 composed of an upper electrode film 80 of .05 μm is formed. Further, a lead electrode 90 is connected to the upper electrode film 80 of each piezoelectric element 300, and a voltage is selectively applied to each piezoelectric element 300 via the lead electrode 90. .

  Further, a protective substrate 30 having a piezoelectric element holding portion 31 is bonded to the surface of the flow path forming substrate 10 on the piezoelectric element 300 side through an adhesive 35 in a region facing the piezoelectric element 300. Since the piezoelectric element 300 is formed in the piezoelectric element holding part 31, it is protected in a state hardly affected by the external environment. In addition, as for the piezoelectric element holding | maintenance part 31, the space may be sealed and does not need to be sealed. The protective substrate 30 is formed with a reservoir portion 32 that constitutes the reservoir 100 in communication with the communication portion 15 of the flow path forming substrate 10.

  A driving IC 200 for driving the piezoelectric element 300 is mounted on the protective substrate 30. The leading end portion of each lead electrode 90 drawn from each piezoelectric element 300 to the outside of the piezoelectric element holding portion 31 is electrically connected to the drive IC 200 via the drive wiring 210.

  In addition, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30 to seal the reservoir portion 32. The region of the fixing plate 42 that faces the reservoir portion 32 is an opening 43 that is completely removed in the thickness direction, and the reservoir portion 32 is actually only a flexible sealing film 41. It is sealed with.

  In such an ink jet recording head according to the present embodiment, ink is taken in from an external ink supply unit (not shown), filled with ink from the reservoir 100 to the nozzle opening 21, and then subjected to pressure according to a recording signal from the driving IC 200. By applying a voltage between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the generation chamber 12 to bend and deform the piezoelectric element 300 and the diaphragm, the pressure in each pressure generation chamber 12 is increased. Ink is ejected from the opening 21.

  Hereinafter, a method for manufacturing such an ink jet recording head will be described with reference to FIGS. 4 to 6 are longitudinal sectional views of the pressure generating chamber showing the manufacturing process of the ink jet recording head, and FIGS. 7 and 8 are schematic perspective views for explaining the process of forming the ink flow path. It is.

First, as shown in FIG. 4A, a channel forming substrate wafer 110, which is a silicon wafer, is thermally oxidized in a diffusion furnace at about 1100 ° C., and a silicon oxide film 51 constituting an elastic film 50 is formed on the surface thereof. To do. In the present embodiment, a silicon wafer having a relatively thick and high rigidity of about 625 μm is used as the flow path forming substrate wafer 110. Next, as shown in FIG. 4B, an insulator film 55 made of zirconium oxide is formed on the elastic film 50 (silicon oxide film 51). Specifically, after a zirconium (Zr) layer is formed on the elastic film 50 (silicon oxide film 51) by, for example, a sputtering method, the zirconium layer is thermally oxidized in a diffusion furnace at 500 to 1200 ° C., for example. Thus, the insulator film 55 made of zirconium oxide (ZrO ₂ ) is formed. Next, as shown in FIG. 4C, for example, after the lower electrode film 60 is formed by laminating platinum and iridium on the insulator film 55, the lower electrode film 60 is patterned into a predetermined shape. Next, as shown in FIG. 4 (d), a piezoelectric layer 70 made of, for example, lead zirconate titanate (PZT) or the like, and an upper electrode film 80 made of, for example, iridium, are connected to the wafer 110 for flow path forming substrate. The piezoelectric element 300 is formed by patterning the piezoelectric layer 70 and the upper electrode film 80 in regions facing the pressure generation chambers 12.

  Next, as shown in FIG. 5A, a lead electrode 90 is formed. Specifically, for example, a wiring layer 95 made of, for example, gold (Au) or the like is formed on the entire surface, and the wiring layer 95 is patterned to form the lead electrode 90 drawn from each piezoelectric element 300.

  Next, as shown in FIG. 5B, the protective substrate wafer 130 is bonded to the flow path forming substrate wafer 110 by the adhesive 35. After bonding the protective substrate wafer 130 to the flow path forming substrate wafer 110 in this manner, as shown in FIG. 5C, the flow path forming substrate wafer 110 is polished to a certain thickness, A predetermined thickness is formed by wet etching with hydrofluoric acid.

