KR930011861B1 - Recording head - Google Patents

Abstract

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Description

Recording head

1A is a schematic cross-sectional view of a conventional semiconductor device.

1B is a drive circuit diagram using a semiconductor device.

1C is a drive circuit diagram showing an example of using a semiconductor device.

FIG. 2A is a schematic cross sectional view of a portion of a semiconductor device used as a recording head according to the first embodiment of the present invention; FIG.

FIG. 2B is a circuit diagram showing a circuit arrangement portion of the recording head according to the second embodiment of the present invention. FIG.

3 is a diagram showing an example of parasitic effects of a semiconductor device.

4A is a schematic perspective view showing a recording head according to the present invention.

4b is a schematic cross sectional view taken along the line E-E 'in FIG. 4a.

5 is a diagram showing a driving operation of the recording head driving method according to the first embodiment of the present invention.

6A to 6F show a recording head manufacturing process according to the first embodiment of the present invention.

FIG. 7A is a schematic sectional view showing a part of a semiconductor device used in a recording head according to the second embodiment of the present invention; FIG.

Fig. 7B is a circuit diagram showing a part of the circuit structure of the recording head according to the second embodiment of the present invention.

8 is an exemplary diagram showing parasitic effects of a semiconductor device.

9 is a schematic sectional view showing the actual structure of a recording head according to a second embodiment of the present invention.

10 is a diagram showing a recording head driving method according to the second embodiment of the present invention.

11A to 11J are schematic cross sectional views showing a recording head manufacturing process according to the second embodiment of the present invention.

12 is a schematic perspective view of an ink jet recording apparatus equipped with a recording head according to the present invention.

FIG. 13 is a layout diagram of a recording head mounted on the apparatus of FIG.

14 is a carriage arrangement of FIG.

The present invention relates to a recording head for use in a copying machine, a facsimile machine, a word processor, an output printer of a host computer terminal, or a video output printer, and more particularly, to a recording head and a recording device in which a global conversion element and a recording element are formed on a common substrate. will be.

Up to now, a semiconductor device is known in which a plurality of semiconductor elements are arranged and operated simultaneously or alone to control the supply of current to each segment to be controlled.

1A shows one example of such a semiconductor device. In the figure, reference numeral 24 denotes an insulating substrate; The member number 25 includes a semiconductor substrate; A reference numeral 26 denotes an anode semiconductor region; Reference numeral 27 denotes a cathode area.

The semiconductor device is characterized in that the individual diodes are arranged at intervals on the insulating substrate and attached to the substrate.

Since this device has the above structure, the degree of freedom of the reference conditions of the diode is large, and an appropriate diode can be widely selected depending on the intended use. In addition, since electrical interference between diodes can be prevented, a high reverse bias voltage can be interrupted by an insulating substrate, a large current can be supplied, a high breakdown voltage, and a semiconductor device capable of withstanding large currents. Is realized.

FIG. 1B shows an example of an electric circuit using the semiconductor device shown in FIG. 1A.

In this circuit, the switch 29 is closed, the positive potential H ₁ is biased, and the switch 30 is closed so that the current is supplied to the segment 28 such as a load resistance, for example. The diode 31 corresponding to the segment to flow is turned on.

At this time, only the desired segment 28 can be operated alone without affecting other segments.

In the recording head, the desired circuit structure is used. Since each segment, such as an isolation conversion element, is connected to each diode, the segment can be operated alone.

However, in the above conventional example, since each semiconductor element is arranged on an insulating substrate, there are the following technical problems.

(1) Since each diode is placed and attached one by one on an insulated substrate, there are many necessary steps and the cost of the semiconductor device is high.

Since each diode is used, there is a large deviation between the characteristics of the diode. In the case of using multiple diodes, the tolerance can be set to a large value in consideration of the overall balance in the design of the system.

③ When bonding is performed to connect the diodes, the space and shape of the diode arrangement must be taken into account, and the spacing to isolate the diodes must be taken into account. Thus, the yield rate per unit area is reduced, which limits the miniaturization of the entire semiconductor device.

In order to solve the above problems (1) to (3), it is preferable to form a separate element on a common substrate disclosed in US Pat. No. 4,429,321 (Matsumodo).

In the case where the transistor is disposed on the semiconductor substrate and the circuit is configured as shown in Fig. 1C, (5) current is concentrated in the diode having a predetermined withstand current amplifier element if there is a change in the current amplifier element of the transistor.

Emission energy generating element provided inside or outside of the liquid passage corresponding to the heat hole or discharge port used for heat radiation transfer recording and heat recording, and the heat passage for discharging ink, the liquid passage connected to the discharge port, and the semiconductor device. When used for a recording head such as an ink jet recording head configured in a functioning electric / thermal conversion element, it is difficult to avoid the expansion and the high cost of the recording head due to the above-mentioned causes, and the total recording apparatus increases in size and price. do.

In particular, in the recording head used in the ink jet recording apparatus, the inventors have found that the structure of the recording head is influenced by heat generated in the semiconductor device in order to use liquid (ink). It has been found through many experiments that the decision must be thoroughly reviewed and determined.

That is, when the head structure is formed on the common semiconductor substrate, the electrothermal converting element and the semiconductor functional element generating thermal energy, the image quality will vary considerably depending on the wiring, the element structure and the driving conditions. Specifically, there will be a great variation in the adhesion of the ink released on the recording paper. Therefore, in order to obtain a high quality ink jet recording, a structure must be shown which limits the fluctuation of dots to at least one.

