JP2006168169A - Heating resistor film and its production process, ink jet head employing it and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet head having a heating resistor capable of attaining a high quality recording image over a long term by solving the problems of the heating resistor in an ink jet recording head, and to provide its manufacturing process. <P>SOLUTION: The ink jet device employs a heating resistor film composed of a material represented by RuSiON in a heating resistor generating thermal energy being utilized for ejecting ink. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording and printing of characters, symbols, images, etc. by ejecting a functional liquid such as ink onto a recording carrier including paper, plastic sheets, cloth, articles, etc. The present invention relates to a heating resistor film constituting a head, a manufacturing method thereof, an inkjet head using the same, and a manufacturing method thereof.

  An ink jet recording apparatus that records, prints, etc. characters, symbols, images, etc., by ejecting a functional liquid such as ink, etc., to a recording holder including paper, plastic sheets, cloth, articles, etc. It has a feature that high-definition images can be recorded at high speed by ejecting ink as fine droplets at high speed from an ejection port. In particular, an ink jet recording apparatus using an electrothermal converter as an energy generating means used for ejecting ink and ejecting ink by utilizing foaming of ink generated by the thermal energy generated by the electrothermal converter. Has attracted attention in recent years because it is suitable for high-definition images, high-speed recording, miniaturization and colorization of recording heads and apparatuses. (See, eg, US Pat. No. 4,723,129 and US Pat. No. 4,740,796).

  FIG. 1 shows a general configuration of a main part of a substrate of a head used for ink jet recording, and FIG. 2 is for an ink jet recording head cut along a line XX ′ in a portion corresponding to the ink flow path of FIG. 3 is a schematic cross-sectional view of a substrate 2000. FIG.

  The ink jet recording head shown in FIG. 1 is provided with a plurality of discharge ports 1001 on a substrate 1004, and each discharge port 1001 is formed on the substrate 1004 and generates electrothermal energy for discharging ink. An element 1002 is provided in the ink flow path 1003. The electrothermal conversion element 1002 mainly includes a heating resistor 1005, an electrode wiring 1006 for supplying power to the heating resistor 1005, and an insulating film 1007 for protecting them.

  Each ink channel 1003 is formed by joining a top plate integrally formed with a plurality of channel walls 1008 while aligning the relative position with an electrothermal conversion element on the substrate 1004 by means of image processing or the like. Formed with. Each ink flow path 1003 has an end opposite to the ejection port 1001 communicating with a common liquid chamber 1009, and ink supplied from an ink tank (not shown) is stored in the common liquid chamber 1009. The

  The ink supplied to the common liquid chamber 1009 is guided from here to each ink flow path 1003 and is formed and held in the vicinity of the ejection port 1001. At this time, by selectively driving the electrothermal transducer 1002, the ink on the heat acting surface is rapidly heated and boiled using the generated heat energy, and the ink is ejected by the impact force at this time.

  FIG. 2 is a cross-sectional view taken along the line XX ′ of FIG. 1 and shows a heat storage layer composed of a silicon substrate 2001 and a thermal oxide film 2002, and an interlayer film composed of a SiO film, a SiN film, etc., which also serves as a heat storage function 2003, and heat generation. Resistive layer 2004, metal wiring 2005 such as Al, Al-Si, Al-Cu, protective layer 2006 made of SiO film, SiN film, etc., and protective film 2006 from chemical and physical impact caused by heat generation of heat generating resistive layer 2004 A cavitation-resistant film 2007 for protection and a heat acting portion 2008 of a heating resistance layer 2004 are formed.

The following characteristics are required for the heating resistor used in the recording head of these ink jet recording apparatuses.
1. As a heating resistor, it has excellent thermal response and enables ink to be ejected instantly.
2. The resistance value change is small with respect to high-speed and continuous driving, and the ink bubbling state is stable.
3. Excellent heat resistance and thermal stress, long life and high reliability.

  Japanese Patent Application Laid-Open No. 7-125218 discloses a structure in which a TaN film is used as a heating resistor material as a heating resistor layer used in an ink jet head that satisfies these requirements.

