JP3957920B2 - Inkjet head manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present inventionFor manufacturing method of inkjet headIt is related.
[0002]
[Prior art]
  As an etching method used for micromachining, a chemical etching technique based on a photolithography technique is mainly used. Here, as a substrate to be used, a silicon (Si) substrate (wafer) having crystal orientations of <100> and <110> planes is generally used. By performing alkaline chemical etching on the Si substrate having the above-described plane orientation, the depth (digging) direction and the width (spreading) direction can be selected with respect to the etching progress direction. Anisotropy of etching is obtained. For example, a hole having a deep and narrow shape can be formed. Further, when a substrate having a crystal orientation of <100> plane is used, the depth direction can be controlled because the depth direction is geometrically determined by the etching width. For example, etchingApplyIt is possible to obtain a hole that becomes narrower with an inclination of 54.7 ° in the depth direction from the surface. Therefore, by considering the thickness of the substrate and the etching width, the formation of holes up to the middle of the substrate can be reliably and easily controlled without penetrating the substrate (see FIG. 4).
It is well known that the etching properties described above are applied to micromachining techniques such as the manufacture of inkjet heads and pressure sensors.
[0003]
[Problems to be solved by the invention]
By the way, chemical etching with an alkaline etching solution is generally performed with a strong alkali for a long time, and further, during this time, heat treatment is performed.₂In general, a dielectric film such as a SiN film is used.
However, since these films are usually formed as deposited films such as sputtering and CVD, it is difficult to form these films without defects, and the head or the like is defective due to this defective portion (pinhole). There was sometimes. In addition, the miniaturization of processing advances year by year, so that there are circumstances in which minute defects cannot be ignored.
As described above, in micromachining technology such as head manufacturing, the formation of a defect-free etching mask is becoming a great demand.
[0004]
  Therefore, the present invention solves the above-described problems, can use a mask material that has alkali resistance and does not cause defects such as pinholes, and can perform highly reliable etching.NaNJJTojeIt is an object of the present invention to provide a method for manufacturing a lid.
[0006]
  In order to achieve the above object, the present invention is characterized in that an ink jet head manufacturing method is configured as follows.
That is, the present invention is a method of manufacturing an inkjet head for discharging ink,
  Preparing a silicon substrate provided with an electrothermal conversion element for discharging ink;
  Etching the substrateApplyProviding an etching resistant mask having a desired opening pattern on the surface;
  Providing an ink supply port penetrating the substrate by anisotropically etching the substrate through the etching-resistant mask using an alkaline solution, and
  The step of providing the etching resistant mask includes:
  Applying a polyetheramide on the surface of the substrate to form a polyetheramide resin layer;
  Forming a resist pattern as a mask for etching the polyetheramide resin layer on the polyetheramide resin layer by a photolithography process;
  The opening pattern is formed in the polyetheramide resin layer by dry-etching the polyetheramide resin layer using an etching gas mainly composed of a mixed gas of oxygen and carbon tetrafluoride with the resist pattern as a mask. And a process of
  It is characterized by having.
In addition, the ink jet head manufacturing method of the present invention is characterized in that a member for forming an ink flow path is formed on the substrate..
MaIn addition, the ink jet head manufacturing method of the present invention is characterized in that the resist pattern is removed after the opening pattern is formed in the polyetheramide resin layer.
The method for producing an inkjet head of the present invention is characterized in that N-methylpyrrolidone is used as a solvent in the etching of the polyetheramide resin layer.
In addition, the method of manufacturing an ink jet head according to the present invention is characterized in that the resist pattern is formed of a silicon-containing photoresist.