The present invention has been made in view of the prior art.

It is a first object of the present invention to provide a low cost semiconductor device that can be manufactured relatively easily.

It is a second object of the present invention to provide a semiconductor device having a plurality of elements, in particular, which reduces fluctuations between elements and in which the device is composed of constant elements.

It is a third object of the present invention to provide a small semiconductor device with high integration.

It is a fourth object of the present invention to provide an effective semiconductor device capable of reducing leakage current due to a parasitic PN junction structure.

A fifth object of the present invention is to provide a semiconductor device composed of a plurality of devices in which the influence on the adjacent devices is prevented and the malfunction of the device does not occur.

A sixth object of the present invention is to provide a recording head having excellent emission characteristics and capable of recording high resolution at high speed.

A seventh object of the present invention is to provide a recording head comprising a semiconductor substrate, a transistor element provided on the semiconductor substrate, and an electric / thermal conversion element provided on the semiconductor substrate, as means for solving the above problems, wherein the recording head Has a first wiring electrode with a closed base and a collector of each transistor element, a second wiring electrode connected to a semiconductor substrate, and a third wiring electrode connected to one of the electrodes of the electric / thermal conversion element, and The emitter and the other electrode of the electric / heat conversion element are connected.

The eighth object of the present invention is; Semiconductor substrates; A transistor device provided on the semiconductor substrate; And a recording head composed of an electrical / thermal conversion element provided on the semiconductor substrate, wherein the recording head is connected to the first wiring electrode connected to one of the electrode pairs of the electrical / thermal conversion element and the emitter of the transistor element. And a second wiring electrode, the base and the collector of each transistor element are closed and connected to the other one of the electrode pairs of the electric / thermal conversion element.

According to the present invention, multiple elements can be formed on the substrate of the recording head by the same steps, and high density, high performance, and miniaturization of the recording head can be realized at low cost.

According to yet another embodiment, the collector and the base of the transistor driving the energy generating element are closed and the current concentration is a diode having a predetermined large current amplifying element, even if there is a variation between the current amplifying elements of the transistors forming a plurality of diodes. It does not occur in. Thus, the energy generating element and the semiconductor element are not destroyed.

On the other hand, according to the embodiment, the semiconductor element and the energy generating element can be formed on the same substrate, and the miniaturization of the high density, high performance recording head can be realized. In addition, according to the circuit arrangement of the embodiment, liquid droplets which are always stable and have excellent emission reaction characteristics can be formed at high speed.

In addition, according to the circuit structure of the present invention, always stable liquid droplets are formed with excellent reaction and high speed.

The invention will be explained in detail according to the following drawings. The present invention is not limited to the examples. Any modification to achieve the object of the present invention may be made within the spirit of the present invention.

Example 1

2A is a schematic cross-sectional view showing a functional element used in the recording head of the present invention. In the drawing, reference numeral 1 denotes an N-type silicon substrate; 2 is an epitaxial region constituting an N-type element; 3, a P-type collector buried region forming an element; 4 is an N-type isolation region for the isolation element; 5 is a P-type collector region constituting an element; 6, a P-type isolation region for separating elements; 7 is a high concentration P-type emitter region constituting the device; 8, a high concentration P-type base region constituting the device; 9 is a high concentration P-type isolation region constituting the device; 10 represents an N-type isolation region for separating the elements. Such a functional element biases the electrode 11 in the forward direction (V _HI ) and _{applies a} positive potential bias (V _HI ) to the electrode 11 so that the PNP transistor inside the cell is turned on and the bias current is the collector current and the base current. It is operated to flow to the emitter electrode 113 as a. The recording head is preferably driven using a configuration in which the base and the collector are connected as in the equivalent circuit shown in FIG. 2B. Thus, the fast switching performance required by the recording head is obtained. Improvement in performance is desirable. Parasitic effect is relatively small. Therefore, the variation between devices is small. Thus, stable driving current can be obtained.

In an embodiment, the isolation region is not grounded. In such a semiconductor device, that is, in a semiconductor device in which the isolation region is not grounded, an area including the P-type collector embedding region 3 and the P-type collector region 5 between the collector regions except the high-concentration P-type collector region, and a high-concentration N-type base. It is preferable to reduce the concentration of the region including the N-type epitaxial region 2 and the N-type silicon substrate between the base regions other than the region 8. This is because charges are prevented from entering through the N-type silicon substrate 1 from the P-type collector embedded region 3 to the P-type collector embedded region 3 of another cell.

The reason will be explained in detail with reference to FIG. 3 below. FIG. 3 is a diagram showing an equivalent circuit of the semiconductor device having the parasitic effect shown in FIG. In the figure, R _C represents the internal resistance of the collector region; R _B represents the internal resistance of the base region; R ₃ represents the resistance of the N-type silicon substrate 1.

On the other hand, Tr ₁ corresponds to the PNP transistor formed by the P-type emitter region 7, the N-type epitaxial region 2, and the P-type collector embedded region 3. Tr ₂ corresponds to the NPN transistor formed by the N-type epitaxial region 2, the P-type collector embedded region 3, and the N-type silicon substrate. In addition, Tr ₃ corresponds to the parasitic PNP parasitic transistor formed by the P-type collector buried region 3 and the N-type silicon substrate 1 of the adjacent cell.

In the circuit, when the transistor Tr ₃ is turned on, the transistor of the adjacent cell malfunctions. In order to prevent malfunction, it is desirable to set the values of R _C , R _B and R _S to a large value.