The characteristic stability of this TaN film, particularly the resistance change rate during long-term repeated recording, has a strong correlation with the composition of the TaN film, and in particular, a heating resistor composed of tantalum nitride containing TaN 0.8 hex is the long-term repeatable The resistance change rate during recording is small and the ejection stability is excellent.
U.S. Pat. No. 4,723,129 US Pat. No. 4,740,796 JP 7-125218 A

  In recent years, ink jet recording apparatuses are increasingly required to have higher functions such as high image quality and high speed recording.

  Among them, there is a method for improving the image quality by reducing the size of the heater (heating resistor) to reduce the discharge amount per dot and reducing the size of the dots.

  In order to perform high-speed recording, there is a method of increasing the driving frequency by performing driving with shorter pulses than before.

  However, as shown in the relationship explanatory diagram of various driving conditions due to the difference in heater size in FIG. 3A, in order to drive the heater at a high frequency with a configuration in which the heater size is reduced to cope with high image quality. Therefore, it is necessary to increase the sheet resistance value.

  FIG. 3A shows changes in the sheet resistance value and current value of the heating resistor with respect to the driving pulse width when the heater size is large (A) and the heater size is small (B) when the driving voltage is constant. Similarly, FIG. 3B shows the relationship between the sheet resistance value and current value of the heating resistor with respect to the driving voltage when the heater size is large (A) when the driving pulse width is constant and when the heater size is small (B). ).

  As shown in FIGS. 3A and 3B, when the heater size is reduced, the sheet resistance value needs to be increased in order to drive the heater under the same conditions as in the prior art. In addition, the energy value can be reduced by increasing the sheet resistance value and increasing the driving voltage to reduce the current value from the energy relationship, thereby achieving energy saving. In particular, in the case of a configuration in which a plurality of heating resistors are arranged, the effect is increased.

However, as described above, the specific resistance value of the heating resistor such as HfB ₂ , TaN, TaAl, or TaSiN currently used in the ink jet recording head is about 200 to 800 μΩcm. Considering the manufacturing stability of the heating resistor, the stability of the discharge characteristics, and the like, the limit of the thickness of the heating resistor is considered to be about 40 nm. In this case, the sheet resistance value is limited to 200Ω / □. Therefore, when trying to obtain a sheet resistance value higher than that, it becomes difficult to use the above-mentioned materials that are currently used for heating resistors.

When using HfB ₂ , TaN, TaAl, TaSiN, etc., which are currently used for heat generating resistors, heat generating resistors for ink jet recording heads with excellent thermal response by further short pulse drive and high sheet resistance There was a limit to getting.

For this reason, in order to record small ink droplets by reducing the heater size with the increase in definition of the recorded image, HfB ₂ , TaN, TaAl, TaSiN or the like currently used for the heating resistor is used. As long as the heat generating resistor is used, the current value increases, and a problem due to heat generation may occur, and an ink jet head having desired characteristics may not be obtained.

  SUMMARY OF THE INVENTION The main object of the present invention is to solve the problems described above with respect to conventional heating resistors for inkjet recording heads, and to produce an inkjet head having a heating resistor that makes it possible to obtain high-quality recorded images over a long period of time. It is to provide a method.

  Another object of the present invention is to provide an ink jet having a heat generating resistor with stable ejection and a method of manufacturing the same even in a small dot corresponding to high definition of a recorded image and high speed driving corresponding to high speed recording. is there.

In the present invention, the heating resistor has a composition ratio of Ru: 15-30 at%, Si: 35-60 at%, O: 1-10 at%, N: 10-50 at%, and these are 100 at%, or In the ink jet head having a plurality of heating resistors that generate thermal energy used for ejecting ink, the heating resistor has the above-described configuration. An ink jet device characterized by being a heating resistor film.

  In addition, this heating resistor film contains other elements in the extent of traces other than the above atoms within the range in which the desired characteristics are not impaired, that is, the total amount of Ru, Si, O and N is It may be almost 100%. For example, the ratio of the total number of atoms of Ru, Si, O and N (Ru + Si + O + N) to the total number of atoms constituting the material is preferably 99.5 atomic% or more, and more preferably 99.9 atomic% or more.

  That is, the surface and the inside of the thin film may take in the gas in the reaction region, but the effect is not reduced by the ingestion of a small amount of gas such as Ar on the surface or inside. Examples of such impurities include at least one element selected from C, B, Na, and Cl, including Ar.