In the method for manufacturing an ink jet head according to the present invention, the amount of carbon tetrafluoride added is 5% to 15% with respect to the flow rate of oxygen.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
According to the configuration of the present invention described above, the polyetheramide resin used in the present invention has high strength and flexibility, high relaxation against external stress, excellent chemical resistance, acid, alkali, It is not attacked by aromatic solvents, etc., and has excellent heat resistance and moisture resistance, can be dissolved in a polar solvent to form a varnish, and can be formed at a relatively low temperature by simply blowing off the solvent. Since it is a material, for example, by using a polyetheramide resin layer as a mask when etching a substrate constituting an ink jet head, defects such as pinholes generated in the mask during mask formation can be reduced.
In addition, in the present invention, by using a two-layer structure in which a polyetheramide resin layer is formed on a dielectric layer as the mask, it is possible to reduce the above-mentioned defects and, for example, accuracy in anisotropic etching. Etching can be performed with good quality.
[0009]
In addition, since the polyetheramide resin itself has no photosensitivity, in general, a dispenser or screen printing is used to pattern the polyetheramide resin. Therefore, polyether amide resin can be used for applications such as moisture-proof coatings for electronic parts, etc., where fine patterning has never been required, but requires fine patterning. It has been difficult to use as an etching mask in a micromachining technique or the like, or as a protective film as an ink resistant layer of an ink jet recording head. This is because, in order to perform fine patterning on the polyetheramide resin, even if an attempt is made to cover the polyetheramide resin with an etching mask and dissolve the unnecessary portion with a solvent, the polyetheramide resin can be dissolved in a solvent. This is because there was no suitable masking material to withstand. However, according to the dry etching method of the polyetheramide resin layer of the present invention, since fine patterning is possible, it can be applied to a protective film as an ink-resistant layer of an ink jet recording head that requires such fine patterning. It can be used.
[0010]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[Example 1]
(A)-(d) is a figure which shows the structure of the inkjet head which concerns on Example 1 of this invention, (b) is AA 'sectional drawing of Fig.1 (a), (c) is the Si. A schematic plan view of the substrate portion, (d) is a schematic cross-sectional view of the Si substrate portion.
In FIG. 1A and FIG. 1B, the inkjet head includes a discharge port plate 5 provided with a discharge port 6 corresponding to the electrothermal conversion element 5, and a Si substrate for supplying ink from the back surface of the Si substrate 1. 1 includes a side shooter type ink jet head that has an ink supply port 4 opened at 1 and ejects ink substantially perpendicularly to the substrate surface.
[0011]
In FIG. 1C, an electrothermal conversion element and an ink flow path for generating thermal energy used for ink ejection shown in FIGS. 1A and 1B are provided on a substrate surface 1A on one side of the substrate 1. A forming member is formed. In addition, an ink supply port 4 as a through hole is formed in the center of the substrate 1, whereby ink can be supplied to the ink flow path on the surface 1 </ b> A side from the back surface of the substrate 1. In addition, in the same figure, the code | symbol 3 shows the polyetheramide resin layer for mask patterns formed in the manufacturing process shown below.
[0012]
  2A to 2C are schematic views showing a part of the manufacturing process of the ink jet head according to the present embodiment.
First, as shown in FIG. 2A, etching is performed using a <100> -plane Si substrate 1.ApplyA polyetheramide resin layer 3 is formed on the surface 1B side by spin coating.
In one embodiment of the present invention, a thermoplastic polyether amide (manufactured by Hitachi Chemical Co., Ltd., trade name: HL-1200) was used as the polyether amide resin layer 3.
The above-mentioned thermoplastic polyether amide is commercially available as a solution dissolved in a solvent, and after forming this to a desired film thickness by spin coating, the solvent component is removed by heating and drying to obtain a thermoplastic polyether amide resin. Layer 3 can be formed. Here, regarding the setting of the film thickness to be applied, in view of obtaining a defect-free etching mask that is the object of the present invention, since a correlation is seen between the film thickness and the defect occurrence rate, It has been confirmed that if the film thickness is 2 μm or more, it is effective.