① Tr ₁ is the collector potential

V _C = V _H -V _BE (Tr ₁ ) + R _{CI C}

Is displayed.

On the other hand, Tr ₁ is the base potential

V _B = V _H -V _BE (Tr ₁ )

Is displayed.

Therefore, Tr ₁ decreases the collector-emitter voltage V _BE as much as R _C , so that the operation of Tr ₁ is set to the saturation region. Therefore, when R _C is large, B decreases, and since most of the current from the emitter flows to the base due to the increase of B, current leakage to other cells is reduced.

② There is an effect obtained by increasing the R _B value. Is generated when a current (I _B) occur, the emitter potential of the Tr ₂ is a larger value of R _B, which makes it difficult that Tr _2-one.

(3) When the current flows into Tr ₂ , the potential drop increases because the value of R _S is large, so that the Tr ₃ potential rises and it becomes difficult to turn on Tr ₃ .

As described above, in order to prevent malfunction of adjacent cells, it is preferable to set the values of each of R _C , R _B and R _S large. The values of R _C , R _B and R _S can be set to a large value, for example, by reducing the concentration of the collector region, the base region and the N-type silicon substrate 1. In the examples, the impurity concentration was set to a value in the range of 1 × 10 ¹⁵ to 1 × 10 ⁻¹⁷ cm ⁻³ .

4A is a perspective view showing an ink jet recording head according to the present invention. Reference numeral 500 denotes a discharge portion for discharging ink, and 501 denotes a liquid passage wall member leading to the jetting portion 500 forming a liquid passage. The liquid passage wall member 501 is formed by a photosensitive resin or the like. Reference numeral 502 denotes an upper plate formed of glass, resin, or the like, and 503 denotes a supply portion of a liquid.

FIG. 4B is a schematic cross sectional view shown along the line E-E 'in FIG. 4A showing the ink jet recording head having the driving portion of the semiconductor element described above. The liquid passage wall member 501 and the upper plate 502 have not been described in detail.

5 is a diagram for explaining a method of driving the recording head shown in FIGS. 4A and 4B.

In the recording head 100 of the embodiment as shown in FIG. 4B, the SiO ₂ film 101 having the drive portion is formed by thermal oxidation formed on a substrate. The electrical / thermal conversion element formed by the electrode 104 made of Al or the heat generating resistive layer 103 made of HfB _{2 or the} like is supplied onto the heat storage layer 102 including the SiO ₂ film formed by the spraying process on the oxide film. do.

Moreover, the heat insulating protective film 105 made of SiO _{2 or the} like and the semi-cavitation protective film 106 made of Ta or the like formed by the spraying process are supplied on and over the heat generating unit 110 of the electric / heat conversion element.

On the other hand, the SiO ₂ film formed by spraying and forming the heat storage layer 102 is completely formed of a heat insulating film between the wirings 201 and 203 of the driving unit. Also for the protective layer 105, the film is formed completely similarly to the inner layer heat insulating film between the wirings 201 and 202.

The protective layer 107 made of glass material such as photosensitive polyimide is supplied as a short film having excellent recording liquid resistance on the wiring 202 of the upper plate at the driving portion.

Apart from the structure shown in FIG. 4A, the recording head can also be assembled in a method such as a groove, an upper plate using an orifice plate, such as not shown to form a liquid passage with the jetting portion. To be arranged. As described above, the recording head may also be assembled in such a manner that liquid is injected in a direction generating a heat generating surface, for example, in a direction transverse to the vertical direction, and the liquid generating surface of the electric / heat converting element as shown in FIG. 4A. It is different from the type that is sprayed in the direction almost parallel to.

The method of driving the recording head is now described in detail with reference to FIG. Although only two cells are shown in FIG. 5, as described above, an appropriate number of 128 cells are arranged and electrically connected in an M × N matrix.

The manner of driving the electrothermal resistance elements RH ₁ and RH ₂ as two elements between the N elements in the group between the M groups will now be described.

First, in order to drive the electrothermal conversion element RH ₁ , the preferred group is selected, for example, by the switch G ₁ in the device body part and the electrothermal conversion element RH ₁ of the recording head is switched by the switch S ₁ in the device body part. ) Is selected. Thus, diode cell SH ₁ using the transistor structure is first biased, current is supplied, and electrothermal converting element RH ₁ generates heat. Such thermal energy causes a liquid phase change, so that a film boiling effect is generated, bubbles are generated, and the liquid is injected from the injection portion.

In the method similar to the above, even when driving the electrothermal conversion element (RH ₂ ), the switch (G ₁ ) and S ₂ of the body portion is selectively turned on, the diode cell (SH ₂ ) of the recording head is driven, the current Is supplied to the electrothermal conversion element (RH ₂ ).

Nevertheless, a method of manufacturing a semiconductor device according to another embodiment will be described with reference to FIG. 6.

(1) A silicon oxide film having a thickness of 5000 to 2000 GPa is formed by thermal oxidation on the surface of an N-type substrate 1 having an impurity concentration of about 1 × 10 ¹² to 1 × 10 ¹⁶ cm ^-3 .

(2) The silicon oxide film forming the N-type isolation buried region 4 is wet removed.

③ In order to cope with loss by ion implantation, silicon oxide film is formed until it is about 100 to 3000Å. Impurities such as phosphorus and arsenic are ion implanted into the N-type structure. The N type isolation buried region 4 is formed by thermal active acid (thickness: 5 to 20 mu m, impurity concentration: 1 x 10 ^{15 to} 1 x 10 ^-17 cm ^-3 ).

