JP3173811B2 - Substrate for inkjet recording head and method for manufacturing inkjet recording head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a recording head substrate having an electrothermal transducer and a recording functional element formed on a substrate, and a method of manufacturing a recording head employing the recording head substrate. In particular, the present invention relates to a recording head substrate and a method of manufacturing a recording head employed in an ink jet recording apparatus used in a copier, a facsimile, a word processor, an output printer of a host computer, a video output printer, and the like.

[0002]

2. Description of the Related Art Conventionally, a recording head has a structure in which an electrothermal transducer array is formed on a single crystal silicon substrate, and a driving circuit for the electrothermal transducer is used to drive an electrothermal transducer such as a transistor array outside the silicon substrate. A functional element is arranged, and the connection between the electrothermal conversion element and the transistor array is performed by a flexible cable, wired bonding, or the like.

[0003] The simplification of the structure considered for the above-described head configuration or the reduction of defects occurring in the manufacturing process,
Further, for the purpose of uniformizing the characteristics of each element and improving reproducibility, a recording head provided with an electrothermal conversion element and a functional element on the same substrate as proposed in Japanese Patent Application Laid-Open No. 57-72867 is used. An inkjet recording apparatus having the same is known.

FIG. 24 is a cross-sectional view showing a part of a recording head substrate having the above-described structure. Reference numeral 901 denotes a semiconductor substrate made of single crystal silicon. Reference numeral 902 denotes an N-type semiconductor epitaxial region; 903, a high impurity concentration N-type semiconductor ohmic contact region; 904, a P-type semiconductor base region; 905, a high impurity concentration N-type semiconductor emitter region; 920
Is formed. Reference numeral 906 denotes a silicon oxide layer as a heat storage layer and an interlayer insulating layer; 907, a heating resistance layer; 908, an aluminum (Al) wiring electrode; 909, a silicon oxide layer as a protective layer;
30 are formed. Here, 940 is the heat generating portion.
A top plate and a liquid path are formed on the base 930 to form a recording head.

[0005]

Although the above-described structure is excellent, high-speed driving, energy saving, high integration, which are strongly required in recent years for a recording apparatus, have been proposed.
There is still room for improvement to satisfy cost reduction and high reliability.

First, a highly reliable recording head must be provided at a low price. For that purpose, conventionally, it was necessary to improve the exposed end portion of the heating resistor layer which determines the life of the recording head.

That is, an edge 910 which is a connection end of the wiring electrode 908 shown in FIG. 24 is tapered (inclined).
By forming the edge portion 104 ₁ of the wiring electrode 104 shown in FIG.
It has been found that it is possible to reduce the concentration of the current density at the exposed end of No. 3 and prolong the life of the heat generating portion 110.

Further, as shown in FIG. 25A, for example, by tapering the end of the emitter electrode 201, the step coverage of the interlayer film 206 in a portion 205 A in the vicinity thereof and the taper to the end of the wiring electrode 202. , The step coverage of the protective film 203 in the portion 205B in the vicinity is improved, and the respective film thicknesses can be reduced as long as the heat storage effect is not lost, and the throughput during manufacturing can be increased. .

It has been found that the above-mentioned improvement can be achieved by tapering the end of each electrode. However, there is room for improvement when an interlayer film, a protective film and the like are formed by the CVD method.

For example, as shown in FIG.
At the time of film deposition (growth) by the method, a hill-shaped ridge such as Al called hillock is generated and grows, and the unevenness of the hillock 204 causes, for example, a short circuit between the emitter electrode 201 and the wiring electrode 202, causing a malfunction and lowering the yield. Sometimes.

Therefore, the present inventor has believed that suppressing the growth of hillocks during the film deposition by the CVD method improves the yield of the substrate.

An object of the present invention is to solve the above-mentioned technical problems and to provide a recording head base having a long life and a high reliability and a method of manufacturing the recording head at a low cost and with a high yield. Another object of the present invention is to provide a substrate for a recording head capable of high-speed recording and high-resolution recording and a method of manufacturing the recording head. Another object of the present invention is to provide a substrate for a recording head and a method of manufacturing the recording head, which consume less power and save energy.

[0013]

According to the present invention, there is provided a method of manufacturing a substrate for an ink jet recording head, comprising a plurality of electrothermal transducers for generating thermal energy used for discharging ink, and each of the electrothermal transducers. Driving functional elements to be driven respectively, a plurality of wiring electrodes each of which has a tapered end connected to each of the driving functional elements and each of the electrothermal converting elements and connected to each of the electrothermal converting elements,
In a method for manufacturing a substrate for an inkjet recording head, wherein an insulating film provided on the wiring electrode is formed on a substrate,
After depositing the insulating film material on the wiring electrode at a substrate temperature of 50 to 250 ° C. by a plasma CVD method, the insulating film material is further deposited on the deposited insulating film material at a substrate temperature of 250 to 450 ° C. A deposition step of forming the insulating film by depositing the above material by a plasma CVD method, wherein the connection end face of the wiring electrode is etched back with a mask photoresist by an aqueous solution containing tetramethylammonium hydroxide. The wiring layer is formed in a tapered shape by etching the material layer of the wiring electrode.