[0013]
Next, as shown in FIG. 2 (b), an etching mask pattern is formed by the thermoplastic polyetheramide resin layer 3. This formation is performed as follows. When the thermoplastic polyether amide used in this example is used as a material for the resin film 3, since this material is not provided with a photosensitive component, first, in order to form a pattern of the thermoplastic polyether amide, A resist pattern (not shown) is formed by photolithography using a separate photoresist.
Then, the thermoplastic polyether amide is etched using this resist pattern to form an etching mask shown in FIG. In this case, the etching of the thermoplastic polyether amide can be performed using a solvent such as dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, etc. Requires solvent.
For this reason, in this embodiment, in view of the solvent resistance to the solvent, a dry etching method using a reactive gas is used without using the solvent. As this reactive gas, O₂RIE (reactive ion etching) using a gas or plasma ashing can be used.
[0014]
In dry etching using this reactive gas, the photoresist used for the mask and the thermoplastic polyetheramide are etched at approximately the same rate, so the photoresist film thickness is that of the thermoplastic polyetheramide. By making it more than twice, no problem arises.
After the thermoplastic polyether amide 3 is etched into a predetermined pattern, the photoresist is peeled off to obtain the state shown in FIG.
[0015]
  Next, as shown in FIG. 2C, the supply port 4 is formed by anisotropic etching using the thermoplastic polyetheramide resin film 3 as a mask.
In anisotropic etching, an alkaline etching solution such as KOH, NaOH, or TMAH can be used. However, the concentration of the solution, the processing temperature, the etching rate, and the smoothness of the etched surface are correlated. In this embodiment, TMAH 22 wt% was etched at a processing temperature of 80 ° C. In this case, the etching rate is about 30 to 40 μm / h.
Also, the substrate 1 is etched during the etching.ApplyIf the etching solution touches the surface opposite to the surface and causes a problem, as a protection, apply the above-mentioned thermoplastic polyether amide over the entire surface or do not touch the etching solution using a jig or the like. Measures can be taken.
[0016]
The thermoplastic polyether amide as the resin film 3 used for the etching mask after the completion of the anisotropic etching is removed as necessary. As the removing means, a solvent or a dry etching method can be used similarly to the method used for the pattern formation of the thermoplastic polyether amide described above.
As described above, by using the thermoplastic polyetheramide resin film 3 as an etching resistant mask for anisotropic etching, an ink jet head can be formed at a relatively low cost and with a simple process.
In addition, a well-known thing can be used for the process after the manufacturing process of the inkjet head shown to Fig.2 (a)-(c), Thereby, an inkjet head can be completed, The description is abbreviate | omitted. To do. The head of this embodiment is a so-called side shooter type that ejects ink in a direction perpendicular to the substrate 1.
[0017]
[Example 2]
The second embodiment of the present invention provides a more effective configuration for reducing the number of defects in the etching mask.
That is, as shown in FIGS. 3A to 3C, an etching mask is formed with a two-layer structure of the dielectric layer 2 and the polyetheramide resin layer 3.
Originally, the dielectric film 2 is reliable and generally used as an anti-etching mask for anisotropic etching. However, as described above, the dielectric film 2 is formed over the entire surface of the Si substrate 1 without defects. It is relatively difficult to form. For this reason, in this embodiment, the two-layer structure is used as described above.
[0018]
As shown in FIG. 3A, the dielectric film 2 is made of SiO.₂Alternatively, SiN is formed on the entire surface of the Si substrate 1, and a polyetheramide resin layer 3 is formed thereon as in the first embodiment. A thermoplastic polyether amide is used as the polyether amide resin layer 3 and a necessary pattern is formed in the same manner as in Example 1. Then, the dielectric film 2 is etched using this pattern as a mask. As the etching means for the dielectric film 2, a known method using a mixed solution of hydrofluoric acid and ammonium fluoride or a dry etching method using a reactive gas can be used.
[0019]
In this embodiment, the pattern of the thermoplastic polyether amide functions as an etching mask for both dielectric film etching and anisotropic etching. However, depending on the process, the dielectric layer and the thermoplastic polyether amide may be used. It is also possible to set the pattern formation in an individual process. Such a case is effective when there is a concern of damaging the thermoplastic polyether amide by the etching solution used for the dielectric film.