  Furthermore, the present invention provides an ink discharge port that discharges ink, a plurality of heating resistors that generate thermal energy used to discharge ink, and includes the heating resistor and communicates with the ink discharge port. In a manufacturing method of an ink jet head having an ink flow path, the heating resistor thin film having the above-described structure is formed by a reactive sputtering method using RuSi as a target in a mixed gas atmosphere composed of nitrogen gas, oxygen gas, and argon gas. It is a manufacturing method of the ink jet head characterized by forming.

  In this invention, sheet resistance can be made high by using the thin film of the said structure as a heating resistor. As a result, even if the area is reduced, a high sheet resistance can be obtained, and it can be driven with a short pulse. Further, the heat generating resistor using this material can maintain desired durability even when driven with a short pulse, and can provide a high-quality recorded image over a long period of time. It can be considered that this is largely due to the positive and very small TCR characteristics. Therefore, it can be used not only as an ink jet head but also as a heater material for other thermal heads and the like.

  The ink jet recording head using the heating resistor according to the present invention enables a high resistance heating resistance characteristic corresponding to a reduction in size by reducing the discharge amount per dot by reducing the size of the heating resistor. Even when continuously driven with a short pulse, desired durability is obtained, energy efficiency is high, heat generation is suppressed, energy can be saved, and high-quality recorded images can be provided.

  According to the ink jet recording head manufacturing method of the present invention, it is possible to manufacture a liquid discharge head substrate and a liquid discharge head having the above-described effects.

  A further increase in resistance is required as a heater for an inkjet head. In order to satisfy the need for increasing the resistance of such a heater, it is necessary to apply a new high resistance material.

  When the materials excellent when applied to the conventional ink jet heater are summarized, it can be seen that there are many excellent materials such as TaSiN and CrSiN in which nitrogen is bonded to metal silicide.

From these points of view, as a result of investigating physical properties such as specific resistance of metal silicide, it was predicted that RuSi _1.5 could be used as a heater material for inkjet.

Although the crystal structure of RuSi _1.5 was investigated, it is not clear. The specific resistance is 2400 μΩcm.

Thus, the specific resistance of RuSi _1.5 is large even as a metal silicide alone, and there is a possibility that the specific resistance can be increased by incorporating nitrogen into this material.
The problem is that it is necessary to confirm the durability of the material having a large specific resistance.

  Therefore, a RuSiN film was actually formed by reactive sputtering using a RuSi target and its characteristics were evaluated.

  FIG. 5 shows the result. This represents the correlation between the nitrogen partial pressure and the specific resistance when the RuSiN film is formed by sputtering. As can be seen from this graph, the RuSiN film has a nitrogen partial pressure of 10% and is 3000 μΩcm, and the specific resistance can be increased by further increasing the nitrogen partial pressure. Further, when the TCR of the film formed at a nitrogen partial pressure of 12% was evaluated, it was found that it was as small as about -570 ppm / ° C. From these facts, it was found that the RuSiN film is a film having excellent durability even though the specific resistance is high.

  By the way, we investigated the reproducibility of the characteristics when this RuSiN film was formed under the condition that the nitrogen partial pressure was 6%. As a result, the film formation under the same condition was repeated 30 times, and as a result, the specific resistance value was found to vary by about + 12% at the maximum. As a result of investigating the cause of this phenomenon, it was found that oxygen was detected in the deposited film, and that the variation in the oxygen amount directly became the variation in specific resistance. This is considered that H2O existing in the background when evacuated to vacuum is decomposed and taken into the film. When the background fluctuates, the amount of H2O fluctuates and as a result, the amount of oxygen Variation. Therefore, we have experimentally verified that the amount of oxygen in the film can be controlled by adding about 1.0 to 2.0% oxygen when forming the RuSiN film. Further, it was found that the reproducibility of the specific resistance value when the film was repeatedly formed under the condition of adding oxygen was improved as compared with the case where oxygen was not added, and the degree of variation was improved to around 5%.

  The heating resistor film of the present invention uses a material expressed by RuSiON as a heating resistor. The RuSiON of the present invention can be obtained by adding a nitrogen gas and an oxygen gas to an argon gas using a RuSi target. At this time, it is preferable to add about 1.0 to 2.0% of oxygen gas.