[0014]

[0015]

Further, according to the method of manufacturing an ink jet recording head of the present invention, there are provided a plurality of electrothermal transducers for generating thermal energy used for discharging ink, and a driving function for driving each of the electrothermal transducers. An element, a plurality of wiring electrodes each of which connects each of the driving functional elements and each of the electrothermal conversion elements and has a tapered end connected to each of the electrothermal conversion elements, and is provided on the wiring electrode. An ink jet recording head substrate forming step of forming an insulating film to be formed on a substrate, and an ink discharging unit forming step of forming an ink discharging unit having a plurality of discharge ports for discharging ink on the recording head substrate. In the method for manufacturing a recording head, the base forming step includes:
After depositing the insulating film material on the wiring electrode at a substrate temperature of 150 to 250 ° C. by a plasma CVD method, the insulating film material is further deposited on the deposited insulating film material at a substrate temperature of 250 to 450 ° C. A deposition step of forming the insulating film by depositing the above material by a plasma CVD method, wherein the connection end surface of the wiring electrode is etched with an aqueous solution containing tetramethylammonium hydroxide to retreat the mask photoresist. The wiring electrode is formed in a tapered shape by etching a material layer of the wiring electrode.

[0017]

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, but may be any as long as the object of the present invention can be achieved.

FIG. 1 is a schematic sectional view of a recording head substrate manufactured according to the present invention.

A substrate 100 as a substrate for a recording head includes:
A heat generating section 110 as an electrothermal conversion element and a bipolar NPN transistor 120 as a functional element for driving are formed on a P-type silicon substrate 1.

In FIG. 1, 1 is a P-type silicon substrate, 2
Are N-type collector buried regions for forming functional elements, 3
Is a P-type isolation buried region for functional element isolation, 4 is an N-type epitaxial region, 5 is a P-type base region for forming a functional element, and 6 is a P-type isolation buried region for element isolation. , 7 are N-type collector buried regions for forming functional elements, 8 are high-concentration P-type base regions for forming elements, and 9 are high-concentration P-type regions for element isolation.
Type isolation region, 10 is an N-type emitter region for forming a device, 11 is a high-concentration N-type collector region for forming a device, 12 is a collector-base common electrode,
13 is an emitter electrode, and 14 is an isolation electrode. Here, an NPN transistor 120 is formed, and the collector regions of 2, 4, 7, and 11 are the emitter regions 1
0 and the base regions 5 and 8 are formed so as to completely surround them. Each cell is surrounded and electrically isolated by a P-type isolation buried region, a P-type isolation region 7 and a high-concentration P-type isolation region as element isolation regions.

Here, the NPN transistor 120 has the N
Two high-concentration N-type collector regions 11 formed on P-type silicon substrate 1 through N-type collector buried region 2 and N-type collector buried region 2, N-type collector buried region 2 and P-type base region 5 through the high concentration N-type collector region 1
Two high-concentration P-type base regions 8 formed inside 1
And a high-concentration N-type emitter region 10 formed between the high-concentration P-type base region 8 with the N-type collector buried region 2 and the P-type base region 5 interposed therebetween. The collector N-type collector region 11 and the high-concentration P-type base region 8 are
Operates as a diode. Further, adjacent to the NPN transistor 120, the P-type isolation buried regions 3 and P
A type isolation region 6 and a high-concentration P type isolation region 9 are sequentially formed. Further, the heat generating resistance layer 103 is composed of the N-type epitaxial region 4, the heat storage layer 101, and the interlayer film 102 provided integrally with the heat storage layer 101.
Is formed on the P-type silicon substrate 1 through the substrate, and the wiring electrodes 104 formed on the heat generating resistance layer 103 are cut to form two edge portions 104 _1, which are connection end surfaces, respectively. The unit 110 is configured.

The entire surface of the substrate 100 for a recording head is covered with a heat storage layer 101 formed of a thermal oxide film or the like, and the electrodes 12, 13, and 14 of the functional elements are formed of Al or the like. Each of the electrodes 12, 13, and 14 has an angle θ (30 degrees or more and 75 degrees or more) with respect to a normal line, as shown in FIGS. 2 and 3 in an enlarged manner (electrodes 14, an emitter, a collector, a base, and the like are omitted). The following) inclined side surfaces (ends).

In the substrate 100 of this embodiment, a collector / base common electrode 12, an emitter electrode 13, and an isolation electrode 14 are formed on a P-type silicon substrate 1 for a recording head having the above-described driving section (functional element). Covered with a heat storage layer 101 with a normal pressure CVD method,
An interlayer film 102 made of a silicon oxide film or the like is formed by a PCVD method, a sputtering method, or the like. Each electrode 1
Since Al and the like forming the layers 2, 13, and 14 have inclined side surfaces, the step coverage of the interlayer film 102 is extremely excellent. Therefore, the interlayer film 102 is thinner than the conventional one so as not to lose the heat storage effect. Can be formed. Interlayer film 1
02 is partially opened so that the collector / base common electrode 1
2. Emitter electrode 13 and isolation electrode 14
A wiring electrode 104 made of Al or the like for electrically connecting to the substrate and forming an electric wiring on the interlayer film 102 is provided. That is, after partially opening the interlayer film 102,
Heating resistance layer 103 of HfB ₂ or the like by sputtering method
And an electrothermal conversion element composed of a wiring electrode 104 made of Al or the like by a vapor deposition method or a sputtering method. Here, as a material forming the heating resistance layer 103, Ta, ZrB ₂ , Ti-W, Ni-Cr, Ta-A
1, Ta-Si, Ta-Mo, Ta-W, Ta-Cu,
Ta-Ni, Ta-Ni-Al, Ta-Mo-Al, T
a-Mo-Ni, Ta-W-Ni, Ta-Si-Al,
Ta-W-Al-Ni and the like.

