JP2005144850A - Method of manufacturing inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an inkjet recording head capable of adequately forming an ink supply hole without losing a sacrifice layer. <P>SOLUTION: The sacrifice layer 18 made of a metallic material such as, for example, an aluminum alloy is provided on an Si substrate 10 corresponding to a position having an ink supply hole formed thereon. Preferably, the sacrifice layer 18 is formed of a material the same as that of a first metallic wiring 20 (a wiring layer) at the same time of forming the wiring. As a result, it is possible to prevent the sacrifice layer 18 from being lost, thereby adequately forming the ink supply hole. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an ink jet recording head used in an ink jet recording apparatus.

  In recent years, the spread of color documents in offices is remarkable, and various output devices have been proposed. Among them, downsizing is possible, and the low-cost inkjet method is used as a powerful recording method in various output devices.

  The manufacturing method of a recording head used in such an ink jet method is basically a process of performing an etching process on the surface of a Si substrate made of a silicon wafer, similarly to a semiconductor manufacturing method such as LSI.

  For example, in the case of the ink jet recording head as shown in FIG. 7, it is necessary to form the ink supply port 144 for supplying ink from the back surface of the Si substrate 100 as shown in FIG. The mask pattern 110 is formed in advance, and anisotropic etching is performed with a chemical such as KOH (potassium hydroxide) or TMAH (tetramethylammonium hydroxide) to accurately form the ink supply port 108.

  As a process order, after forming the heater 102, its protective film 104, and the nozzle 106 on the Si substrate 100, the ink supply port 108 is opened from the back side of the Si substrate 100, and the ink flow path 112 is formed.

  The position and size of the ink supply port 108 are determined by the mask pattern 110 on the back surface of the Si substrate 100. However, the opening size and position of the ink supply port 108 may vary depending on etching variations, misalignment of the mask pattern 110, and the like. It may shift from the target position, causing a decrease in yield.

  In addition, when the inlet supply port 108 is formed, the etching solution (TMAH, KOH, etc.) wraps around the surface of the Si substrate 100 (on the heater 102 side), causing damage due to the etching solution, resulting in a decrease in yield. .

In order to solve such problems, Japanese Patent Laid-Open No. 10-1811032 proposes a method in which a layer called a sacrificial layer is deposited in advance at the position of the inlet opening (ink supply port) to make the opening size constant. ing.
Japanese Patent Application Laid-Open No. 2002-337347 proposes a method of introducing impurities into the surface of the silicon substrate in the through hole (ink supply port) portion (forming a damage layer) and controlling the size of the through hole.
Japanese Laid-Open Patent Publication No. 2003-136491 proposes a method of forming an oxide film and a silicon nitride film in a through-hole (ink supply port) portion to prevent damage to the surface due to the surrounding of a chemical solution when forming the through-hole. .
Japanese Patent Application Laid-Open No. 2003-136492 proposes a method of forming a silicon nitride film so as to cover an oxide film in a through hole (ink supply port) portion, and preventing damage to the surface due to the surrounding of a chemical solution when the through hole is formed. doing.

JP 10-1811032 A JP 2002-337347 A JP2003-136491A JP 2003-136492 A

  However, a method of using Poly-Si as a sacrificial layer as a sacrificial layer as typified by JP-A-10-1811032 is a good improvement method, but its manufacturing process becomes very complicated. In addition, the passivation film (insulating film) deposited on the sacrificial layer may be reduced in a subsequent process, and the effect may be lost. Hereinafter, two problems will be described with reference to the drawings.

  Problem 1: FIG. 8 is a process diagram illustrating a normal Poly-Si process. Usually, Poly-Si is used as a gate electrode of a logic circuit (LOGIC).