As described above, it is possible to provide an etching method with good pattern accuracy and yield by using the structure of the organic resin that compensates for defects in the dielectric film and the dielectric film, which is advantageous for the adhesion of the Si substrate and the anisotropic etching solution. it can.
[0020]
FIG. 5 is a schematic perspective view showing an ink jet printing apparatus that can use the ink jet head obtained by this embodiment.
In the inkjet printing apparatus 100, the carriage 101 is slidably engaged with two guide shafts 104 and 105 extending in parallel with each other. Thereby, the carriage 101 can be moved along the guide shafts 104 and 105 by a driving force transmission mechanism (not shown) such as a driving motor and a belt for transmitting the driving force. An ink jet unit 103 having an ink jet head and an ink tank as an ink container for storing ink used in the head is mounted on the carriage 101.
[0021]
The ink jet unit 103 includes a head for discharging ink and a tank as a container for storing ink supplied to the head. That is, the inkjet unit 103 includes four heads that respectively eject four colors of ink of black (Bk), cyan (C), magenta (M), and yellow (Y), and tanks that are provided corresponding to the four heads. Is mounted on the carriage 101. Each head and tank are detachable from each other, and are provided so that only the tank can be exchanged for each individual ink color as necessary when the ink in the tank runs out. Of course, only the head can be replaced as needed. It should be noted that the configuration of attaching and detaching the head and tank is not limited to the above example, and it is needless to say that the head and the tank may be integrally formed.
[0022]
A paper 106 as a print medium is inserted from an insertion port 111 provided at the front end of the apparatus, and finally its conveyance direction is reversed, and is conveyed to the lower part of the moving area of the carriage 101 by the feed roller 109. As a result, printing is performed from the head mounted on the carriage 101 to the print area on the paper 106 supported by the platen 108 as the head moves.
[0023]
As described above, printing is performed on the entire sheet 106 while alternately repeating printing with a width corresponding to the width of the ejection opening array of the head accompanying the movement of the carriage 101 and feeding of the sheet 106. To be discharged.
At the left end of the movable area of the carriage 101, there is provided a recovery system unit 110 that can be opposed to each head on the carriage 101 at the lower part thereof. In addition, it is possible to perform an operation such as sucking ink from the ejection port of each head. The predetermined position at the left end is set as the home position of the head.
On the other hand, an operation unit 107 including a switch and a display element is provided at the right end of the apparatus. The switches here are used when the apparatus power is turned on / off or various print modes are set, and the display element serves to display various states of the apparatus.
[0024]
[Example 3]
In the following, further preferred embodiments to which the method for dry etching of the polyetheramide resin of the present invention is applied will be described.
The polyether amide resin is used as a protective film as an ink resistant layer of the ink jet head, for example, as a protective layer formed on the substrate of the ink jet head including the heat acting portion as shown in FIG. When an opening is formed in a layer by etching, if a residue due to etching exists on the anti-cavitation layer forming the heat acting portion, the foaming becomes unstable or the discharge amount fluctuates, and ink jet recording is performed. The ejection performance of the head is adversely affected. In particular, in recent ink jet recording heads aiming to improve printing quality by flying in the form of minute liquids, even minute residues that have not been considered a problem in the past have become ignorable.
[0025]
In the dry etching method described above, the etching rate is small and the throughput is not so high. However, when the substrate temperature is increased in order to increase the etching rate, there is a problem in that the resist is denatured by the heat at which the substrate temperature has increased, and the resist cannot be removed with a general stripping solution. In particular, in the case of such dry etching, a thin film-like residue that cannot be removed by etching or a removing solution is generated on the etched surface, so that finer processing is required and further improvement in printing quality is required. As a desired etching method for the protective layer of an ink jet head, it is not suitable for use as it is.