(4) Next, the oxide film in the region forming the P-type collector embedding region 3 is removed. P-type impurities such as boron are ion implanted through an oxide film about 100 to 3000 에서 thick. The P-type collector buried region 3 is formed by thermal diffusion. At this time, the sheet resistance is set to 1KΩ / □ or more. The film thickness is set to a value in the range of 10 to 20 mu m. The impurity concentration is set as small as 1 × 10 ⁻¹⁵ cm ⁻³ (the above process corresponds to FIG. 6a).

⑤ The oxide film on the surface of the filler is removed. The N-type epitaxial silicon region 2 with an impurity concentration of 1 × 10 ¹² to 1 × 10 ⁻¹⁶ cm ⁻³ and a thickness of about 5 to 20 μm are grown by lamination growth.

(6) Thus, a silicon oxide film of about 1000 to 10000 microns thick is formed on the epitaxial region surface. The oxide film in the region forming the P-type collector region 5 is wet removed. P-type impurities are ion implanted through the newly formed silicon oxide film having a thickness of about 100 to 3000 microns. The P-type collector region 5 is formed by thermal diffusion to form a P-type collector embedding region having an impurity concentration (film thickness: 5 to 10 mu m) of about 1 x 10 ^-17 cm ²³ . At this time, the sheet resistance is set at 1 KΩ / □ or more.

⑦ The region where the N-type isolation region 6 is formed is removed by wet. Phosphorus-containing glass (PSG) films are formed on the entire surface. An N-type isolation region 6 having an impurity concentration of about 1 × 10 ¹⁴ to 1 × 100 ⁻¹⁶ cm ⁻³ is formed by thermal diffusion until it becomes 1 μm or smaller in thickness. (The above process corresponds to Figure 6b.)

(8) Next, the oxide film in the cell region is removed by wet. A silicon film with a thickness of 100 to 3000 mm 3 is formed. Insulation paint is made. P-type impurities are ion implanted only in the P-type emitter region 7 and the high concentration P-type collector region 7. Insulation paint is removed. The regions forming the highly concentrated N-type base region 8 and the highly concentrated N-type isolation region 10 are wet removed. PSG film is formed on the entire surface. P ions are implanted. The P-type emitter region 7, the high-concentration P-type collector region 9, the high-concentration N-type base region 8, and the high-concentration N-type isolation region 10 are formed simultaneously (the thickness of each region is 1 μm or more. Formed small and the impurity concentration is set separately to a value within the range of 1 × 10 ¹⁹ to 1 × 10 ⁻²⁰ cm ⁻³ ).

9. The silicon oxide film is removed at the junction of each electrode. Pure Al is deposited on the entire surface. The remaining Al layer in the remaining region except for the electrode is removed. In order to cause joining between Al and silicon, an alloying process is performed and wiring portions are formed. SiO ₂ film 101 is formed on the region by a spraying process (the process corresponds to Fig. 6c).

A wiring 203 is formed which is electrically connected to the substrate 1 through the insulating region 4. The SiO ₂ film 102, which is used as the heat storage layer and the internal insulating film, is formed on the entire surface by the spraying process until the thickness is about 1.0 mu m (the above process corresponds to FIG. 6d). Next, HfB ₂ having a thickness of 1000 μs is formed into the heat generating resistance layer 103. Al wirings used as the anode electrode wiring 201 and the cathode electrode wiring 202 of the diode and the electrode pairs 104a and 104b of the electric / heat conversion element are stacked on the heat generating resistive layer 103.

Next, Al is an insulating layer between the wires and a protective layer of the electric / heat conversion element, and the SiO ₂ film 105 is formed by spraying. Contact holes are formed. The cathode electrode wiring 202 is formed. As a protective layer against anti-cavitation, a Ta layer about 2000 kW thick is deposited on top of the heat generating portion of the electric / heat conversion element. Furthermore, as a protective layer, the photosensitive polyimide is formed on the SiO ₂ film 105 and the cathode electrode wiring 202 (the above process corresponds to Fig. 6f).

As shown in Fig. 4A, the recording head is manufactured by arranging an upper plate on a substrate having a liquid passing wall member, a semiconductor element formed as described above, and an electric / thermal conversion element.

For the recording head using the semiconductor device according to the embodiment manufactured in the above-described manner, cells having a plurality of elements in FIG. 2B are connected like a matrix so that operation experiments are performed. Even though 300mA (2.4A total) of current flows through each of the eight semiconductor diodes, the other diodes do not malfunction and the droplets are completely ejected.

Although embodiments have been described for the case where a diode is formed of a PNP transistor, similar advantages can also be obtained when using an NPN transistor.

As described above, according to the embodiment, a plurality of semiconductor devices each having a high resistance voltage and excellent in electrical separation performance may be formed on a single substrate. Thus, for example, in a circuit including a semiconductor device connected like a matrix, the number of steps can be reduced since the devices need not be connected one by one from the outside. Thus, the number of failing states can be reduced and high reliability can be ensured.

On the other hand, in some embodiments, the electric / heat conversion element and semiconductor element driven by the semiconductor element may be formed on the same substrate. Therefore, it is possible to obtain a recording head in which the circuit area can be reduced, and the number of steps can be reduced, so that the reliability is high, so that a high resolution recording image can be formed.