  First, as shown in FIG. 8A, a thin oxide film 122 (damage countermeasure) and a nitride film 124 are deposited on the Si substrate 120. Next, as shown in FIG. 8B, a resist 126 is spin-coated. Next, as shown in FIG. 8C, the nitride film 124 is etched using the resist 126 as a mask to form a desired pattern. Next, as shown in FIG. 8D, an oxidation process is performed at 1000 ° C., for example, to form a field oxide film 128. An oxide film 130 is formed on the back surface of the Si substrate 120. Thereafter, as illustrated in FIG. 8E, Poly-Si is formed as the gate oxide film 132 and the gate electrode 134.

  In this way, normal Poly-Si is formed as described above, but the problem is the gate oxide film 132 under the Poly-Si. If the gate oxide film 132 exists, if the silicon substrate is anisotropically etched from the back side, the etching is stopped at the gate oxide film 132.

  Therefore, Poly-Si as a sacrificial layer as used in JP-A-10-1811032 must be formed separately from the Poly-Si of the gate electrode 134. The process becomes complicated and leads to cost increase.

  Problem 2: After Poly-Si is formed as a sacrificial layer, Poly-Si may be reduced or lost in subsequent steps (heater formation, wiring formation, etc.) and may not serve as a sacrificial layer. It is.

  FIG. 9 is a process diagram showing how Poly-Si is reduced or disappears in a subsequent process (heater formation, wiring formation, etc.) after Poly-Si is formed as a sacrificial layer.

  First, as shown in FIG. 9A, after forming Poly-Si serving as the sacrificial layer 136 on the Si substrate 120 on which the logic circuit and the field oxide film 128 are formed, the interlayer insulating film 138 and the first metal are formed. A wiring 140 is formed. Due to the over-etching at the time of forming the first metal wiring 140, the interlayer insulating film 138 is reduced. A gate electrode (Poly-Si) that can be used in the logic circuit is not shown. The interlayer insulating film 138 is generally 0.8 to 1.0 μm, and the film reduction when forming the first metal wiring 140 is about 0.2 to 0.3 μm at maximum.

  Next, as shown in FIG. 9B, an interlayer insulating film 142 is deposited, and necessary portions such as the contact hole 144 of the first metal wiring 140 are patterned. At this time, the interlayer insulating film 142 in the sacrificial layer 136 portion is also removed to provide an opening 146, but the interlayer insulating film 138 is also removed by over-etching at that time.

  Next, as shown in FIG. 9C, the second metal wiring 148 and the heater 150 are deposited and desired patterning is performed. By the etching at this time, the interlayer insulating film 138 formed on the sacrificial layer 136 is almost lost due to the film reduction, and is etched down to the poly-Si of the sacrificial layer 136.

  Then, as shown in FIG. 9D, the P-SiN film 152 and the Ta film 154 as protective films are deposited and patterned, but at this point, the Poly-Si as the sacrificial layer 136 disappears completely. It will be.

  In order to avoid the loss of Poly-Si as the sacrificial layer 136 as described above, there is a method of performing the process without opening the interlayer insulating film 142 on the sacrificial layer 136 (see FIG. 9B). In this case, the insulating film (interlayer insulating film) on Poly-Si as the sacrificial layer 136 is finally too thick (this insulating film must also be finally removed). Depending on the etching method, a secondary failure such as an abnormality occurring in another pattern may occur.

  Accordingly, an object of the present invention is to solve the conventional problems and achieve the following object. That is, an object of the present invention is to provide a method for manufacturing an ink jet recording head capable of forming an ink supply port satisfactorily without sacrificing a sacrificial layer.

The above problem is solved by the following means. That is,
The manufacturing method of the ink jet recording head of the present invention includes:
A heating resistor, a circuit element for driving the heating resistor, and a substrate having an ink supply port;
An orifice body provided on the first main surface side of the substrate having the heating resistor and having an ink discharge port;
An inkjet recording head manufacturing method comprising:
Forming the circuit element on a first main surface on the substrate;
Forming a sacrificial layer made of a metal material on the first main surface of the substrate corresponding to the formation position of the ink supply port;
Forming a wiring layer on the first main surface on the substrate to electrically connect the heating resistor and the circuit element;
Etching the substrate from the second main surface side opposite to the first main surface and etching the sacrificial layer to form the ink supply port;
It is characterized by having.