On the other hand, according to the dry etching method of the polyether amide resin of this example, that is, the dry etching method in which etching is performed with an etching gas mainly composed of a mixed gas of oxygen and carbon tetrafluoride, the temperature rise of the substrate is suppressed. The etching rate as small as about 1000 Å / min in the case of using conventional oxygen plasma can be greatly improved without generating an etching residue.
[0026]
Next, Example 3 in which such a polyetheramide resin is applied to a dry etching method will be described in detail.
In Example 3, first, HIMAL HL-1200 (manufactured by Hitachi Chemical Co., Ltd.) was applied as a polyether amide with a spinner, pre-dried at 90 ° C. for 30 minutes, and further dried at 250 ° C. as a sample. The etching rate of etching was determined.
The film thickness was measured with an optical film thickness meter.
[0027]
The measurement results of the etching rate are shown in FIGS.
6 to 8 are data performed using an etching apparatus having an RF frequency of 2.46 GHz. FIG. 6 shows the relationship between the gas composition and the etching rate, FIG. 7 shows the relationship between the pressure and the etching rate, and FIG. 8 shows the RF output. And the etching rate.
FIG. 9 shows the relationship between the gas composition and the etching rate when an anode coupling etching apparatus is used at an RF frequency of 13.56 MHz.
CF_FourIt can be seen that the etching rate is remarkably improved by adding.
[0028]
For gas composition, CF_FourAlthough the addition amount of O can be arbitrarily changed, it is O from the viewpoint of a rice cake and a residue.₂It is preferable to add 2% or more with respect to the flow rate. CF_FourRegarding the direction of increasing the amount of addition, the base composition may be etched at the time of overetching, so the gas composition takes into account the base (especially, the base is easily treated with silicon, silicon oxide film, nitride film, etc.). It is necessary to select.
CF_FourIf excessively added, the etching rate becomes lower than that when no additive is added. Therefore, it is preferable to set the oxygen flow rate within 30%. A range of 5% to 15% is particularly preferable. As for the gas pressure, select stable conditions according to the characteristics of the equipment. Generally, it is performed in the range of 10 Pa to 300 Pa.
Appropriate conditions are selected for the gas flow rate and RF power according to the characteristics of the apparatus. Needless to say, an inert gas such as nitrogen can be added to oxygen or carbon tetrafluoride as an etching gas in order to stabilize the plasma or improve the etching rate.
[0029]
Next, patterning was performed using a resist as a mask, and the patterning characteristics were evaluated.
First, HIMAL HL-1200 was applied to a silicon wafer (6 inches) by 2 μm with a spinner and dried under the above conditions, and resist was patterned using OFPR-800 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a resist.
The resist film thickness was 5 μm.
As an etching condition, an etching apparatus having an RF frequency of 2.46 GHz is used, and O 2 is used as an etching gas.₂  1000sccm, CF_Four  Etching was performed at a pressure of 50 Pa and an RF power of 500 W at 100 sccm.
Also, using the same sample, RF frequency 13.56MHz 0.8W / cm²As an etching gas, O₂  100 sccm, CF_Four  Etching was performed at a pressure of 50 Pa and a stage temperature of 50 ° C. with 10 sccm.
[0030]
As a result, no etching residue was generated, the patterning was good, and the resist could be removed without any problem. At this time, the maximum temperature reached by the substrate was 90 ° C. and 80 ° C.
The resist was peeled off by applying a stripping solution 1112A (manufactured by Shipley Co., Ltd.) at room temperature with ultrasonic waves. As for the patterning accuracy, it finished to −2 μm with respect to the resist pattern width, and the variation was as good as about ± 10%.