It is preferable that the RuSiON formed by the reactive sputtering method is subsequently heat-treated. By performing the heat treatment, a metal silicide composed of RuSi _1.5 is generated in the RuSiON film, and the durability is further improved because the intermetallic compound is thermally stable and the TCR is small. From these facts, the composition ratio of Ru and Si is preferably close to 1: 1.5 to 2, Ru: 15-30 at%, Si: 35-60 at%, O: 1-10 at%, N: More preferably, it is 10-50 at%.

  Heat treatment is performed by raising the substrate temperature during sputtering to about 400 ° C., slowing the film formation rate, or performing temperature treatment at a high temperature of about 400 ° C. after film formation, or using an RuSiN film as a heating resistor. It is also possible to apply a pulse having the same condition as that of a pulse applied when drawing with using a heating resistor.

  After the RuSiN film is formed, for example, the photoresist is used as a mask to form a desired shape, and then the ReSiN film is exposed between the ends of the pair of electrode layers insulated from each other. A heating resistor element having a predetermined interval is formed.

  Hereinafter, embodiments of the present invention will be described in detail based on a plurality of examples. However, the present invention is not limited only to each example described below, and can be applied to a resistor thin film used for other applications as long as the object of the present invention can be achieved. It is.

  Next, details of the present invention will be described with reference to the drawings.

  An ink jet head according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic plan view of a main part of a substrate of a heat generating part for foaming ink of an inkjet head, and FIG. 2 is a schematic view when cut perpendicularly to the substrate surface along XX ′ of FIG. FIG.

  The heating resistor 2004 in the embodiment of the present invention can be manufactured by various film forming methods, but is generally formed by a magnetron sputtering method using a radio frequency (RF) power source or a direct current (DC) power source as a power source.

  FIG. 4 shows an outline of a sputtering apparatus for forming the heating resistor layer 2004. The sputtering apparatus shown in FIG. 4 includes a target 4001 made of Ru—Si, a flat magnet 4002, a shutter 4011 that controls film formation on a substrate, a substrate holder 4003, a substrate 4004, and a target 4001 and a substrate that are made in advance with a predetermined composition. The power source 4006 is connected to the holder 4003.

Further, the sputtering apparatus illustrated in FIG. 4 includes an external heater 4008 provided to surround the outer peripheral wall of the film formation chamber 4009. The external heater 4008 is used to adjust the atmospheric temperature of the film formation chamber 4009. On the back surface of the substrate holder 4003, an internal heater 4005 for controlling the temperature of the substrate is provided. The temperature control of the substrate 4004 is preferably performed using an external heater 4008 in combination.
The formation of the RuSiON film using the apparatus of FIG. 4 is performed as follows.

First, the film formation chamber 4009 is evacuated to 1 × 10 ⁻⁵ to 1 × 10 ⁻⁶ Pa using an exhaust valve 4007 using an unillustrated exhaust pump. Next, a mixed gas including argon gas, nitrogen gas, and oxygen gas is introduced into the film formation chamber 4009 from the gas introduction port 4010 via a mass flow controller (not shown). At this time, the internal heater 4005 and the external heater 4008 are adjusted so that the substrate temperature and the ambient temperature become predetermined temperatures.

  Next, power is applied from the power source 4006 to the target 4001 to perform sputtering discharge, and the shutter 4011 is adjusted to form a thin film over the substrate 4004.

  The method of forming the heating resistor by the reactive sputtering method using an alloy target made of RuSi has been described.

In this example, the heating resistor film of the present invention was produced under various film forming conditions by using the apparatus shown in FIG.
<Example 1>
The first specific example of the present invention will be described below.

  In FIG. 2, a heat storage layer 2002 having a thickness of 1.8 μm is formed on a silicon substrate 2001 by thermal oxidation as described above, and an SiO 2 film is formed by plasma CVD as an interlayer film 2003 that also serves as a heat storage layer. The film thickness was 1.2 μm. Next, a RuSiON film having a thickness of 40 nm was formed as the heating resistor layer 2004.

The gas flow rate at this time was Ar gas 72 sccm, N ₂ gas 7 sccm, oxygen gas 1 sccm, the power supplied to the target Ru ₂₉ Si ₇₁ was 400 W, and the substrate temperature was 200 ° C.