  In the method for manufacturing an ink jet recording head of the present invention, the sacrificial layer is made of a metal material. Even when exposed, the sacrificial layer does not disappear.

  In the method for manufacturing an ink jet recording head of the present invention, it is preferable that the sacrificial layer is formed of a material mainly composed of aluminum. Preferably, the step of forming the sacrificial layer and the step of forming the wiring layer are performed simultaneously, and the sacrificial layer and the wiring layer are preferably made of the same material.

  When the sacrificial layer is made of a material mainly composed of aluminum, the sacrificial layer functions well without disappearing. Further, by forming the wiring layer with the same material at the same time, the number of steps can be reduced and the cost can be reduced.

  In the recording method of the ink jet recording head of the present invention, the sacrificial layer is preferably formed directly on the substrate.

  By forming the sacrificial layer directly on the substrate without passing through another film such as an insulating film, the sacrificial layer is continuously etched away from the second main surface side (back surface side) when forming the ink supply port. Therefore, it can function well as a sacrificial layer. If another film is interposed between the sacrificial layer and the substrate, the etching is stopped at the other film when the ink supply port is formed, and the number of processes is increased.

  The method for manufacturing an ink jet recording head of the present invention may further include a step of forming an insulating layer on the sacrificial layer.

  For example, by forming an insulating layer on the sacrificial layer together with the interlayer insulating film of the wiring layer, the insulating layer can function as an etching stopper layer when the sacrificial layer is removed.

  Moreover, you may have the process of removing a part of said insulating layer and adjusting the film thickness of the said insulating layer formed on the said sacrificial layer.

  Removal of the insulating layer after removal of the sacrificial layer by removing a part of the insulating layer on the sacrificial layer so that the insulating layer has an optimum thickness that functions as an etching stopper layer when the sacrificial layer is removed. Time can be shortened and another pattern abnormality can be prevented.

  The insulating layer can be selected from an oxide film, a nitride film, and a resin film. In order to function as an etching stopper layer when removing the sacrificial layer, the insulating layer preferably has a thickness of 0.3 μm or more.

  The present invention will be described below with reference to the drawings. Note that members having substantially the same function are given the same reference numerals throughout the drawings.

(First embodiment)
1 to 3 are process diagrams showing a method of manufacturing an ink jet recording head according to the first embodiment of the present invention.

  In this embodiment, first, as shown in FIG. 1A, a logic circuit manufacturing process is performed on the surface (first main surface) of the Si substrate 10 (<100> substrate, thickness 550 μm), and a heater described later A circuit element for driving 26 is formed. Note that the logic circuit manufacturing process is performed in a well-known semiconductor process, and thus is omitted in this embodiment. However, only a field thermal oxide film 14 (LOCOS: Local Oxidation of Silicon) which is an element isolation layer is illustrated in the drawing.

  Next, a BPSG (Boro-Phospho-Silicate Glass) film as an interlayer insulating film 16 (oxide film) is deposited on the surface side of the Si substrate 10 by 0.8 μm, and a desired position of the sacrificial layer 18 is deposited. Open with a pattern. At this time, it is removed properly so that the interlayer insulating film 16 does not remain. Here, if the interlayer insulating film 16 remains thin, the sacrificial layer 18 is formed on the Si substrate 10 via the oxide film, and the back surface (second main surface) of the Si substrate 10 when the ink supply port 42 is formed. ) Will affect the etching.

  Next, an aluminum alloy is deposited by a sputtering method, and a photolithography process, for example, a dry etching process using a chlorine-based gas is sequentially performed and patterned to form the first metal wiring 20 (wiring layer). At the same time, the sacrificial layer 18 is also formed. Thereby, the sacrificial layer 18 made of a material mainly composed of aluminum is formed simultaneously with the first metal wiring 20. The thickness of the sacrificial layer 18 is preferably 0.5 to 1.0 μm.