  Next, as shown in FIG. 6A, a protective film 52 made of, for example, silicon nitride (SiN) is newly formed on the flow path forming substrate wafer 110 and patterned into a predetermined shape. By using the mask as a mask, the flow path forming substrate wafer 110 is anisotropically etched to form ink flow paths such as the pressure generation chamber 12, the ink supply path 13, the communication path 14, and the communication section 15.

  At this time, in the present invention, the ink flow path is formed by etching the flow path forming substrate wafer 110 in a plurality of stages, for example, in two stages. Specifically, first, as shown in FIG. 7A, the length L2 of the region facing each ink supply path 13, that is, the region serving as the overhanging portion 16, is the length of the overhanging portion 16 in the final shape. The protective film 52 is patterned so as to be longer than L1, and as shown in FIG. 7B, the elastic film 50 exposes the flow path forming substrate wafer 110 using the protective film 52 of such a predetermined pattern as a mask. An ink flow path such as the pressure generation chamber 12 is formed by performing anisotropic etching until the first etching step. In this first etching step, the length L3 of the overhanging portion 16 is made longer than the length L1 in the final shape.

  As described above, etching proceeds in the depth direction while the first (111) surface and the second (111) surface of the flow path forming substrate wafer 110 are exposed. Further, in a portion where the portions other than the first (111) surface and the second (111) surface are exposed, the etching proceeds in the surface direction (lateral direction). That is, the second surface 16b of the overhang portion 16 is etched (side-etched) in the lateral direction. In the first etching step, the length L3 of the overhang portion 16 is adjusted by adjusting the side etching amount according to the etching time.

  Next, as shown in FIG. 8A, at least a part of the end surface of the overhang portion 16 on the ink supply path 13 side, that is, at least a part of the first surface 16a is exposed on the protective film 52. A notch 52a is formed (mask processing step). In the present embodiment, the cutout portion 52a is formed in the protective film 52 so that the second surface 16b is completely exposed together with a part of the first surface 16a of the overhang portion 16. The method for forming the cutout 52a in the protective film 52 is not particularly limited, but it is preferable to form the cutout 52a in the protective film 52 by, for example, laser processing. Thereby, the notch 52a can be formed relatively easily and with high accuracy. Next, as shown in FIG. 8B, the flow path forming substrate wafer 110 is anisotropically etched using the protective film 52 having the notches 52a as a mask, so that the overhanging portion 16 has a predetermined length L1. Form. That is, a portion of the flow path forming substrate wafer 110 facing the notch 16 is removed so that the overhang 16 has a predetermined length L1 (second etching step).

  At this time, the flow path forming substrate wafer 110 (the overhanging portion 16) is etched starting from intersections P1 and P2 between the end surface of the cutout portion 52a and the first surface 16a of the overhanging portion 16 (FIG. 8A). )reference). Therefore, the length of the overhang portion 16 can be controlled with extremely high accuracy.

  For example, in the first etching step, the length L3 of the overhang portion 16 is likely to vary, and thereafter, the second surface 16b of the overhang portion 16 formed in the first etching step is further etched (side etching). Thus, if the overhang portion 1 is to be formed to the predetermined length L1, there is a possibility that the dimensional accuracy of the final overhang portion 16 may be reduced due to the variation in length in the first etching step. . However, in the present invention, since the second etching step described above is performed after the first etching step, the dimensional accuracy of the overhang portion 16 is greatly improved. That is, in the second etching process, since the etching proceeds from the intersections P1 and P2, the protruding portion 16 is increased to a predetermined length L1 regardless of variations in the length of the protruding portion 16 in the first etching process. It can be formed with high accuracy. Specifically, in the case where the overhanging portion 16 having a length of 100 μm is formed, the dimensional error can be suppressed within ± 10 μm.

  In the present embodiment, since the notch 52a having a relatively large area where the second surface 16b is completely exposed together with a part of the first surface 16a of the overhanging portion 16 is formed in the protective film 52, the first In the second etching step, the flow path forming substrate wafer 110 (the overhanging portion 16) can be satisfactorily removed in a relatively short time. However, for example, as shown in FIG. 9, the cutout portion 52a only needs to expose the end surface of the overhang portion 16 on the ink supply path 13 side, that is, a part of the first surface 16a. Even in this case, since the starting point of the etching in the second etching step is the intersection points P3 and P4, as described above, the overhanging portion 16 can be formed with a predetermined length L1 with high accuracy.