FIG. 4 is an enlarged sectional view of the electrothermal transducer, and FIG. 5 is an enlarged plan view of the electrothermal transducer.

The wiring electrode 104 of Al or the like has an edge portion 104 ₁ and a side surface 104 ₂ which are connection end surfaces inclined by 30 degrees or more with respect to a normal line. Further, SiO, SiO ₂ , SiN, S is formed on the heat generating portion 110 of the electrothermal transducer shown in FIG. 1 by a sputtering method or a CVD method.
A protective film 105 such as iON and a protective film 106 such as Ta are provided integrally with the interlayer film 102.

Further, the base 100 is provided with the wiring electrode 10
4 of the edge portion 104 ₁ and both side surfaces ₁₀₄₂ and the shape (see FIG. 5) is a linear taper, the collector-base common electrode 12, the edge portion of the emitter electrode 13 and the isolation electrode 14, both sides The shape of the surface also has a linear taper as shown in FIGS.

[0028] Thus, in the substrate 100, the current flow in the heat generating portion 110, as shown in FIG. 6, is not concentrated to the lower edge portion 104 ₁ of the wiring electrode 104. For example, according to one experimental result, the wiring electrode 104
The edge portion 104 ₁ of 8.2 × 10 ⁷ when the current density edge portion 104 is substantially perpendicular the _first shape in the lower A /
cm ² to 2.6 × 10 ⁷ A / cm ² . As a result, it is possible to prevent the heating resistance layer 23 from being partially cut. Therefore, according to, for example, an experimental result of configuring a recording head using this substrate 100, the durability of the recording head is reduced from 7 × 10 ⁷ pulses to 1 pulse. It could be greatly extended to × 10 ⁹ pulses.

Further, since the step coverage of the first protective film 105 can be extremely improved,
The thickness of the first protective film 105 could be made thinner (for example, from 1.0 μm to 0.6 μm) than when the shape of the edge portion 104 ₁ was substantially vertical. As a result, the heating section 11
0 can be efficiently and rapidly transmitted to the ink, and the first protective film 105
Could be approximately doubled.

Further, the interlayer film 102, the protective film 105, etc.
When forming a film of SiO, SiON, SiN or the like by the CVD method, the lower layer of the film is formed at 150 to 250 ° C. in the initial stage of film growth.
After growing at a low temperature, a method of further growing an upper layer of the film at 250 to 450 ° C. was used. That is, since the layer grown at a low temperature has the effect of suppressing the growth of hillocks, the wiring short-circuit caused by the hillocks described above (see FIG.
5 (B)), and the yield of products could be remarkably improved. In the following, for each electrode other than the wiring electrode, the edge portion (connection end surface) is also described as a side surface.

Next, the basic operation of the functional element (drive unit) having the above configuration will be described. FIG. 7 is a schematic diagram for explaining a method of driving the base 100 shown in FIG.

In this embodiment, as shown in FIGS. 1 and 7, the collector / base common electrode 12 corresponds to the anode electrode of the diode, and the emitter electrode 13 corresponds to the cathode electrode of the diode. That is, by applying a positive potential bias (V _H1 ) to the collector / base common electrode 12, the NPN transistor in the cell (SH 1, SH 2) is turned on, the bias current becomes the collector current and the base current, and the emitter electrode 13 More outflow. Further, as a result of the configuration in which the base and the collector are short-circuited, the rise and fall characteristics of heat of the electrothermal transducers (RH1 and RH2) are improved, so that the film boiling phenomenon occurs, and the controllability of the growth and shrinkage of bubbles accompanying the film boiling phenomenon is improved. This improved the ejection of ink stably. This is because, in an ink jet recording head that uses thermal energy, the characteristics of the transistor and the film boiling characteristics are deeply linked, and the switching characteristics are faster and the start-up characteristics are better because the accumulation of minority carriers in the transistors is smaller. It is thought that it is doing. In addition, there is relatively little parasitic effect, there is no variation between elements, and a stable driving current can be obtained.

In this embodiment, furthermore, by grounding the isolation electrode 14, it is possible to prevent the charge from flowing into another adjacent cell and to prevent the problem of malfunction of other elements. It has become.

In such a semiconductor device, the concentration of the N-type collector buried region 2 is set to 1 × 10 ¹⁸ cm ⁻³ or more, and the concentration of the P-type base region 5 is set to 5 × 10 ^{14 to} 5 × 10 5
It is desirable to set it to ¹⁷ cm ^−3, and furthermore, to minimize the area of the joint surface between the high concentration base region 8 and the electrode. In this way, it is possible to prevent the occurrence of a leakage current from the NPN transistor to the ground via the P-type silicon substrate 1 and the isolation region.

The method of driving the base will be described in more detail.

FIG. 7 shows two semiconductor functional elements (cells).
However, in practice, such functional elements are arranged at equal intervals corresponding to, for example, 128 electro-thermal conversion elements, and are electrically connected in a matrix so as to enable block driving. It is connected. Here, for the sake of simplicity, the driving of the electrothermal transducers RH1 and RH2 as two segments in the same group will be described.

In order to drive the electrothermal transducer RH1, a group is first selected by the switching signal G1, and the electrothermal transducer RH1 is selected by the switching signal S1. Then, the transistor-configured diode cell SH1 is positively biased and supplied with current, and the electrothermal transducer RH1 generates heat. This thermal energy causes a state change in the liquid, generates bubbles, and discharges the liquid from the discharge port.