  Further, an Al—Cu film was formed by a 550 nm sputtering method as the metal wiring 2005 for heating the heat generating resistor layer 2004 by the heat acting portion 2008.

  This was patterned by a photoconductor using a photolithographic method to form a 15 μm × 40 μm thermal action section 2008 from which the Al—Cu layer was removed. As the protective film 2006, a SiN film having a thickness of 1 μm was formed by plasma CVD. In this example, the substrate temperature was kept at 400 ° C. for about 1 hour at this time, which also served as a heat treatment. Finally, a Ta film having a thickness of 200 nm was formed as the anti-cavitation layer 2007 by a sputtering method to obtain a substrate of the present invention. The sheet resistance value of the heating resistor layer having the above shape was 710Ω / □. The TCR characteristic is about -450 ppm / ° C.

The composition ratio of RuSiON was Ru: 22 at%, Si: 42 at%, N: 32 at%, and O: 4 at%.
<Comparative Example 1>
A substrate of Comparative Example 1 was obtained by manufacturing in the same manner as in Example 1 except that the heating resistance layer 2004 was changed as follows. That is, a TaN0.8 film having a film thickness of 100 nm was formed by a reactive sputtering method using a Ta target. At this time, the gas flow rate was set to Ar gas of 64 sccm, N ₂ gas of 16 sccm, nitrogen gas partial pressure of 20%, power to be applied to the Ta target of 350 W, and substrate temperature of 200 ° C. The sheet resistance value of the heating resistance layer was 25Ω / □.
<Evaluation 1>
Using the substrates prepared as Example 1 and Comparative Example 1, the foaming voltage Vth for discharging ink was determined. With respect to this Vth, a driving pulse width of 2 μsec. The current value when driven by was measured.

That is, in Example 1, Vth = 37V and the current value was 28 mA, while in Comparative Example 1, Vth = 9.9V and the current value was 120 mA. From this result, when the substrate of Example 1 of the present invention and the substrate of Comparative Example 1 are compared, the current value is about ¼ that of the Comparative Example. In the actual head form, since there are a plurality of heating resistors to be driven at the same time, it will be understood that the power consumption is much smaller than that of the comparative example, and an energy saving effect is obtained.
Furthermore, the heat generating resistor was driven under the following conditions, and thermal stress durability evaluation by a break pulse was performed.

  The driving conditions for the heating resistor are shown below.

Drive frequency: 15KHz
Drive voltage: foaming voltage × 1.2, drive pulse width: 1 μsec.
As a result, in the comparative example, the fracture occurred at 6.0 × 10 ⁷ pulses, whereas in Example 1, the fracture did not occur until 2.8 × 10 ⁹ pulses. Thus, it can be seen that the substrate of the embodiment of the present invention can sufficiently withstand short pulse driving.
<Example 2>
A substrate 2000 shown in FIG. 2 was obtained by producing the heating resistance layer 2004 in the same manner as in Example 1 except that the heating resistance layer 2004 was changed as follows. That is, the partial pressure of the gas introduced during film formation was changed. An Ar gas of 70.3 sccm, N2 gas of 8.4 sccm, and oxygen gas of 1.3 sccm were introduced and a RuSiON film having a thickness of 40 nm was formed by reactive sputtering. The target input power was 350 W for a Ru ₂₉ Si71 target, and the substrate temperature was 200 ° C. The sheet resistance value of the heating resistor layer was 1100 Ω / □. The TCR characteristic is -590 ppm / ° C.

The composition ratio of RuSiON was Ru: 19 at%, Si: 40 at%, N: 38 at%, and O: 3 at%.
<Evaluation 2>
In the same manner as in Evaluation 1, the substrate produced in Example 2 was evaluated.
As a result, in the substrate of Example 2, Vth = 39V and the current value was 15 mA.
Further, in the heat stress durability evaluation by the rupture pulse, the rupture was not broken up to 1.0 × 10 ⁹ pulses.

Similar to the result of Evaluation 1, Example 2 also has a small current value and an excellent energy saving effect, and is excellent in durability even when short pulse driving is performed.
<Characteristic evaluation for inkjet>
Further, in order to evaluate the characteristics of the substrate for an ink jet recording head as a heating resistor, the apparatus shown in FIG. An ink jet recording head having a RuSiON film was prepared under one different film forming condition, and its characteristics were evaluated.
<Example 3>
As a sample substrate to be evaluated as ink jet characteristics according to this embodiment, a Si substrate or a Si substrate in which a driving IC is already formed is used.

