JP2002307684A - Printer, printer head and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of a heating element as compared with the prior art by applying a printer, a printer head and a method for manufacturing the printer head to, e.g. a thermal system ink jet printer. SOLUTION: The heating element 20 is formed of an alloy of tantalum or tungsten and an IVA group metal, or a nitride of the alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, a printer head, and a method for manufacturing a printer head, and can be applied to, for example, a thermal inkjet printer. The present invention relates to tantalum or tungsten.
By forming the heating element from an alloy with a metal belonging to Group IVA or a nitride of this alloy, the reliability of the heating element can be improved as compared with the related art.

[0002]

2. Description of the Related Art In recent years, in the field of image processing and the like, the need for hard copy colorization has been increasing.
For such needs, conventionally, sublimation type thermal transfer method,
Melt heat transfer method, inkjet method, electrophotographic method,
A color hard copy system such as a heat-developed silver salt system has been proposed.

[0003] Among these methods, the ink jet method is a method in which small droplets of a recording liquid (ink) are ejected from nozzles provided in a recording head and adhere to a recording object to form dots. High quality images can be output. This ink-jet method is different from the method of ejecting ink by an electrostatic attraction method,
It is classified into a continuous vibration generation method (piezo method), a thermal method, and the like.

[0004] Among these methods, the thermal method is a method in which bubbles are generated by local heating of the ink, and the ink is ejected from a nozzle serving as a discharge port by the bubbles, and a color image is printed by a simple configuration. be able to.

[0005] The thermal printer is constructed using a so-called printer head, and the printer head is provided with a heating element for heating the ink, a transistor for driving the heating element, and the like.

That is, the heating element is formed by depositing a resistive material such as tantalum, tantalum aluminum, tantalum nitride or the like on a predetermined substrate by a sputtering method widely used in a semiconductor forming process, forming an Al electrode on the upper layer,
It is formed by forming a protective layer such as a silicon nitride film. In the printer head, a cavitation-resistant layer of a tantalum film, an ink liquid chamber, and a nozzle are formed on the protective layer,
Thus, the ink in the ink liquid chamber can be heated by the heat generated by the heating element. Further, the printer head is configured so that power can be supplied to the heating element by a MOS (Metal Oxide Semiconductor) type or a bipolar type transistor, and furthermore, the operation of the transistor can be controlled by a predetermined driving circuit. The ink droplets can be attached to the paper by being driven by a drive circuit.

[0007]

By the way, in the heating element, during printing, a voltage is repeatedly applied in the form of a pulse, and the energization is repeated. In the conventional printer head, the resistance value of the heating element changes due to the repetition of the energization, and eventually, the resistance element may be disconnected, thereby causing a problem of insufficient reliability.

When this point was examined in detail, as shown in FIG. 9, due to poor adhesion between the resistor film constituting the heating element and the base, the resistor film was lifted up from the base by repeated heat generation. It was found that the heating element was disconnected due to the lifting. Also, even if the wire break does not occur, in the part where the resistor film rises from the base, the heat conduction to the base decreases, causing heat to accumulate and cause the resistor film to melt and break down. I understood.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to propose a printer, a printer head, and a method of manufacturing a printer head which can improve the reliability of a heating element as compared with the related art. It is.

[0010]

According to the first aspect of the present invention, a heating element is formed by forming a resistor film on a predetermined insulating layer and applying the same to a printer head. The resistor film is made of an alloy of tantalum or tungsten and a metal belonging to the group IVA, or a nitride of the alloy.

According to a second aspect of the present invention, a heating element is formed by forming a resistor film on an insulating layer formed on a semiconductor substrate, which is applied to a printer, and the resistor film is formed of tantalum. Alternatively, it is formed of an alloy of tungsten and a metal belonging to Group IVA, or a nitride of the alloy.

According to a third aspect of the present invention, in the method of manufacturing a printer head, a step of forming a heating element by forming a resistor film of a predetermined resistor material on an insulating layer is provided. In this case, the resistor material is an alloy of tantalum or tungsten and a Group IVA metal, or a nitride of the alloy.