Embodiments may be used in semiconductor devices in various applications. For example, the embodiment can also be used as a diode for microcurrent. The embodiment can also be used as a large current diode. As such, as a great advantage of the present invention, it may be the above-mentioned effect that the semiconductor device of the embodiment can be used by a large current because it is excellent with respect to the resistance voltage. Thus, the most typical advantage of the embodiment is that it can be used as a device for large currents.

Furthermore, in the case where the transistor is used as a semiconductor element, the driving voltage is applied to the emitter, the base and the collector are short-circuited, and the electric / thermal conversion element is connected so that the minimum carrier does not enter between the base and the collector, Since the switching speed is high, the generation speed is improved, so the parasitic effect is also reduced, and stable thermal energy to the liquid can be applied, so that good injection characteristics can be obtained.

Example 2

7A shows a drive portion for driving a recording head according to the present invention. In the drawing, reference numeral 71 denotes a P-type silicon substrate: an N-type collector buried region 72 constituting an element; A P-type isolation buried region 73 for separating the elements; An N-type epitaxial region 74; A P-type base region 75 constituting the device; A P-type isolation region 76 for separating the elements; An N-type collector region 77 constituting the element; A high concentration P-type base region 78 constituting the device; A high concentration P-type isolation region 79 for separating the elements; An N-type emitter region 80 constituting the device; A high concentration N-type collector region 81 constituting the element; Collector / base common electrode 82; Emitter electrode 83; And a separator electrode 83. The NPN transistor is formed of an N-type collector buried region 72, a P-type base region 75, and an N-type emitter region 80. The collector region is formed by the regions 72, 77, and 81 to completely surround the emitter region 80, the base regions 75 and 78. On the other hand, the isolation region is formed as an element isolation region by a P-type isolation buried region, a P-type isolation region 77, and a high concentration P-type isolation region. The plurality of cells described above are formed like a matrix. As an embodiment the basic operation of the driving portion having the above configuration will now be described. 7B is a circuit diagram showing the circuit configuration of the semiconductor device according to the embodiment. In an embodiment, for FIG. 7A, the collector / base common electrode 82 corresponds to the anode of the diode and the emitter electrode 83 corresponds to the cathode of the diode. That is, by applying a positive potential bias (V _HI ) to the collector / base common electrode 82, the NPN transistor inside the cell is turned on and the bias currents exit the emitter electrode 83 as collector current and base current. By using the configuration as in the present invention, i.e., by using the configuration shown in FIG. Induced. Moreover, for the embodiment, by connecting the separator electrode 84 to ground, the inflow of charges in other adjacent cells is prevented, thus eliminating the problem of malfunction of other bits.

In the semiconductor device, it is preferable to set the N-type collector embedding region 72 to a value of 1x19 ¹⁹ cm ^-3 or more. On the other hand, it is preferable to set the density | concentration of the base area | region 5 to the value within the range of 1 * 10 <^13> cm <^-3> -1 * 10 <^15> cm <^-3> . It is also desirable to reduce the junction surface area between the highly concentrated base region 78 and the electrode to a minimum. This is because leakage current flowing from the NPN transistor through the P-type silicon substrate 71 and the isolation regions 73, 74, and 76 to the ground GND can be prevented.

The reason why such leakage current is prevented will be described below in detail with reference to FIG.

FIG. 8 shows an equivalent circuit of the semiconductor device shown in FIG. 7A.

In FIG. 8, R _d represents the internal resistance of the collector region (N-type collector buried region 72, N-type collector region 77, and high concentration N-type collector region 81, and R _B is the base region (P-type base region). Denotes internal resistances of the 75 and high concentration P-type base regions 78. Tr ₁ is defined by the N-type collector embedding region 72, the P-type base region 75, and the N-type emitter region 80; Tr ₂ indicates a PNP transistor formed by the P-type base region 75, the N-type collector buried region 72, and the P-type silicon substrate 71. That is, Tr 2 ₂ represents a transistor structure that eventually causes leakage current.

In this circuit (i.e., the driver of the write head), when the parasitic transistor Tr ₂ is on, almost all of the bias current leaks to the substrate 71 and flows GND through the collector and emitter of the transistor Tr ₂ . I'm going. In this case, an extremely large bias current is required to obtain the emitter current of transistor Tr ₁ , which reduces efficiency, increases power consumption, and increases the cost of the power supply.

In order to solve this problem, the following measures have been taken.

① sets the base voltage of gekkeum transistor (Tr ₂₎ no work of Tr on the ₂ higher than the emitter voltage.

② In order to reduce the current (leakage current) flowing from Tr _2, and sets the current amplification factor (β ₂₎ of the Tr ₂ to a small value.

Only the countermeasure ① will be described first. In FIG. ₂ , the voltage V _BE (Tr ₂ ) between the base and the emitter of Tr ₂ is used to prevent Tr ₂ from turning on.

Must be satisfied. now,

therefore,

Therefore, for inequality (1) to be satisfied

Is needed.

That is, in order to prevent Tr ₂ from turning on, it is necessary to set the resistance R _B of the base region to a value equal to or greater than β ₁ times the resistance R _C of the collector region. In order to satisfy this condition, in the semiconductor device shown in FIGS. 7A and 7B, the resistance R _C of the collector region must be reduced, for example, by increasing the concentration of the N-type collector buried region 72. . Alternatively, to increase the resistance R _B of the base region, for example, the concentration of the high concentration P-type region 78 is reduced, or the area of the base region 78 is reduced.

The countermeasure ② will now be described.