[0031]
[Example 4]
Conventionally, as a mask for dry etching, a novolak positive photoresist has been used from the viewpoint of dry etching resistance and fine workability. This novolac positive photoresist is used as an etching mask for polyamide resin. Although not sufficient in terms of etching selectivity (etching rate similar to that of polyamide resin), the conventional photolitholine can be used as it is, and the above-mentioned drawbacks are addressed by increasing the film thickness. For example, when etching 2 [mu] m of polyamide, a novolac positive resist having a thickness of about 5 to 8 [mu] m was used. Therefore, the exposure and development time of the photoresist is long, and there is a problem in productivity. On the other hand, according to the etching mask of the silicon-containing photoresist of the embodiment, a high-quality micro droplet inkjet recording head can be produced with high productivity regardless of whether it is a side shooter type or an edge shooter type. It becomes possible.
[0032]
Further, in the method for dry etching of polyetheramide resin of the present invention, means using a silicon-containing photoresist as an etching mask is applied to a dry etching apparatus using a plasma excitation method by batch-type (multi-sheet processing) microwave discharge. By doing so, it becomes possible to remarkably improve the productivity of patterning as compared with the conventional one.
Conventionally, it has been known that when a plurality of processed objects are processed in the same manner by the above-described dry etching apparatus, there is a loading effect in which the etching rate changes depending on the number of processed sheets (processing area). Even when the polyetheramide resin is used for patterning, the peak of the etching rate shifts due to the influence of such loading, and the influence of the loading is almost eliminated when the etching area is 5 inches or less.
Such a tendency is similarly observed when the polyetheramide resin is dry-etched with a mixed gas of oxygen and carbon tetrafluoride.
In FIG. 10, polyether amide resin (HIMAL HL-1200, manufactured by Hitachi Chemical Co., Ltd.) is applied and baked on a 5-inch wafer, and etching is performed using a batch type dry etching apparatus CDE-7-4 (microwave power source) manufactured by Shibaura Seisakusho. It is the result of measuring the rate.
Etching was performed for 1 minute, and the film thickness was measured by an optical method. Etching conditions are CF_FourAnd O₂And the total flow rate is fixed at 900 sccm, CF_FourThe addition amount of was covered. Power and pressure are fixed at 700W and 50Pa. Wafer loading (processing amount per batch) was changed to 0.5 W (wafer), 1 W, 3 W, and 5 W.
As is apparent from FIG. 10, the composition has a peak at a certain composition, and the carbon tetrafluoride is insufficient at the left side of the peak and the rate is reduced, and conversely, the supply of carbon tetrafluoride is excessive at the right side from the peak. Go down. That is, the peak position differs depending on the number of processed sheets.
Therefore, when performing polyetheramide resin etching using a batch-type etching apparatus, a dummy having almost the same form as the processing object is put in and etching is performed in accordance with the number of processed sheets, or the etching gas composition and etching are determined depending on the number of processed sheets. It is necessary to deal with the situation at different times.
However, in the dry etching method of the polyetheramide resin of the present invention, the means using a silicon-containing photoresist as an etching mask is applied to a dry etching apparatus using a plasma excitation method by batch type (multiple processing) microwave discharge. By doing so, it is possible to realize the patterning of the polyetheramide resin at a high throughput without taking the above-described means for reducing the productivity.
[0033]
Hereinafter, Example 4 will be described in more detail.
In Example 4, 2 μm of HIMAL HL-1200 (manufactured by Hitachi Chemical Co., Ltd.) was applied as a polyether amide with a spinner, pre-dried at 90 ° C. for 30 minutes, and further dried at 250 ° C. Further, for example, FH-SP (trade name) manufactured by Fuji Hunt Electronics Technology Co., Ltd. was applied as a Si-containing resist with a 1 μm spinner, and patterning was performed under the following conditions.
▲ 1 ▼ Pre-baking oven 90 ℃ × 20 minutes
(2) Exposure PLA-600F (Canon) 400mj / cm²
(3) Development Positive resist developer NMD-3 manufactured by Tokyo Ohka
Room temperature dip 25 seconds
▲ 4 ▼ Rinse pure water 1 minute
▲ 5 ▼ Drying Rincer dryer
The Si-containing resist is composed of an alkali-soluble silicone polymer as a polymer and a naphthoquinone diazide type as a photosensitive material, and the Si content of the base polymer is about 20%. Basically, the Si-containing photoresist can be processed as it is with a normal novolac positive resist line, and no new equipment is required.