When an alloy of tantalum or tungsten and a metal of the IVA group, or a nitride of the alloy is deposited on a silicon oxide film or the like, the heat of formation of the oxide of the group IVA metal is lower than that of silicon. And small,
An oxide of a Group IVA metal is produced, which enhances the adhesion strength. In addition, such an IVA metal precipitates at the grain boundaries of tantalum or tungsten and reinforces the adhesion strength between the grain boundaries. Thus, according to the configuration of claim 1, claim 2 or claim 3, the peeling of the heating element can be prevented even when thermal stress is repeated due to repeated heat generation, by strengthening the adhesion to the base. Thus, the reliability of the heating element can be improved as compared with the related art. In addition, the reinforcement of the adhesion strength between the grain boundaries can also make it difficult to cut the heating element, and can improve the reliability of the heating element as compared with the related art.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings as appropriate.

(1) Configuration of the Embodiment FIGS. 1 to 5 are cross-sectional views for explaining the steps of manufacturing a printer head according to an embodiment of the present invention. In this manufacturing process (FIG. 1A), after cleaning the P-type silicon substrate 11, a silicon nitride film is deposited. In this manufacturing process, the silicon substrate 11 is processed by a lithography process and a reactive ion etching process, thereby removing a silicon nitride film from a region other than a predetermined region where a transistor is formed. Thus, in this manufacturing process, a silicon nitride film is formed in a region on the silicon substrate 11 where a transistor is to be formed.

In this manufacturing process, a thermal silicon oxide film is formed in a region where the silicon nitride film has been removed by a thermal oxidation process, and an element isolation region (LOCOS) for isolating a transistor by the thermal silicon oxide film. : Loca
l oxidation of silicon) 12 is formed. In this manufacturing process, after the silicon substrate 11 is washed, a gate having a tungsten silicide / polysilicon / thermal oxide film structure is formed in the transistor formation region. Further, the silicon substrate 11 is processed by an ion implantation process and a heat treatment process for forming source / drain regions, thereby forming MOS type switching transistors 14, 15, and the like. Here, the switching transistor 14 is a MOS type driver transistor having a light withstand voltage of 30 [V], and is used for driving the heating element. On the other hand, the transistor 15 is
Transistors that constitute an integrated circuit that controls
It operates with the voltage [V]. This step is
Subsequently, a BPSG (BoroPhosepho Silicate Glass) film 16 is deposited by a CVD (Chemical Vapor Deposition) method to form an interlayer insulating layer.

Subsequently, in this step, a connection hole (contact hole) is formed on the silicon semiconductor diffusion layer (source / drain) by a photolithography step and a reactive ion etching method using a CFx-based gas. Further, the silicon substrate 11 is washed with diluted hydrofluoric acid, and a titanium film having a thickness of 20 [nm] and a titanium nitride barrier metal having a thickness of 50 [nm] are sequentially deposited by a sputtering method. Further, in this step, aluminum having a thickness of 600 [nm] is formed by adding 1 [at%] of silicon. Subsequently, a photolithography step and a dry etching step are performed, whereby a first-layer wiring pattern 18 is formed. Thus, in this step, a logic integrated circuit is formed by connecting the MOS transistors 15 constituting the drive circuit by the wiring pattern 18.

In this step, a silicon oxide film (so-called TEOS) which is an interlayer insulating layer is formed by a CVD method.
19, and a CMP (Chemical Mechanical Polishin)
g) The silicon oxide film 19 is smoothed by the step or the resist etch back method. By these processes, in this step, a transistor for driving the heating element, a logic circuit for driving the transistor, and the like are formed on the silicon substrate 11 which is a semiconductor substrate, and these transistors are connected. .

In this step, as shown in FIG. 1B, after an interlayer insulating layer 19 is formed of silicon oxide,
A resistor film 20 is formed by depositing a predetermined alloy material with a predetermined thickness by a sputtering method. Here, in this step, an alloy of tantalum and titanium which is a IVA metal is applied to the material of the resistor film 20. Specifically, in this step, the silicon substrate 11 is placed in a sputtering apparatus in which an alloy of tantalum and titanium is set as a target, and the resistive film is formed by sputtering in an argon gas atmosphere to a thickness of 100 [nm]. 20 is deposited.
In the resistor film 20 formed in this manner, the content on the IVA group metal side is 10 to 50 by weight ratio.
The content of the group IVA metal in the target is set so as to be [%].

It should be noted that such an alloy of tantalum and titanium is set as a target, and the resistor film 20 made of these alloys is used.
Instead of the above, it is also possible to form the resistor film 20 of these alloys by a co-sputtering method using a target made of tantalum and a target made of titanium. In this case, the sputtering amount of titanium is changed. This makes it possible to change the titanium content in the alloy.