라 해도, 만일 β₂＜1이면 P형 실리콘기판(71)에의 누설 전류를 억제할 수 있다. 트랜지스터(Tr₂)의 전류 증폭율(β₂)을 작은 값으로 설정하자면 예를들어 Tr₂의 베이스영역(N형 콜렉터 매입영역(2))의 농도를 증가시키는 것으로 충분하다.Even if the conditions of the measures ① are not satisfied, that is,

Even if β ₂ <1, leakage current to the P-type silicon substrate 71 can be suppressed. To set the current amplification ratio β ₂ of the transistor Tr ₂ to a small value, for example, it is sufficient to increase the concentration of the base region (N-type collector buried region 2) of Tr ₂ .

In other words, the use of the method of increasing the concentration of the N-type collector embedding region 72 is effective in the measures 1) and 2).

For this reason, in the embodiment, the impurity concentration of the N-type collector buried region 72 is set to 1 × 10 ¹⁹ cm ⁻³ or more, and the impurity concentration of the P-type base region 5 is 1 × 10 ¹³ cm ⁻³ or more. It was set to the value in the range of 1x10 ¹⁵ cm ^-3 . 4A is a schematic perspective view showing the ink jet recording head according to the embodiment.

FIG. 9 is a schematic sectional view of the ink jet recording head having the above-mentioned driving portion of the semiconductor element, taken along the line E-E 'of FIG. 4A.

FIG. 10 is a schematic view for explaining a method of driving the recording head of FIG.

In the recording head 1100 of the embodiment, a SiO ₂ film 1101 having the above functional elements and formed by thermal oxidation is formed on a substrate.

The electrothermal conversion element constituted by the heat generating resistive layer 1103 made of HfB _{2 or the} like and the electrode 1104 made of Al or the like is a heat storage layer made of a SiO ₂ film or the like formed by a sputtering process. Iii) above 1102. Then, a protective film 1105 made of SiO _{2 or the} like and a protective film 1106 made of Ta or the like are formed by a sputtering process and provided on the heat generating portion 1110 of the all-electric converter.

The SiO ₂ film forming one of the two heat storage layers 1102 is an interlayer insulating film 1102 between the wirings 82, 83, 84, the wiring 1104 of the electrothermal converting element, the second layer wiring of the driving unit, and the lower wiring. It is formed integrally with

Similarly for the protective layer 1105, the film is formed integrally with the interlayer insulating film 1105 ′ between the second wiring 1104 and the upper layer wiring 1111.

A protective layer 1107 made of an organic material such as photosensitive polyamide is provided as an insulating film having excellent recording liquid resistance on the wiring 1111 at the top of the drive section.

Similarly to the first embodiment, according to this embodiment, a recording head is not shown but a grooved top plate, orifice plate, etc. are arranged to form a passage and a discharge hole of a liquid. It may also be configured as. As described above, unlike the manner in which the liquid is discharged in a direction substantially parallel to the heat generating surface of the electrothermal converting element as shown in FIG. 4A, the recording head is constructed in such a manner that the liquid is discharged in the direction crossing the heat generating surface. You can do it.

The driving method of the recording head will now be described in detail. Although only two cells are shown in FIG. 10, an appropriate number of elements, for example 128, are arranged as previously described and electrically connected as in an M × N matrix.

The method of driving the electrothermal resistance elements RH ₁ and RH ₂ as two of the N segments in one of the M groups will now be described.

First, a desired group is selected by the switch G ₁ in the apparatus main body to drive the electrothermal conversion element RH ₁ , and for example, the switch S ₁ in the apparatus main body is selected. ₁ ). Therefore, the diode cell RH ₁ having the transistor configuration is biased in the forward direction, current is supplied, and the heat transfer element RH ₁ of the write head generates heat. This thermal energy causes a change in the state of the liquid, whereby a film boiling effect occurs, bubbles are generated, and the liquid is released from the discharge hole.

Similarly, in the case of driving the electrothermal converting element RH ₂ , for example, if the switches G ₁ and S ₂ in the device body are selectively turned on, the diode cell RH ₂ in the recording head is selectively turned on. Is driven, and a current is supplied to the electrothermal converting element RH ₂ .

If a P-type semiconductor substrate is used as in the present invention, the isolation electrode 84 is held at ground potential, thereby keeping the substrate at ground potential through the isolation regions 73, 76, 79. Therefore, each cell is separated.

This structure also has the following excellent effects. When this structure is used for the recording head, the substrate 71 itself is partially exposed to the outside or through the constituent members of the conductive body. Thus, the operator may touch the substrate 71.

As shown in FIG. 4A, when a part of the substrate 71 is positioned near the emission orifice, ink and paper dust may adhere to each other. In view of this, when a P-type substrate is used and maintained at ground potential, undesirable electrostatic effects are prevented, whereby deterioration of ink and adhesion of foreign matter such as paper dust are completely prevented.

In addition, even if the operator touches the substrate, the substrate has a ground potential and thus does not harm the operator. It is possible to simultaneously obtain or satisfy the electric element isolation function and the electrostatic shielding function that the recording head should have.

The manufacturing process of the recording head according to the embodiment will now be described.

(1) A silicon oxide film having a thickness of 5000 to 20000 kPa was formed on the surface of the P-type silicon substrate 71 having an impurity concentration of about 1x10 ¹² cm ^-3 to 1x10 ¹⁶ cm ^-3 .

The silicon oxide film of the portion for forming the collector buried region 702 of each cell was removed by a photolithography process.