Similarly, when the electrothermal transducer RH2 is driven, the electrothermal transducer RH2 is selected by the switching signal G1 and the switching signal S2, and the diode cell SH2 is driven to supply a current to the electrothermal transducer. I do.

At this time, the P-type silicon substrate 1 is grounded via the isolation regions 3, 6, 9. By providing the isolation regions 3, 6, 9 of each semiconductor element (cell) in this way, malfunction due to electrical interference between the semiconductor elements is prevented.

As shown in FIG. 8, the substrate 100 thus constructed is connected to a liquid passage 505 communicating with a plurality of discharge ports 500.
Channel member 5 made of photosensitive resin or the like for forming the
01 and a top plate 502 having an ink supply port 503 are attached, and a recording head 5 of an ink jet recording system is mounted.
It can be set to 10. In this case, the ink supply port 50
3 is stored in the internal common liquid chamber 504 and supplied to each liquid path 505, and in that state, the base 100
By driving the heat generating unit 110, ink is ejected from the ejection port 500.

Next, the manufacturing process of the recording head 510 according to this embodiment will be described.

(1) P-type silicon substrate 1 (impurity concentration 1
8000 on the surface of about × 10 ¹² to 1 × 10 ¹⁶ cm ^-3 )
After a silicon oxide film of about Å was formed, the silicon oxide film in the portion where the N-type collector buried region 2 of each cell was formed was removed by a photolithography process. After forming the silicon oxide film, N-type impurities (for example, P, As, etc.)
Is implanted, and the impurity concentration is 1 × 10 ¹⁸ c by thermal diffusion.
An N-type collector buried region 2 having a thickness of m ^-3 or more is formed to a thickness of about 2 to 6 [mu] m so that the sheet resistance is as low as 80 Ω / □ or less. Subsequently, the P-type isolation buried region 3
The silicon oxide film in the region where the silicon oxide film is to be formed is
After forming a silicon oxide film of about the same size, a P-type impurity (for example, B or the like) is ion-implanted and a P-type isolation buried region having an impurity concentration of 1 × 10 ¹⁵ to 1 × 10 ¹⁷ cm ⁻³ or more is formed by thermal diffusion. 3 was formed (FIG. 9).

(2) After removing the silicon oxide film on the entire surface, the N-type epitaxial region 4 (impurity concentration 1 × 10 ¹³⁾
１1 × 10 ¹⁵ cm ⁻³ ) was epitaxially grown to a thickness of about 5 to 20 μm (FIG. 10).

(3) Next, a silicon oxide film of about 1000 ° is formed on the surface of the N-type epitaxial region 4, a resist is applied, patterning is performed, and P is formed only in the portion where the low-concentration P-type base region 5 is to be formed. Type impurities were ion-implanted. After removing the resist, thereby forming a low-concentration P-type base region 5 (impurity concentration ^{1 × 10 14 ~1 × 10 17} cm ^-3 or so) as the thickness 5~10μm by thermal diffusion.

After the step (1), the P-type base region 5
The oxide film can be formed by removing the oxide film and then growing a low-concentration P-type epitaxial layer of about 5 × 10 ^{14 to} 5 × 10 ^{17 by} about 3 to 10 μm.

Thereafter, the silicon oxide film is again removed from the entire surface, and a silicon oxide film of about 8000 ° is further formed. Thereafter, the silicon oxide film in the region where the P-type isolation region 6 is to be formed is removed, and the BSG film is entirely removed. The P-type isolation region 6 (impurity concentration: about 1 × 10 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ ) is deposited by a CVD method, and further, reaches the P-type isolation buried area 3 by thermal diffusion. Was formed to a thickness of about 10 μm. Here, BBr ₃
Can be used as a diffusion source to form the P-type isolation region 6 (FIG. 11).

As described above, when the P-type epitaxial layer is used, a structure that does not require the P-type isolation buried region 3 and the P-type isolation region 6 is also possible. The photolithography process and the high-temperature impurity diffusion process for forming the P-type isolation region 6 and the low-concentration base region 5 can be omitted.

(4) After removing the BSG film, 8000Å
After forming a silicon oxide film of the order of magnitude and removing the silicon oxide film only in the portion where the N-type collector region 7 is to be formed, the collector buried region 5 is formed by N-type solid phase diffusion and phosphorus ion implantation or thermal diffusion. receive and to form a N-type collector region 7 so that the sheet resistance is 10 [Omega / □ or lower resistance (impurity concentration 1 × 10 ¹⁸ ~1 × 10 about ^{20 cm-3)} to. At this time, the thickness of the N-type collector region 7 was about 10 μm. Subsequently, after forming a silicon oxide film of about 12,500 ° and forming the heat storage layer 101 (see FIG. 13), the silicon oxide film in the cell region was selectively removed.

The thermal storage layer 101 is formed by forming an N-type collector region 7, forming a 1000-3000 ° silicon thermal oxide film, and further forming a BPSG (boron and phosphorus) by CVD, PCVD, sputtering or the like. (Silicate glass containing phosphorus), PSG (silicate glass containing phosphorus), SiO ₂ , SiON, SiN, or another film may be formed. Thereafter, a silicon oxide film of about 2000 ° was formed.

Resist patterning was performed, and P-type impurities were implanted only into the portions where the high concentration base region 8 and the high concentration isolation region 9 were to be formed. After removing the resist, the silicon oxide film in the region where the N-type emitter region 10 and the high-concentration N-type collector region 11 are to be formed is removed, a thermal oxide film is formed on the entire surface, and N-type impurities are implanted. The N-type emitter region 10 and the high-concentration N-type collector region 11 were simultaneously formed by diffusion. The thickness of each of the N-type emitter region 10 and the high-concentration N-type collector region 11 is 1.0 μm or less, and the impurity concentration is 1 × 10
^{It was about 18} to 1 × 10 ²⁰ cm ⁻³ (FIG. 12).