[0034]
Since the conventional novolac positive resist has an etching rate comparable to that of the polyetheramide resin, the film thickness is 5 to 8 μm. Therefore, the exposure time is long, the development time is long, and the productivity is difficult. By using a Si-containing resist, the etching resistance is drastically improved and the coating film thickness is only about 1 μm. Therefore, the exposure time is 1/4 and the development time is 1/5, and the productivity of patterning is remarkably increased. Improved.
[0035]
Next, etching was performed with a dry etching apparatus CDE-7-4 using a microwave manufactured by Shibaura Seisakusho. Etching conditions are as follows.
(1) Gas CF_Four/ O₂= 85sccm / 815sccm
(2) Etching pressure 50Pa
(3) Power 700W (2.45GHz)
▲ 4 ▼ Time 2 minutes
(Loading 5 inch wafers, etching area is 5 inch wafer × 0.3) The film slip after etching is about 0.1 μm, which is a satisfactory level. Since the Si-containing photoresist is hardly etched, consumption of etching species in the resist portion is small, and the etching rate of the polyether amide is improved accordingly. It was possible to process in about 1/3 of the time when using a conventional resist. After etching, the resist was peeled off, and the etched surface was observed with an SEM, but it was satisfactorily etched without generation of speckled minute residues.
[0036]
As in this example, when polyether amide resin is used as a protective layer (when the etching area is small), etching is performed in one wafer processing to four wafer processing / batch under the same conditions as five wafer processing / batch. Could be done. This is because the silicon-containing resist is hardly etched and does not affect the etching characteristics unlike a novolac-based positive resist, so that etching can be performed under the same conditions for processing one to five wafers.
In addition to the above, the Si-containing photoresist includes a negative resist. For example, there is SNR (silicon negative resist) manufactured by Tosoh Corporation.
[0037]
[Example 5]
In Example 5, the dry etching method of Example 4 described above was applied to an inkjet head.
In this example, a protective film as an ink-resistant layer made of a polyetheramide resin layer was formed on a substrate of an inkjet head including a heater portion disposed on the substrate and a heat acting portion formed by a cavitation-resistant layer. . At that time, for example, 2 μm of HIMAL HL-1200 (manufactured by Hitachi Chemical Co., Ltd.) is applied as a polyetheramide resin, patterning is performed by the method of Example 4, and an opening is formed by etching in the protective layer on the heat acting part. did. When this portion was observed with an SEM after etching, no residue was found due to etching on the anti-cavitation layer forming the heat acting portion.
Next, an ink discharge port and an ink supply port with an ink discharge amount of 8 pl were formed, and the foaming state and discharge state of the heater were observed and the printing was checked. There was no abnormality.
[0039]
【The invention's effect】
  As explained above, according to the present invention,,IBy using a polyetheramide resin layer as a mask when etching the substrate constituting the ink jet head, defects such as pinholes generated in the mask can be reduced during mask formation..
MaThe main departureClearlyAccording to this, the patterning of the polyetheramide resin layer can be performed with high throughput and high accuracy, and without causing an etching residue and suppressing an increase in the substrate temperature.,
  Also,A resist pattern that serves as a mask for etching the polyetheramide resin layer is formed using a silicon-containing photoresist.As a result, the generation of fine etching residues can be eliminated, and the productivity of photolithographic processing can be improved.The
  PoWhile making use of the properties of the polyetheramide resin, fine patterning is required.RuNJJTojeIt can be used as a protective layer as an ink-resistant layer of a head, a protective film of a thermal print head, or a protective film of a semiconductor device, and the reliability of these devices can be improved.