As a countermeasure to prevent damage during ion implantation, a silicon oxide film was formed until it became about 100 to 3000 mm thick. N-type impurities such as P and AS were ion implanted. An N-type collector buried region 72 having an impurity concentration of 1 × 10 ¹⁹ cm ^-3 or more was formed by thermal diffusion until it became 10 to 20 mu m thick. The area resistance at this time was set to a low value of 30 mW / square or less.

Thereafter, the oxide film in the region for forming the P-type isolation buried region 709 was removed. An oxide film of about 100 to 3000 microns thick was formed. P-type impurities such as B were ion-implanted. A P-type isolation buried region 73 having an impurity concentration of 1 × 10 ¹⁷ to 1 × 10 ¹⁹ cm ^-3 was formed by thermal diffusion (Fig. 11A).

② The oxide film was removed from the whole surface. An N-type epitaxial region 74 having an impurity concentration of about 1 × 10 ¹² to 1 × 10 ¹⁶ cm ^-3 was epitaxially grown to a thickness of 5 to 20 µm (the process corresponds to FIG. 11b).

(3) Then, a silicon oxide film of about 100 to 300 microns thick is formed on the surface of the N-type epitaxial region.

A resist is coated thereon to form a pattern. The p-type impurity was ion-implanted only in the region for forming the low concentration base region 75. The resist was removed. A low concentration P-type base region 75 having an impurity concentration of 1 × 10 ¹³ to 1 × 10 ¹⁵ cm ^-3 was formed by thermal diffusion from 5 to 10 mu m in thickness.

The oxide film over the entire surface was removed. Then, a silicon oxide film having a thickness of about 1000 to 10000 kPa was formed. The oxide film in the region where the P-type isolation region 76 is to be formed was removed (not shown). The BSG film is deposited on the entire surface using a CVD process. A P-type isolation region 76 having an impurity concentration of 1 × 10 ¹⁸ to 1 × 10 ²⁰ cm ^-3 and a thickness of about 10 μm is further formed by thermal diffusion to reach the P-type isolation buried region 73.

④ The BSG film (not shown) was removed. A silicon oxide film with a thickness of about 1000 to 10000 kPa was formed. And the oxide film of only the area | region to form the N type collector area | region 77 was removed. PSG films were formed, whereby P ⁺ ions were implanted. An N-type base region 77 is formed by thermal diffusion to reach the collector embedding region 75. The area resistance at this time was set to a low value of 10 dB / square or less. On the other hand, the thickness of the N-type collector region 77 was set to about 10 mu m, and the impurity concentration was set to a value of 1 x 10 ¹⁸ to 1 x 10 ²⁰ cm ^-3 .

Thereafter, the oxide film in the cell region was removed. A silicon oxide film having a thickness of 100 to 3000 mm 3 was formed. The resist was patterned. P-type impurities were ion-implanted only in the region where the high concentration base region 78 and the high concentration isolation region 79 were to be formed. The resist was removed. The oxide film in the region where the N-type emitter region 80 and the high concentration N-type collector region 81 were formed was removed. PSG film was formed over the entire surface. N ⁺ ions were implanted. A high concentration P-type base region 78, a high concentration P-type isolation region 79, an N-type emitter region 80, and a high concentration N-type collector region 81 were simultaneously formed by thermal diffusion. The thickness of each region was set to 1.0 mu m or less, and the impurity concentration was set to a value in the range of 1x10 ¹⁹ to 1x10 ²⁰ cm ^-3 (the above process corresponds to Fig. 11d).

(5) And the silicon oxide film in the connection position of each electrode was removed. Contact holes were formed. Pure Al was deposited all over the surface. Al in regions other than the electrode region was removed. In order to increase the bonding performance between Al and silicon, an alloy (clloy) process was performed to form lower wiring portions 82, 83, and 84 (FIG. 11E).

(6) A heat storage layer and a SiO ₂ film 1102 having a thickness of about 1.0 μm serving as an interlayer insulating film were formed on the entire surface by a sputtering process. Through holes were formed by etching for electrical connection between the emitter and the base / collector (FIG. 11f).

Then, HfB ₂ having a thickness of about 1000 mW is attached and patterned as the heat generating resistive layer 1103. Electrode pairs 1104 and 1104 'of the electrothermal converting elements are formed. And Al is attached by sputtering for electrical connection between one electrode 1104 and emitter electrode 83. Then, the desired electrical connection is obtained by etching for patterning each electrode and the intermediate wiring (FIG. 11g).

Next, a silicon oxide film serving as an insulating layer between the protective layer of the electrothermal conversion element and the intermediate wiring and the upper wiring formed thereon is attached by sputtering.

Next, through holes are formed in the silicon oxide film by etching. Again, the upper wiring 1111 connected to the base / collector electrode 82 through the intermediate Al layer is formed by Al deposition and patterning.

Therefore, the isolation wiring is provided in the lower layer. The emitter (cathode) wiring and the wiring of the electrothermal conversion element are provided at intermediate positions.

Base / collector (anode) wiring is disposed at the topmost position. As a result, a three-layer wiring structure in which each layer is connected through two holes (Fig. 11h).

Next, as a protective layer for preventing cavitation, a Ta layer 1106 of about 2000 kPa is formed on the top of the electrothermal transducer. On the other part, a photosensitive polyamide layer 1107 made of an organic material is formed as a protective layer (Fig. 11i).

The recording head is manufactured by providing a liquid passage wall member 501 and an upper board 502 on a substrate having an electrothermal converting element and a semiconductor element.