(5) Further, after removing the silicon oxide film at the connection portion of the partial electrode, Al or the like was entirely deposited to remove Al or the like other than the partial electrode region. Here, unlike the conventional wet etching, in the method of performing etching while retreating the photoresist, Al was removed to obtain a wiring shape having inclined side surfaces.

As an etching solution, a developing solution conventionally used for patterning a resist, that is, an aqueous solution containing TMAH (tetramethylammonium hydroxide) can be used. That is, the side wall of the wiring is inclined by about 60 degrees with respect to the normal line. A stable shape was obtained (FIG. 13).

(6) Then, an SiO ₂ film serving as an interlayer film 102 having a function as a heat storage layer was formed on the entire surface to a thickness of about 0.6 to 2.0 μm by the PCVD method. 150 ~
After depositing a film at a low temperature of 250 ° C. for about 1000 to 3000 °, the remaining film thickness is grown at 250 to 450 ° C.
Then, the film grown at a low temperature acts to suppress the growth of hillocks when the substrate temperature is raised to 250 to 450 ° C. Here, Table 1 shows the results of a study on the substrate temperature, hillock growth and film quality evaluation in the PCVD method.

In Table 1, in the item of the substrate temperature, 200-35
“0” indicates that the film was deposited at 200 ° C. and then further deposited at 350 ° C.
Each numerical value of 0 indicates that the film was deposited at a constant temperature. In the item of numerical hillock suppression, x was observed when hillock growth was considerably observed, Δ was observed when it was observed slightly, and ○ was observed when it was hardly observed. In addition, in the item of film quality, X was particularly coarse, Δ was slightly coarse, and ○ was dense. Hillocks do not grow much when the film is deposited at 100-250 ° C. That is, the number and size (existing density and height) are both small, and growth is suppressed. However, films deposited and formed at low temperatures
The film quality is relatively “coarse”, which may cause a decrease in the reliability of the substrate and the recording head having this film. Also, 15
If the temperature is lower than 0 ° C., it is difficult to control the temperature due to the structure of the CVD apparatus. Therefore, when the film was deposited at 200 ° C. to a film thickness of 1500 ° and then additionally deposited at 350 ° C. to a film thickness of 8500 °, hillock growth was suppressed and a film having good film quality was obtained. On the other hand, when the film was deposited at 300 ° C. or higher, although the film quality was good, hillocks were considerably observed.

[0055]

[Table 1] Study results Not limited to the two-stage CVD method, the substrate temperature at the initial stage of growth is 150 to 250 ° C., and the substrate temperature at the end of growth is 250 to 4 ° C.
Dividing the furnace temperature in the CVD method into three or more steps so that the temperature becomes 50 ° C., or changing the substrate temperature by continuously changing the furnace temperature is also effective for suppressing hillock growth of Al or the like. is there. FIG. 22 shows that the furnace temperature was 200 to 350.
The time change of the film thickness when the CVD method is performed while continuously changing to ° C. is shown. As shown in FIG. 22, a film thickness exceeding 10,000 ° was obtained 60 minutes after the start of the CVD method.

The interlayer film 102 may be formed by a normal pressure CVD method. Not only SiO ₂ film but also SiON
It may be a film, a SiO film or a SiN film.

Next, in order to establish electrical connection, a part of the interlayer film 102 above the emitter region and the base / collector region was opened by photolithography to form a through hole TH (FIG. 14).

When etching an insulating film such as the interlayer film 102 and the protective film 105, a mixed acid etching solution such as NH ₄ F + CH ₃ COOH + HF is used to penetrate the interface between the resist (photoresist for mask) and the insulating film. By doing so, the etched cross-sectional shape becomes tapered (3
0 ° to 75 ° is preferable). This is excellent in step coverage of each film formed on the interlayer film, and is useful for stabilizing the manufacturing process and improving the yield.

(7) Next, H as the heating resistance layer 103
fB ₂ was deposited to a thickness of about 1000 ° on the interlayer film 102 and on the electrodes 13 and 12 corresponding to the upper portions of the emitter region and the base / collector region for electrical connection through the through hole TH.

(8) On the heating resistance layer 103, a pair of wiring electrodes 104, 104 of the electrothermal transducer, a cathode wiring electrode 104 of a diode, and an anode wiring electrode 109
A layer of Al material as about 5000 ° deposited,
The Al and HfB ₂ (heating resistance layer 103) were patterned to form an electrothermal transducer and other wiring at the same time. Here, the patterning of Al is the same as the above method (FIG. 15).

(9) Thereafter, an SiO ₂ film 105 as a protective layer of the electrothermal conversion element and an insulating layer between the Al wirings was deposited by about 10,000 ° by PCVD or the like. the first,
The film growth is performed at a relatively low temperature (150 to 250 ° C.) to suppress the growth of hillocks as described above. The protective film 105 is made of SiO, S, in addition to the SiO ₂ film.
A film such as iN or SiON may be used.

Thereafter, Ta is applied as a protective layer 106 for cavitation resistance to the upper part of the heat generating portion of the electrothermal converter.
Deposited about 00Å.

(10) The electrothermal conversion element, the Ta and the SiO ₂ film 105 formed as described above were partially removed to form a bonding pad 107 (FIG. 16).