Subsequently, as shown in FIG. 2C, a heating element 21 is formed by removing an excessive resistor film from the resistor film 20 by a photolithography process and a dry etching process. I do.

Subsequently, in this step, as shown in FIG. 2D, silicon nitride is deposited to a predetermined thickness by a CVD method.
This allows the heating element 2 to be removed from the dry etching of the wiring material.
1 is formed. Here, this protective layer 22 is formed with a sufficient film thickness (100 [nm] or more).

In this step, as shown in FIG. 3E, after the lithography step, the protection layer 22 is processed by a dry etching step using plasma mainly composed of CFx-based gas, and the connection is made by a wiring pattern. Except for the portion, the protective layer 22 is locally disposed on the heating element 21.

Subsequently, in this step, as shown in FIG. 3 (F), a contact hole is formed by a photolithography step and a reactive ion etching method using a CFx-based gas. Further, the silicon substrate 11 is washed with diluted hydrofluoric acid, and a titanium film having a thickness of 20 [nm] and a titanium nitride barrier metal having a thickness of 50 [nm] are sequentially deposited by a sputtering method. Further, in this step, a predetermined film thickness of aluminum to which 1 [at%] of silicon is added is deposited by sputtering. Thus, in this step, the wiring material film 24 is formed by connecting to the first-layer wiring pattern by a contact hole and by connecting to the heating element 21 at a portion where the heating element 21 is exposed. I have.

When the wiring material film 24 is formed in this manner, this step is, as shown in FIG. 4G, after the photoresist step, anisotropic dry using plasma mainly containing chlorine-based gas. A second-layer wiring pattern 25 is formed by etching. In this step, a wiring pattern for power supply and a wiring pattern for ground are formed by the wiring pattern 25 of the second layer, and the drive transistor 14
Is connected to the heating element 21.

Subsequently, in this step, as shown in FIG. 4H, a silicon nitride film 27 functioning as an ink protective layer is deposited to a thickness of 300 [nm]. Subsequently, FIG.
As shown in (1), a tantalum film having a thickness of 200 [nm] is deposited by a sputtering method, and the anti-cavitation layer 28 is formed from the tantalum film. Subsequently, in this step, the dry film 29 and the nozzle sheet 30 are sequentially laminated. Here, the dry film 29 is made of, for example, a carbon-based resin, and is formed by curing in a predetermined shape and a predetermined thickness so that the ink liquid chamber and the partition of the ink flow path have a predetermined height. On the other hand, the nozzle sheet 30 is a sheet material processed into a predetermined shape so as to form the nozzle 33 which is a minute ink ejection port on the heating element 21, and is held on the dry film 29 by adhesion. You. Thus, this process is performed by the ink liquid chamber 31 and the ink liquid chamber 3 by the dry film 29 and the nozzle sheet 30.
The nozzle 33 is formed so as to form a flow path for guiding ink to the nozzle 1.

(2) Operation of the Embodiment In the above configuration, in the manufacturing process of the printer head according to the embodiment, the semiconductor substrate 11 is formed by processing the semiconductor substrate 11 and arranging the transistors 14 and 15. Then, an interlayer insulating layer 19, a wiring pattern 18, a heating element 21, a wiring pattern 25, a dry film 29, a nozzle sheet 30, and the like are sequentially laminated on the semiconductor substrate 11 to manufacture a printer head. (FIG. 1 (B) to FIG. 5 (I)).

In manufacturing the heating element 21, in this embodiment, the resistor film 20 is formed on the insulating layer 19 of silicon oxide by sputtering, using an alloy of tantalum and titanium which is a IVA metal. The heating element 21 is formed by patterning the resistor film 20. In the heating element 21 formed in this manner, the group IVA metal oxide has a larger negative value of generated heat than silicon oxide.
A group IVA metal oxide is formed, and the adhesion to the base is sufficiently ensured by the group IVA metal oxide.

That is, FIG. 6 shows a group IVA metal (Ti, Zr,
Hf), group VA metals (V, Nb, Ta) and group VIA metals (Cr, M, W) as shown by comparison with silicon oxide, the group IVA metals (Ti, Zr, Hf) ,
It has a feature that the heat of formation of oxide is smaller than that of silicon.