In the case of a Si substrate, a SiO 2 heat storage layer 2002 (FIG. 2) having a film thickness of 1.8 μm is formed by a thermal oxidation method, a sputtering method, a CVD method, or the like. Then, a heat storage layer of SiO ₂ is formed.

Next, an interlayer insulating film 2003 made of SiO ₂ and having a thickness of 1.2 μm was formed by sputtering, CVD, or the like. Next, a heating resistance layer 2004 was formed by a sputtering method using a RuSi target. The power supplied to the target was 100 W, and the gas flow rate was the same as in Example 1 and the substrate temperature was 400 ° C. This is to accelerate the crystallization of the film by very slowing the film formation rate. For this reason, the substrate temperature was set as high as 400 ° C.

  An Al film was formed as the electrode wiring 2005 by a 550 nm sputtering method. Next, a photolithography method was used to form a pattern, and a 20 μm × 30 μm thermal action section 2008 was formed from which the Al film was removed. Next, an insulator having a thickness of 1 μm made of SiN was formed as the protective film 2006 by plasma CVD. Next, a Ta film having a thickness of 230 nm was formed as the anti-cavitation layer 2007 by sputtering, and an ink jet substrate of the present invention as shown in FIG. 1 was prepared by photolithography.

  An SST test was performed using the substrate thus prepared. This SST test includes a drive frequency of 15 KHz and a drive pulse width of 1 μsec. To obtain the foaming start voltage Vth at which ejection is started. Thereafter, while increasing the applied voltage from Vth every 0.05 V, 1 × 105 pulses are applied at a driving frequency of 15 KHz until disconnection, and the break voltage Vb at the time of disconnection is obtained. The ratio between the foaming start voltage Vth and the breaking voltage Vb is referred to as a breaking voltage ratio Kb (= Vb / Vth). It shows that it is excellent in the heat resistance of a heating resistor, so that this rupture voltage ratio Kb is large. As a result of the evaluation, Kb = 1.50 was obtained.

Next, at a drive voltage Vop = 1.3 × Vth, a drive frequency of 15 KHz and a drive pulse width of 1 μsec. When the resistance value R ₀ of the initial heating resistor is applied as a resistance value R after the pulse application, a resistance value change rate (R−R ₀ ) / R _{0 is applied.} (CST test). As a result, a resistance value change rate ΔR / R ₀ = + 3.5% (ΔR = R−R ₀ ) was obtained.
<Example 4>
As the substrate of the sample to be evaluated as the ink jet characteristics according to this embodiment, the Si substrate or the Si substrate in which the driving IC is already formed is used as in the third embodiment.

In the case of a Si substrate, a SiO 2 heat storage layer 2002 (FIG. 2) having a film thickness of 1.8 μm is formed by a thermal oxidation method, a sputtering method, a CVD method, or the like. Then, a heat storage layer of SiO ₂ is formed.

Next, an interlayer insulating film 2003 made of SiO ₂ and having a thickness of 1.2 μm was formed by sputtering, CVD, or the like. Next, a heating resistance layer 2004 was formed by a sputtering method using a RuSi target. The power input to the target was 350 W, and the gas flow rate was the same as in Example 1 and the substrate temperature was 200 ° C.

  An Al—Si film was formed as the electrode wiring 2005 by a 550 nm sputtering method. Next, a photolitho method was used to form a pattern made of a photoconductor, and a 20 μm × 30 μm heat acting portion 2008 was formed by removing the Al—Si film. Next, an insulator having a film thickness of 1 μm made of SiN was formed as the protective film 2006 by plasma CVD. Also in this case, the substrate temperature was kept at 400 ° C. for about 1 hour to double the heat treatment. Next, a Ta film having a thickness of 230 nm was formed as the anti-cavitation layer 2007 by sputtering, and an ink jet substrate of the present invention as shown in FIG. 1 was prepared by photolithography.