(11) Next, a liquid path wall member for forming the ink discharge section 500 and a top plate 502 are arranged on a base having a semiconductor element, and an ink liquid path is formed in the inside thereof. The head was manufactured (FIG. 17).

For a plurality of recording heads manufactured by changing the angle of the edge portion with respect to the normal line by changing the liquid temperature of the taper etching of the Al wiring electrode as described above, the respective electrothermal transducers are block-driven to perform recording. And an operation test. In the operation test, eight semiconductor diodes were connected to one segment, and a current of 300 mA (total 2.4 A) was applied to each semiconductor diode. However, the other semiconductor diodes did not malfunction and performed good ejection. Was completed. Further, since the recording head has a good heat transfer efficiency, the driving power is only 80% of that of the conventional recording head, and the recording head is excellent in high-frequency response. Furthermore, excellent characteristics were obtained in terms of life and uniformity. In addition, the wiring dimensional accuracy, wiring resistance variation, initial non-defective rate, and endurance test results were examined. Table 2 shows the results. Angle to normal is 30
Good results were obtained when the angle was 75 degrees. However, at angles of 5 degrees and 28 degrees with respect to the normal,
Good judgment results could not be obtained due to the endurance test results, and due to the wiring step accuracy and wiring resistance variation at 80 degrees.

[0066]

[Table 2] Wiring electrodes 104 in the present embodiment, at the same time has an inclined edge portion 104 ₁ with respect to the heat generating resistor layer, the structure having inclined side 104 ₂ even in the longitudinal direction of the wiring electrode 104 is obtained.

However, for the purpose of alleviating the concentration of the current density at the end of the heating layer resistance, the wiring electrode may have a connection end face having an angle of 30 to 75 degrees with respect to the normal line of the heating resistance layer. It is necessary, and it is not an absolute condition that the longitudinal side surface of the wiring is inclined.

According to the method described below, only the connection end face of the wiring electrode has an inclination, and the side face in the longitudinal direction is zero with respect to the normal line.
It is possible to have a structure close to vertical of up to 30 degrees.

The operation will be described with reference to FIGS.

After depositing a layer made of HfB ₂ as the heating resistance layer 103a and an Al material for forming the wiring electrode 104a, the heating resistance layer 103a and the wiring electrode 104a are formed twice by repeating a conventionally known photolithography process. I do. At this time, the wiring electrode 104a may be etched by a conventional wet etching method or a dry etching method by RIE using a Cl-based gas.
With these methods, the longitudinal side surface 104b of the wiring electrode 104a has a substantially vertical angle (FIG. 18). next,
As shown in FIG. 19, a resist 11 is formed by a conventionally known method.
1 (mask photoresist) covers portions other than the heating resistor layer 103a. Then, a method similar to the method of forming the emitter electrode or the like, that is, even if the resist 111 is etched back during the etching operation of the wiring electrode 104a, the resist 111 does not reach both side surfaces of the wiring electrode 104a at the end of the etching operation. Resist 111 is applied to wiring electrode 104
a, and the wiring electrode 104a is etched. In this case, the wiring electrode 104 may be etched by alternately spraying two kinds of alkaline solutions having TMAH as main components and having different liquid temperatures. In this way, a structure having the inclined edge portion 104b only in the connection portion with the heating resistance layer 103 was obtained (FIGS. 20 and 21).

An ink jet recording apparatus capable of performing high-speed recording and high-quality recording by attaching the recording head 510 having the above-described configuration to the recording apparatus main body and applying a signal to the recording head 510 from the apparatus main body. Can be.

Next, an ink jet recording apparatus using the recording head of the present invention will be described with reference to FIG.
FIG. 23 shows an inkjet recording device 7 to which the present invention is applied.
It is an outline perspective view showing an example of 00.

The recording head 510 is mounted on a carriage 720 that engages with a spiral groove 721 of a lead screw 704 that rotates via driving force transmission gears 702 and 703 in conjunction with forward and reverse rotation of a driving motor 701. And
The carriage 720 is driven by the power of the drive motor 701.
At the same time, it is reciprocated along the guide 719 in the directions of arrows a and b. Paper holding plate 705 for recording paper P conveyed onto platen 706 by a recording medium feeding device (not shown)
Presses the recording paper P against the platen 706 in the carriage movement direction.

Reference numerals 707 and 708 denote home position detecting means for confirming the presence of the lever 709 of the carriage 720 in this area and switching the rotation direction of the drive motor 701. Reference numeral 710 denotes a support member that supports a cap member 711 that caps the entire surface of the recording head 510, and 712 denotes a cap member 711.
A suction unit that suctions the inside recovers the recording head 510 through the cap opening 713. Reference numeral 714 denotes a cleaning blade. Reference numeral 715 denotes a moving member that enables the blade to move in the front-rear direction. These members are supported by a main body support plate 716. Cleaning blade 714
It goes without saying that a well-known cleaning blade can be applied to this embodiment instead of this embodiment. 717 is
The lever for starting suction for suction recovery moves with the movement of the cam 718 engaged with the carriage 720, and the driving force from the drive motor 701 is controlled by a known transmission means such as clutch switching. A print control unit for giving a signal to the heat generating unit 110 provided on the recording head 510 and controlling the driving of each mechanism described above is provided on the apparatus main body side (not shown).

In the ink jet recording apparatus 700 having the above-described configuration, the platen 7 is driven by the recording medium feeding apparatus.
The recording head 51 moves on the recording paper P conveyed on
0 performs recording while reciprocating over the entire width of the recording paper P. Since the recording head 510 is manufactured by the method described above, high-precision and high-speed recording is possible. .