As a result, as shown in FIG. 7A, when the resistor film 20 is deposited on the insulating layer 19 made of silicon oxide, an oxide of a metal belonging to Group IVA is generated at the interface. As a result, the printer head has a Ti-Si-O
A compound layer is formed, and the resistor film 20 firmly adheres to the silicon oxide. In the printer head according to the present embodiment, the lower layer of the heating element 21 is made of silicon oxide, but the same relationship holds for these metals also for silicon nitride.

If the adhesion can be strengthened in this way, even if the heating elements 21 having different linear expansion coefficients with respect to the base repeatedly increase in temperature due to repeated heat generation, it is possible to prevent the heating elements 21 from floating from the base. As a result, a failure of the heating element 21 and a change in resistance value, which occur when the heating element 21 rises above the base, can be improved, and reliability can be improved.

Further, in such an alloy of tantalum and titanium as a Group IVA metal, as shown in FIG. 8, a Group IVA metal precipitates at the grain boundaries of tantalum, and the deposited IVA metal is deposited.
Grain boundaries are strongly held by the metal. As a result, crack breaks starting from the grain boundaries are suppressed, and the reliability of the heating element 21 can also be improved.

(3) Effects of the Embodiment According to the above configuration, the reliability of the heating element can be improved as compared with the related art by forming the heating element with an alloy of tantalum and titanium which is a metal belonging to the IVA group. Can be improved.

(4) Other Embodiments In the above-described embodiment, the case where the heating element is formed by an alloy of tantalum and titanium which is a metal belonging to the group IVA has been described, but the present invention is not limited to this. Instead, tungsten may be used instead of tantalum, and the same effect as in the above-described embodiment can be obtained by using other metals belonging to the IVA group instead of titanium.

In the above-described embodiment, the case where the heating element is formed by an alloy of tantalum and a metal belonging to the group IVA has been described. However, the present invention is not limited to this, and the heating element is formed by a nitride of these alloys. Can produce the same effect as in the above-described embodiment. In the case where a heating element is made of such a nitride, in the co-sputtering, a mixed atmosphere of nitrogen gas and argon gas is used, and the nitrogen content of the nitride is varied according to the amount of nitrogen gas added. Is also good.

In the above-described embodiment, the case where the present invention is applied to the printer head configured to print by heating the ink locally has been described. However, the present invention is not limited to this. The present invention can be widely applied to various printer heads for printing by driving a heating element, such as a printer head, and to printers using these printer heads.

[0037]

As described above, according to the present invention, by forming a heating element from an alloy of tantalum or tungsten and a metal belonging to the group IVA, or a nitride of this alloy, the heating element can be formed as compared with the prior art. Reliability can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining a manufacturing process of a printer head according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view provided for the continuation of FIG.

FIG. 3 is a cross-sectional view provided for a continuation of FIG. 2;

FIG. 4 is a cross-sectional view provided for a continuation of FIG. 3;

FIG. 5 is a cross-sectional view provided for a continuation of FIG. 4;

FIG. 6 is a characteristic curve diagram showing heat of formation of various metals.

FIG. 7 is a cross-sectional view for explaining a compound formed at an interface between a heating element and a base.

FIG. 8 is a schematic diagram for explaining a grain boundary of tantalum.

FIG. 9 is a plan view for explaining an abnormality of the heating element.

[Explanation of symbols]

1, 11: semiconductor substrate, 19: insulating layer, 20: resistor layer, 21: heating element

Claims (3)

[Claims] 1. A printer head for forming a heating element and a transistor for driving the heating element on a semiconductor substrate, and printing a desired image by heating of the heating element, wherein a resistor film is formed on a predetermined insulating layer. Wherein the heating element is formed, and the resistor film is formed of an alloy of tantalum or tungsten and a metal belonging to IVA group, or a nitride of the alloy. 2. A printer for printing a desired image by heat generated by a heating element disposed in a printer head, wherein the heating element is formed by forming a resistor film on an insulating layer formed on a semiconductor substrate. A printer, wherein the resistor film is formed of an alloy of tantalum or tungsten and a metal belonging to Group IVA, or a nitride of the alloy. 3. A method for manufacturing a printer head, wherein a heating element and a transistor for driving the heating element are formed on a semiconductor substrate, and a desired image is printed by the heat generated by the heating element. Forming a transistor, forming an insulating layer on an upper layer of the transistor, forming a resistor film of a predetermined resistor material on the upper layer of the heating element, Forming a heating element, wherein the resistor material is an alloy of tantalum or tungsten and a metal belonging to the group IVA, or a nitride of the alloy.