[Brief description of the drawings]
FIGS. 1A to 1D are diagrams showing a configuration of an inkjet head according to a first embodiment of the invention, FIG. 1B is a cross-sectional view taken along line AA ′ in FIG. 1A, and FIG. A schematic plan view of the Si substrate portion, (d) is a schematic cross-sectional view of the Si substrate portion.
FIGS. 2A to 2C are schematic views illustrating the manufacturing process of the ink jet head according to the first embodiment of the invention. FIGS.
FIGS. 3A to 3C are schematic views illustrating manufacturing steps of the ink jet head according to the second embodiment of the present invention. FIGS.
FIG. 4 is a schematic cross-sectional view showing an example of anisotropic etching that does not penetrate the substrate.
FIG. 5 is a schematic perspective view illustrating an example of an ink jet printing apparatus that can use the ink jet head manufactured according to the second embodiment of the present invention.
FIG. 6 is a diagram showing the relationship between the etching rate of polyetheramide and the gas composition when using an RF 2.45 GHz etching apparatus according to Example 3 of the present invention.
FIG. 7 is a diagram showing the relationship between the etching rate of polyetheramide and the pressure when an RF 2.45 GHz etching apparatus according to Example 3 of the present invention is used.
FIG. 8 is a graph showing the relationship between the etching rate of polyetheramide and the RF output when the RF 2.45 GHz etching apparatus according to Example 3 of the present invention is used.
FIG. 9 is a graph showing the relationship between the etching rate of polyetheramide and the gas composition when using an RF 13.56 MHz etching apparatus according to Example 3 of the present invention.
FIG. 10: Polyamide amide resin (HIMAL HL-12 manufactured by Hitachi Chemical Co., Ltd.) is applied and baked on a 5-inch wafer, and etching is performed using a batch type dry etching apparatus CDE-7-4 (microwave power source) manufactured by Shibaura Seisakusho. It is a figure which shows the result of having measured the rate.
FIG. 11 is a partial longitudinal sectional view of an ink jet head for explaining a configuration of a protective layer as an ink resistant layer in the present invention.
[Explanation of symbols]
1: Si substrate
2: Dielectric film
3: Organic resin film
4: Through hole (ink supply port) by anisotropic etching
5: Electrothermal conversion element
6: Discharge port
7: Discharge port plate

Claims (6)

A method of manufacturing an inkjet head for discharging ink,
Preparing a silicon substrate provided with an electrothermal conversion element for discharging ink;
A step of the surface to be etched of the substrate providing the etching-resistant mask having a desired opening pattern,
Providing an ink supply port penetrating the substrate by anisotropically etching the substrate through the etching resistant mask using an alkaline solution, and
The step of providing the etching resistant mask includes:
Applying a polyetheramide on the surface of the substrate to form a polyetheramide resin layer;
Forming a resist pattern as a mask for etching the polyetheramide resin layer on the polyetheramide resin layer by a photolithography process;
The opening pattern is formed in the polyetheramide resin layer by dry-etching the polyetheramide resin layer using an etching gas mainly composed of a mixed gas of oxygen and carbon tetrafluoride with the resist pattern as a mask. And a process of
A method of manufacturing an ink jet head, comprising:   2. The ink jet head manufacturing method according to claim 1, wherein a member for forming an ink flow path is formed on the substrate. After forming the opening pattern on the polyether amide resin layer serving as the etching mask, ink jet head manufacturing method according to claim 1 or claim 2, characterized in that the resist pattern is removed. Wherein in the etching of the polyether amide resin layer, ink jet head manufacturing method according to any one of claims 1 to 3, characterized by the use of N- methylpyrrolidone as a solvent. The resist pattern manufacturing method for an inkjet head according to any one of claims 1 to 4, characterized in that it is formed of silicon-containing photoresist. The amount of carbon tetrafluoride, relative flow rate of the oxygen process for manufacturing an ink jet head according to any one of claims 1 to 5, characterized in that from 5% or within 15%.

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