In the above description, an example was described in which the substrate was employed in an ink jet recording head.
The substrate according to the present invention can be applied to, for example, a substrate for a thermal head.

The present invention particularly provides an excellent effect in a recording head and a recording apparatus of a type which ejects ink using thermal energy, which is proposed by Canon Inc. among ink jet recording methods.

For the representative configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling to the electrothermal transducer, heat energy is generated in the electrothermal transducer, and the recording head This is effective because it is possible to form a bubble in the liquid (ink) by one-to-one correspondence with the drive signal as a result of film boiling on the heat-acting surface. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble,
Form at least one drop. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. In addition,
U.S. Pat.
By adopting the conditions described in the specification of 313,124,
Further excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat.No. 4,558,333 and U.S. Pat.
The configuration using the specification of Japanese Patent No. 9,600 is also included in the present invention. In addition, JP-A-59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. Japanese Unexamined Patent Publication (Kokai) discloses a configuration corresponding to the discharge section
The present invention is also effective as a configuration based on Japanese Patent Publication No. 138461/59.

Further, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, a combination of a plurality of recording heads as disclosed in the above specification is used. Either a configuration that satisfies the length or a configuration as a single recording head that is integrally formed may be used, but the present invention can more effectively exert the above-described effects.

In addition, the print head is replaceable with a print head of a replaceable chip type, which can be electrically connected to the main body of the apparatus or supplied with ink from the main body of the apparatus, or is integrated with the print head itself. The present invention is also effective when a cartridge-type recording head provided in a fixed manner is used.

It is preferable to add recovery means for the printhead, preliminary auxiliary means, and the like provided as components of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. . Specifically, for the recording head, a capping unit, a cleaning unit, a pressurizing or suctioning unit, a preheating unit using an electrothermal transducer or another heating element or a combination thereof, and a recording unit It is also effective to perform a preliminary ejection mode for performing another ejection in order to perform stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be a single recording head or a combination of plural recording heads. The present invention is also very effective for an apparatus provided with at least one of full colors by color mixture.

In the embodiments of the present invention described above, the ink is described as a liquid. However, the ink is solidified at room temperature or lower, and is softened or liquid at room temperature. Generally, the temperature is controlled within a range of not less than 70 ° C. and not more than 70 ° C., and the temperature is controlled so that the viscosity of the ink is in a stable ejection range. Good. In addition, positively prevent the temperature rise due to thermal energy by allowing the ink to change its state from the solid state to the liquid state as energy, or
In order to prevent evaporation of the ink, ink that solidifies in a standing state is used, and in any case, the ink is liquefied by application of a heat energy according to the recording signal, and the ink is discharged as a liquid ink or reaches a recording medium. The use of inks that liquefy for the first time with thermal energy, such as those that already begin to solidify at that point, is also applicable to the present invention. In such a case, as described in JP-A-54-56847 or JP-A-60-71260, the ink is held as a liquid or solid in a porous sheet recess or through hole, It is good also as a form which opposes an electrothermal transducer. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

[0085]

As described above, according to the present invention, since the connection end surfaces of the electrothermal transducer and the wiring electrode are in contact with each other on the inclined surface, the current concentration at the end of the electrothermal transducer is greatly reduced. I was able to.

Further, since the connection end face of the underlying wiring electrode is inclined, the unevenness of the upper film caused by the wiring electrode can be formed gently, and excellent step coverage can be obtained. Became possible.

Thus, by making the film thinner, the heat conduction efficiency is increased, and a recording head having low power consumption and excellent frequency response can be realized at low cost. In addition, since the current concentration was reduced, the life of the ink jet recording head substrate and the ink jet recording head was extended, and uniform characteristics were obtained.

That is, a highly reliable and highly uniform substrate for an ink jet recording head and an ink jet recording head could be obtained at low cost.

In addition, an ink jet recording head and an ink jet recording apparatus which can achieve high-speed operation, have fast switching characteristics, have improved rising characteristics, and have a small parasitic effect, can apply suitable thermal energy to liquid, and have improved ejection characteristics. Could be provided.

Further, since the insulating film is deposited on the wiring electrodes while changing the substrate temperature from a low temperature to a high temperature, the growth of hillocks can be suppressed.

As a result, the production yield of the ink jet recording head substrate and the ink jet recording head could be improved.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a recording head substrate manufactured according to the present invention.

FIG. 2 is a sectional view of an electrode of a recording head substrate.

FIG. 3 is a plan view of electrodes of a recording head substrate.

FIG. 4 is a cross-sectional view of an electrothermal conversion element portion of a recording head substrate.

FIG. 5 is a plan view of an electrothermal conversion element portion of a printhead base.

FIG. 6 is a diagram showing a current flow in a heating resistor of a substrate manufactured according to an embodiment of the present invention.

FIG. 7 is a schematic diagram for explaining a method of driving a recording head manufactured according to the present invention.

FIG. 8 is a schematic perspective view showing the appearance of a recording head manufactured according to the present invention.

FIG. 9 is a schematic cross-sectional view for explaining an example of the method for manufacturing a recording head according to the present invention.

FIG. 10 is a schematic cross-sectional view for explaining an example of the method for manufacturing a recording head according to the present invention.

FIG. 11 is a schematic cross-sectional view for explaining an example of the method for manufacturing a recording head according to the present invention.

FIG. 12 is a schematic cross-sectional view for explaining an example of the method for manufacturing a recording head according to the present invention.