  Then, as shown in FIG. 1B, a laminated film of P—SiO / P-TEOS is deposited as an interlayer insulating film 22 on the surface side of the Si substrate by 1.0 μm, and a photolithography process, for example, a fluorine-based gas is used. A dry etching step is sequentially performed to form a contact hole 24 to the first metal wiring 20.

  Next, as shown in FIG. 1C, for example, TaSiO is deposited on the interlayer insulating film 22 by sputtering, and a photolithography process, for example, an etching process using a fluorine-based gas is sequentially performed and patterned. A heater 26 (heating resistor) connected to one metal wiring 20 through a contact hole 24 is formed. Then, an aluminum alloy film is formed by sputtering, and a photolithography process, for example, a dry etching process using a chlorine-based gas, is sequentially performed and patterned, so that the second metal wiring 28 (wiring layer) is formed so that at least the heat generation region of the heater 26 is opened. ).

  Here, when the heater 26 and the second metal wiring 28 are patterned, the interlayer insulating film 22 is etched by etching, but the thickness is about 0.2 to 0.3 μm, and the remaining of the interlayer insulating film 22 on the sacrificial layer 18 is left. The membrane is sufficient.

  Next, as shown in FIG. 1D, a P-SiN film 30 and a Ta film 32 are formed as a heater protection film on the second metal wiring 28 and the exposed heater 26.

  Next, as shown in FIG. 2E, a 1.0 μm thick P-SiO film 34 is deposited on the back surface (second main surface) of the Si substrate 10 by the P-CVD method. On the other hand, on the back surface (second main surface) side of the Si substrate 10, a PMGI resist (MicroChem) is formed as a mold material 36 by spin coating, and an epoxy resin (SU-8) is further covered so as to cover the mold material 36. The coating resin layer 38 is formed by spin coating. Here, as the mold member 36, for example, a resin that is soluble in a solvent is used so that it can be removed in a later step.

  Next, as shown in FIG. 2F, a resist pattern (OFPR800 manufactured by Tokyo Ohka Kogyo Co., Ltd .: not shown) is formed on the surface of the P-SiO film 34 formed on the back surface of the Si substrate 10, and CF-based dry etching (AMJ) is performed. A mask pattern 40 is formed by patterning the P-SiO film 34 by using Precision 5000 Etch.

  Next, as shown in FIG. 3 (g), the Si substrate 10 is immersed in a TMAH (tetramethylammonium hydroxide) solution (80 ° C., 15 hours), and the Si substrate 10 is removed by etching from the back surface. 42 is formed. At this time, the sacrificial layer 18 is also etched away immediately after penetrating the Si substrate 10 by etching, and the etching is stopped by the interlayer insulating film 22 on the sacrificial layer 18.

  Then, as shown in FIG. 3H, the interlayer insulating film 22 formed on the sacrificial layer 18 is removed with hydrofluoric acid from the back side of the Si substrate 10 to completely penetrate the ink supply port 42. . Thereafter, nozzles 44 (ink discharge ports) corresponding to the heaters 26 are formed in the coating resin layer 38, the mold material 36 is removed with an organic solvent to form ink channels 47, and an orifice plate made of the coating resin layer 38. 46 (orifice body) is formed.

  In this way, the ink jet recording head is manufactured.

  As described above, in this embodiment, since the sacrificial layer 18 is made of an aluminum alloy, even if the sacrificial layer is exposed due to film loss or the like of the interlayer insulating film 22 formed on the sacrificial layer 18, the sacrificial layer is formed. The ink supply port 42 is reliably formed by the sacrificial layer 18 with high dimensional accuracy without disappearing.

  In the present embodiment, since the sacrificial layer 18 is formed of the same material at the same time as the first metal wiring 20 is formed, the number of processes can be reduced and the cost can be reduced.