  Although not shown, after that, for example, the protective film 52 is removed, and the nozzle plate 20 in which the nozzle openings 21 are formed on the surface of the flow path forming substrate wafer 110 opposite to the protective substrate wafer 130 is provided. At the same time, the compliance substrate 40 is bonded to the protective substrate wafer 130. Then, unnecessary portions of the outer peripheral edge portions of the flow path forming substrate wafer 110 and the protective substrate wafer 130 are removed by cutting, for example, by dicing, and the flow path forming substrate wafer 110 and the like are shown in FIG. The ink jet recording head having the above-described structure is manufactured by dividing the flow path forming substrate 10 having one chip size.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to these embodiment. For example, the present invention has been described with reference to an example of a method for manufacturing an ink jet recording head, but the present invention is not limited to this, and the present invention is intended for a wide range of methods for manufacturing a liquid ejecting head. Of course, the present invention can also be applied to a method for manufacturing a jet. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (surface emitting displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

  In addition to the manufacturing of the liquid jet head described above, the present invention is adopted when a groove and a narrow groove having a narrower width than the groove are formed in the silicon substrate by anisotropic etching. can do.

FIG. 3 is an exploded perspective view of the recording head according to the first embodiment. 2A and 2B are a schematic plan view and a cross-sectional view of the recording head according to the first embodiment. 3 is a plan view of a flow path forming substrate according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a schematic perspective view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a schematic perspective view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. FIG. 9 is a schematic perspective view illustrating a modification of the manufacturing process of the recording head according to the first embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 12 Pressure generation chamber, 13 Ink supply path, 14 Communication path, 15 Communication part, 16 Overhang | projection part, 16a 1st surface, 16b 2nd surface, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board, 40 compliance substrate, 52 protective film, 52a notch, 110 wafer for flow path forming substrate, 300 piezoelectric element

Claims (7)

Processing a silicon substrate in which a groove having a predetermined width and a narrow groove having a narrow portion having a predetermined length that is narrower than the groove and provided in a part of the groove in the longitudinal direction are formed on the silicon substrate by anisotropic etching A method,
The narrow groove is formed such that a protective film having a predetermined shape is formed on the silicon substrate and the silicon substrate is anisotropically etched using the protective film as a mask so that the length of the narrow portion becomes longer than the predetermined length. A first etching step for forming the protrusion, and the protective film in a region corresponding to the protrusion that is provided to protrude from the side surface of the groove to the inside of the narrow groove to form the narrow portion. A mask processing step of forming a cutout portion so that at least a part of the end face on the narrow portion side is exposed, and the silicon substrate is anisotropically etched using the protective film having the cutout portion as a mask. And a second etching step in which the narrow portion has the predetermined length. 2. The method for processing a silicon substrate according to claim 1, wherein, in the mask processing step, the notch portion is formed so that at least a part of an end surface of the projecting portion on the groove portion side is exposed. 3. The method for processing a silicon substrate according to claim 1, wherein, in the mask processing step, the notch is formed in the protective film by laser processing. The method for processing a silicon substrate according to claim 1, wherein the protective film is made of silicon nitride (SiN). 5. The method for processing a silicon substrate according to claim 1, wherein the silicon substrate is a silicon single crystal substrate whose surface is a (110) plane. 6. The method for processing a silicon substrate according to claim 1, wherein the narrow groove is formed along a (111) plane perpendicular to a (110) plane. A flow path forming substrate having a flow path including a pressure generation chamber made of a silicon substrate and communicating with the nozzle and a supply path having a narrower width than the pressure generation chamber, and a pressure for discharging droplets into the pressure generation chamber A method of manufacturing a liquid ejecting head having pressure generating means for generating
As the step of forming the flow path on the flow path forming substrate, a protective film having a predetermined shape is formed on the flow path forming substrate, and the flow path forming substrate is anisotropically etched using the protective film as a mask. A first etching step for forming the flow path such that the length of the supply path is longer than the predetermined length; and the supply path is provided so as to protrude from the side surface of the pressure generation chamber to the inside of the flow path. A mask processing step of forming a cutout portion in the protective film in a region corresponding to the overhang portion forming the cutout so as to expose at least a part of the end surface on the supply path side of the overhang portion, and the cutout portion. And a second etching step of anisotropically etching the flow path forming substrate using a protective film as a mask to set the supply path to the predetermined length. Method.

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