An SST test was performed using the substrate thus prepared. This SST test includes a drive frequency of 15 KHz and a drive pulse width of 1 μsec. To obtain the foaming start voltage Vth at which ejection is started. Thereafter, while increasing the applied voltage from Vth every 0.05V, 1 × 10 ⁵ pulses are applied at a driving frequency of 15 KHz until disconnection, and the break voltage Vb at the time of disconnection is obtained. The ratio between the foaming start voltage Vth and the breaking voltage Vb is referred to as a breaking voltage ratio Kb (= Vb / Vth). It shows that it is excellent in the heat resistance of a heating resistor, so that this rupture voltage ratio Kb is large. As a result of the evaluation, Kb = 1.55 was obtained.

Next, at a drive voltage Vop = 1.3 × Vth, a drive frequency of 15 KHz and a drive pulse width of 1 μsec. , 1.0 × 10 ⁹ pulses are applied continuously, and the resistance value R ₀ of the initial heating resistor is set to the resistance value R after the pulse application, and the resistance value change rate (R−R ₀ ) / R ₀ was determined (CST test). As a result, a resistance value change rate ΔR / R ₀ = + 4.1% (ΔR = R−R ₀ ) was obtained.
<Example 5>
A substrate for an ink jet head was produced in the same manner as in Example 4 except that the heating resistance layer 2004 was formed under the conditions as shown in Example 2. Further, using this substrate, an SST test and a CST test were conducted in the same manner as in Example 4. In this case, a driving voltage Vop = 1.4 × Vth, a driving frequency of 15 KHz, a driving pulse of 1 μsec, and a 1.0 × 10 ³ pulse were applied as heat treatment before the durability test.

As a result, Kb = 1.58 was obtained. Next, at a drive voltage Vop = 1.3 × Vth, a drive frequency of 15 KHz and a drive pulse width of 1 μsec. , 1.0 × 10 ⁹ pulses are applied continuously, and the resistance value R ₀ of the initial heating resistor is set to the resistance value R after the pulse application, and the resistance value change rate (R−R ₀ ) / R ₀ was determined (CST test). As a result, a resistance value change rate ΔR / R ₀ = + 4.3% (ΔR = R−R ₀ ) was obtained.

It is a schematic plan view which shows the board | substrate of the inkjet head of this invention. It is sectional drawing of a board | substrate when FIG. 1 is cut | disconnected perpendicularly by the dashed-dotted line of XX. It is a figure explaining the various drive conditions by the difference in heater size. 1 is a film forming apparatus for forming each layer of a substrate for an ink jet recording head of the present invention. It is a graph which shows the correlation with the nitrogen partial pressure and specific resistance of a RuSiN film.

Explanation of symbols

1001 Discharge port 1002 Electrothermal conversion element 1003 Ink flow path 1004 Substrate 1005 Heating resistor 1006 Electrode wiring 1007 Insulating film 1008 Channel wall 1009 Common liquid chamber 2000 Base 2001 Silicon substrate 2002 Heat storage layer 2003 Interlayer film 2004 Heating resistance layer 2005 Metal wiring 2006 Protective layer 2007 Anti-cavitation film 2008 Heat acting part 4001 Target 4002 Flat magnet 4003 Substrate holder 4004 Substrate 4005 Internal heater 4006 Power source 4007 Exhaust pump 4008 External heater 4009 Deposition chamber 4010 Gas inlet 4011 Shutter

Claims (5)

  The composition ratio is Ru: 15-30 at%, Si: 35-60 at%, O: 1-10 at%, N: 10-50 at%, and these are 100 at% or almost 100 at%. Heating resistor film.   An inkjet head having a plurality of heating resistors for generating thermal energy used for ejecting ink, wherein the heating resistor is the heating resistor film according to claim 1. An ink ejection port for ejecting ink; a plurality of heating resistors for generating thermal energy used for ejecting ink; an ink flow path containing the heating resistor and communicating with the ink ejection port; In the manufacturing method of the inkjet head having
3. An ink jet head, wherein the heating resistor thin film according to claim 1 is formed by a reactive sputtering method using RuSi as a target in a mixed gas atmosphere composed of nitrogen gas, oxygen gas, and argon gas. Manufacturing method.   A method for manufacturing an ink-jet head, comprising performing heat treatment after forming the heating resistor film according to claim 3.   The method of manufacturing an ink-jet head, wherein the heat treatment applies an electric pulse equivalent to an electric pulse actually used for the ink-jet head to the heating resistor film.

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