  In this embodiment, since the sacrificial layer 18 is formed directly on the Si substrate 10 without the interlayer insulating film 16 interposed therebetween, the Si substrate 10 and the sacrificial layer 18 are continuously formed when the ink supply port 42 is formed. Thus, the ink supply port 42 can be formed without increasing the number of steps.

  Further, when the ink supply port 42 is formed, immediately after the ink supply port 42 penetrates the Si substrate 10, the sacrificial layer 18 is etched by the etching liquid (TMAH), and the etching liquid circulates not only from the back surface but also from the front surface. Although etching may proceed, in this embodiment, the interlayer insulating film 22 formed on the sacrificial layer 18 functions as an etching stopper layer, and the etching solution does not damage other patterns.

  Here, the thickness of the insulating layer (in this embodiment, the interlayer insulating film 22) formed on the sacrificial layer 18 as an etching stopper layer is such that no pinholes are generated, that is, 0.3 μm or more (preferably 0.3 mm). 5 to 1.0 μm). However, since the insulating layer (interlayer insulating film 22 in the present embodiment) may be reduced by etching in the patterning of the heater 26 and the second metal wiring as described above, the ink supply port It is preferable that the remaining film be formed with a thickness that does not cause pinholes when forming 42, that is, a thickness of 0.3 μm or more (preferably 0.5 to 1.0 μm).

(Second Embodiment)
4 to 6 are process diagrams showing a method of manufacturing an ink jet recording head according to the second embodiment of the present invention.

  In the present embodiment, the metal wiring structure has a three-layer structure. In the present embodiment, from FIG. 4A to FIG. 4B, as in FIG. 1A to FIG. 1B in the first embodiment, the first metal wiring 20, the sacrificial layer 18, Interlayer insulating films 16, 22 and contact holes 24 are formed.

  Next, as shown in FIG. 4C, an aluminum alloy film is deposited on the interlayer insulating film 22 by a sputtering method, and a photolithography process, for example, a dry etching process using a chlorine-based gas is sequentially performed to form a second pattern. Metal wiring 28 (wiring layer) is formed. Then, a P-SiO / P-TEOS laminated film of 1.0 μm is deposited as the interlayer insulating film 48, and a photolithography process, for example, a dry etching process using a fluorine-based gas is sequentially performed, and a contact hole 50 to the second metal wiring 28 is formed. Form. At this time, the interlayer insulating film 48 on the sacrificial layer 18 is also removed by etching to provide an opening 52.

  Next, as shown in FIG. 4D, for example, TaSiO is deposited on the interlayer insulating film 48 by a sputtering method, and an photolithography process, for example, an etching process using a fluorine-based gas is sequentially performed and patterned. The heater 26 (heating resistor) connected to the two metal wirings 28 through the contact holes 50 is formed. Then, an aluminum alloy film is formed by sputtering, and a photolithography process, for example, a dry etching process using a chlorine-based gas, is sequentially performed and patterned, so that the third metal wiring 54 (wiring layer) is formed so that at least the heating region of the heater 26 is opened. ).

  After this step, as shown in FIGS. 4 (e) to 6 (i), the same procedure as in FIGS. 1 (d) to 3 (h) in the first embodiment is performed to manufacture an ink jet recording head. .

  As described above, in this embodiment, two insulating layers of the interlayer insulating films 22 and 48 are formed on the sacrificial layer 18, and the sacrificial layer 18 is too thick as an etching stopper layer. Therefore, part of the insulating layer formed on the sacrificial layer 18 (in this embodiment, the interlayer insulating film 48) is removed to adjust the film thickness. For this reason, it is possible to shorten the removal time when removing the insulating layer after removing the sacrificial layer 18 and to prevent another pattern abnormality.

  Even if the sacrificial layer 18 is exposed by over-etching in this etching removal, the sacrificial layer 18 is made of a metal material (in this embodiment, an aluminum alloy), and therefore does not disappear.