FIG. 13 is a schematic cross-sectional view for explaining an example of the method for manufacturing a recording head according to the present invention.

FIG. 14 is a schematic cross-sectional view for explaining an example of the method for manufacturing a recording head according to the present invention.

FIG. 15 is a schematic cross-sectional view for explaining an example of the method for manufacturing a recording head according to the present invention.

FIG. 16 is a schematic cross-sectional view for explaining an example of the method for manufacturing a recording head according to the present invention.

FIG. 17 is a schematic cross-sectional view for explaining an example of the method for manufacturing a recording head according to the present invention.

FIG. 18 is a schematic view for explaining another example of the method for manufacturing a recording head according to the present invention.

FIG. 19 is a schematic view for explaining another example of the method of manufacturing a recording head according to the present invention.

FIG. 20 is a schematic diagram for explaining another example of the method for manufacturing a recording head according to the present invention.

FIG. 21 is a schematic view for explaining another example of the method for manufacturing a recording head according to the present invention.

FIG. 22 is a graph showing a time change of a film thickness when a furnace temperature is continuously changed.

FIG. 23 is a schematic perspective view showing an example of an ink jet recording apparatus to which a recording head manufactured according to the present invention can be attached.

FIG. 24 is a cross-sectional view showing a part of a conventional recording head base.

FIG. 25A is a schematic diagram showing a configuration of a base,
(B) is a schematic diagram showing a state in which hillocks have grown on the substrate shown in (A).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 P-type silicon substrate 2 N-type collector buried region 3 P-type isolation buried region 4 N-type epitaxial region 5 P-type base region 6 P-type isolation region 7 N-type collector region 8 High-concentration P-type base region 9 high Concentration P-type isolation region 10 High-concentration N-type emitter region 11 High-concentration N-type collector region 12 Collector / base common electrode 13 Emitter electrode 14 Isolation electrode 100 Recording head 101 Thermal storage layer 102 Interlayer film 103 Heating resistance layer 104 Wiring electrode 105 Protective film 106 Protective film 107 Bonding pad 110 Heat generating part 500 Discharge port 501 Liquid path wall member 502 Top plate 503 Ink supply port 510 Recording head

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsura Fujita 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Shigeyuki Matsumoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (56) References JP-A-57-72867 (JP, A) JP-A-61-154047 (JP, A) JP-A-61-181149 (JP, A) JP-A-3-29325 (JP, A) A) JP-A-1-165126 (JP, A) JP-A-2-258267 (JP, A) JP-A-62-202741 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) B41J 2/05 B41J 2/16 H01L 21/768

Claims (6)

(57) [Claims] A plurality of electrothermal transducers for generating thermal energy used for ejecting ink; a driving functional element for driving each of the electrothermal transducers; Ink jet recording in which a plurality of wiring electrodes each having a tapered end connected to each electrothermal conversion element and connecting to each electrothermal conversion element, and an insulating film provided on the wiring electrode are formed on a substrate. In a method of manufacturing a head substrate, after the insulating film material is deposited on the wiring electrode by a plasma CVD method at a substrate temperature of 150 to 250 ° C., 250 to 450 ° C. is deposited on the deposited insulating film material. A deposition step of forming the insulating film by further depositing a material of the insulating film by a plasma CVD method at a substrate temperature of; The aqueous solution containing ammonium hydroxide, a manufacturing method of an ink jet recording head substrate, characterized in that it is formed into a tapered shape by etching the material layer of the wiring electrodes while the photoresist mask is etched backward. 2. The method according to claim 1, wherein the deposition step is performed at a temperature of 200 ° C. to 350 ° C.
2. The method for manufacturing a substrate for an ink jet recording head according to claim 1, wherein the material of the insulating film is deposited on the wiring electrodes while continuously changing the substrate temperature. 3. The material of the insulating film is SiO ₂ , SiO,
3. The method according to claim 1, wherein the substrate is one of SiN and SiON. 4. A plurality of electrothermal transducers for generating thermal energy used for ejecting ink, a driving functional element for driving each of the electrothermal transducers, and each of the driving functional elements. Ink jet recording in which a plurality of wiring electrodes each having a tapered end connected to each electrothermal conversion element and connecting to each electrothermal conversion element, and an insulating film provided on the wiring electrode are formed on a substrate. A method for manufacturing an ink jet recording head, comprising: a head base forming step; and an ink discharge section forming step of forming an ink discharge section having a plurality of discharge ports for discharging ink on the recording head base. Is obtained by depositing the material of the insulating film on the wiring electrode at a substrate temperature of 150 to 250 ° C. by a plasma CVD method, and then depositing the material of the deposited insulating film. 25 on top of the
A deposition step of forming the insulating film by further depositing a material of the insulating film by a plasma CVD method at a substrate temperature of 0 to 450 ° C., wherein a connection end face of the wiring electrode contains tetramethylammonium hydroxide A method of manufacturing an ink jet recording head, wherein the material layer of the wiring electrode is etched while the photoresist for a mask is etched back with an aqueous solution to form a tapered shape. 5. The method according to claim 1, wherein the deposition step is performed at a temperature of 200 ° C. to 350 ° C.
5. The method for manufacturing an ink jet recording head according to claim 4, wherein the material of the insulating film is deposited on the wiring electrode while continuously changing the substrate temperature. 6. The insulating film is made of SiO ₂ , SiO,
6. The method for manufacturing an ink jet recording head according to claim 4, wherein the method is one of SiN and SiON.