  In any of the above-described embodiments, the form in which the sacrificial layer is made of an aluminum alloy has been described. However, the embodiment is not limited to this. For example, the sacrificial layer may be made of an alloy such as Ta, Zn, Cu, or W.

  In the present embodiment, the form in which the sacrificial layer is formed together with the formation of the first metal wiring has been described. However, the present invention is not limited to this. For example, when the metal wiring has a multi-layer structure, A sacrificial layer may be formed at the time of wiring formation.

FIG. 5 is a process diagram illustrating a method for manufacturing the ink jet recording head according to the first embodiment of the present invention. FIG. 5 is a process diagram illustrating a method for manufacturing the ink jet recording head according to the first embodiment of the present invention. FIG. 5 is a process diagram illustrating a method for manufacturing the ink jet recording head according to the first embodiment of the present invention. It is process drawing which shows the manufacturing method of the inkjet recording head which concerns on the 2nd Embodiment of this invention. It is process drawing which shows the manufacturing method of the inkjet recording head which concerns on the 2nd Embodiment of this invention. It is process drawing which shows the manufacturing method of the inkjet recording head which concerns on the 2nd Embodiment of this invention. It is a schematic sectional drawing which shows the structure of the conventional inkjet recording head. It is process drawing explaining the process of normal Poly-Si. FIG. 4 is a process diagram showing a state where Poly-Si is reduced or disappears in a subsequent process (heater formation, wiring formation, etc.) after Poly-Si is formed as a sacrificial layer.

Explanation of symbols

10 substrate 14 field thermal oxide film 16 interlayer insulating film 18 sacrificial layer 20 first metal wiring (wiring layer)
22 Interlayer insulation film (insulation layer)
24 Contact hole 26 Heater 28 Second metal wiring (wiring layer)
30 P-SiN film 32 Ta film 34 P-SiO film 36 Mold material 38 Coating resin layer 40 Mask pattern 42 Ink supply port 44 Nozzle (ink discharge port)
46 Orifice plate (orifice body)
47 Ink channel 48 Interlayer insulating film 50 Contact hole 52 Opening 54 Third metal wiring

Claims (8)

A heating resistor, a circuit element for driving the heating resistor, and a substrate having an ink supply port;
An orifice body provided on the first main surface side of the substrate having the heating resistor and having an ink discharge port;
In a method of manufacturing an inkjet recording head comprising:
Forming the circuit element on a first main surface on the substrate;
Forming a sacrificial layer made of a metal material on the first main surface of the substrate corresponding to the formation position of the ink supply port;
Forming a wiring layer on the first main surface on the substrate for electrically connecting the heating resistor and the circuit element;
Etching the substrate from the second main surface side opposite to the first main surface and etching the sacrificial layer to form the ink supply port;
An ink jet recording head manufacturing method comprising:   2. The method of manufacturing an ink jet recording head according to claim 1, wherein the sacrificial layer is formed of a material mainly composed of aluminum.   2. The inkjet according to claim 1, wherein the step of forming the sacrificial layer and the step of forming the wiring layer are performed at the same time, and the sacrificial layer and the wiring layer are made of the same material. A manufacturing method of a recording head.   The method of manufacturing an ink jet recording head according to claim 1, wherein the sacrificial layer is directly formed on the substrate.   The method of manufacturing an ink jet recording head according to claim 1, further comprising a step of forming an insulating layer on the sacrificial layer.   6. The method of manufacturing an ink jet recording head according to claim 5, further comprising a step of removing a part of the insulating layer and adjusting a film thickness of the insulating layer formed on the sacrificial layer.   6. The method of manufacturing an ink jet recording head according to claim 5, wherein the insulating layer is selected from an oxide film, a nitride film, and a resin film.   The method of manufacturing an ink jet recording head according to claim 5, wherein the insulating layer has a thickness of 0.3 μm or more.

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