For the recording head using the semiconductor device manufactured as described above, cells having a plurality of semiconductor elements in FIG. 7B were connected like a matrix, and operation experiments were performed. In the operation test, eight semiconductor diodes were connected to one segment and 300mA (2.4A total) of current flowed through each diode. However, other semiconductor diodes did not malfunction, and liquid droplets could be properly released. The present invention is also applicable to PNP transistor configurations.

12 is a schematic perspective view of the ink jet recording apparatus in which the recording head of the present invention is installed.

The means for replenishing the recording paper 808 as a recording medium includes a printing plate roller 804 and an axis 806 for rotating the printing plate roller in the direction indicated by the arrow A. FIG. An ink tank integrated head 818 is mounted on the carriage 814, which is guided and reciprocated by two guide shafts 810 and 812. The head 818 makes recording by releasing ink while moving along the recording paper surface. Reference numeral 816 denotes a flexible cable for transmitting a drive signal for driving the electrothermal converting element of the recording head and a bias signal for biasing the semiconductor substrate and the isolation region.

13 shows the recording head 818. The head shown in FIG. 4A is assembled in the ink tank 824. An electrical connection terminal 820 is disposed below the head 818. Reference numeral 838 denotes a carriage side connection terminal electrically connected to the flexible cable and coupled to the connection terminal 820 of the head 818. The carriage side connection terminal 838 and the head side connection terminal 820 include contacts for transmitting a driving signal and contacts for transmitting a bias signal, respectively.

Experimental Example

The heads of the first and second embodiments described above and the heads of the structural examples shown in US Pat. No. 4,429,321, which were displayed as conventional examples, were prepared. Each head was driven with a drive signal having a pulse width of 300 mA and 10 μsec to evaluate the dot shift of the ejected ink droplets.

The evaluation method is as follows.

First, the driving pulse was input 100 times and ink droplets were discharged from the same discharge port. Ink droplets located relatively farthest were selected from ink droplets affixed to the surface of the recording paper, and the distance was set to the maximum deviation (? Max). The head is kept running for 1 hour, but the maximum deviation (? Max) is calculated from the samples obtained at each of the initial stages, after 10 minutes, after 30 minutes and after 1 hour. the results are as follow.

Unit: μm (wherein all diameters of the attached dots were 100 μm)

As described above, according to the embodiment of the present invention, even when the head is used for a long time, the emission characteristics are stable and a good image is obtained. On the other hand, according to the conventional configuration, a problem occurs when the head is used for a long time even though such a big problem does not occur in the initial stage.

Although their reasons are complex, the generation of microbubbles in the ink is reduced because of the very good switching characteristics of the device and the film boiling phenomenon with good control occurs and is stable for a long time.

As described above, according to the present exemplary embodiment, each of the plurality of semiconductor devices has high breakdown voltage property and excellent electrical insulation performance, and all the devices may be formed on a single substrate. Therefore, for example, in a circuit composed of semiconductor elements connected in a matrix manner, there is no need to connect the elements individually from the outside, and the number of steps can be reduced. Therefore, the number of failure occurrence positions can be reduced and high reliability can be ensured.

Meanwhile, according to the embodiment, a semiconductor device and an electrothermal conversion device driven by the semiconductor device may be formed on the same substrate. Therefore, it is possible to obtain a recording head in which the circuit area is reduced, the number of processes is reduced, the reliability is improved, and a high resolution recording image can be formed.

This embodiment can be applied to semiconductor devices of various applications. For example, this embodiment can be applied as a diode for microcurrent. This embodiment can also be applied to large current diodes. However, as a great advantage of the present invention, it can be said that the semiconductor device of this embodiment is excellent in breakdown voltage characteristics and can be used with a large current. Therefore, the most representative advantage of this embodiment can be obtained when used as a device for high current.

Moreover, when the transistor is used as a semiconductor device, the driving voltage is applied to the emitter, the base and the collector are shorted and no minority carrier is injected between the base and the collector, so the switching speed is fast, the rising speed is improved, and the parasitic effect Can be alleviated, suitable thermal energy applied to the liquid and good emission characteristics can be obtained.

Claims (14)

In an ink jet recording head having an ejection opening for ejecting ink, electrothermal converting elements for generating thermal energy used to eject ink and transistor elements electrically connected to the electrothermal converting elements are formed on a semiconductor substrate, and And a base and a collector of the transistor element are short-circuited and electrically connected to the electrothermal converting element. In an ink jet recording head having an ejection opening for ejecting ink, an electrothermal converting element for generating thermal energy used to eject ink and a transistor element electrically connected to the electrothermal converting element are formed on a semiconductor substrate, and the transistor An ink jet recording head according to claim 1, wherein the base and the collector of the element are short-circuited and the emitter of the transistor element is electrically connected to the electrothermal converting element. The head according to claim 1 or 2, wherein the transistor element is an NPN transistor. The head according to claim 1 or 2, wherein the transistor element is formed on a semiconductor region formed on the P-type semiconductor substrate and formed by epitaxial growth. The head of claim 1, wherein the transistor element is formed on a semiconductor region formed on an N-type semiconductor substrate and formed by epitaxial growth. The head of claim 1, wherein the transistor element is formed on a semiconductor region formed on an N-type semiconductor substrate and formed by epitaxial growth. 2. The head of claim 1, wherein the transistor element is formed on a semiconductor region, the semiconductor element being formed on an N-type semiconductor substrate and surrounded by an isolation region at the periphery of the N-type semiconductor and maintained at a positive potential. 3. A head according to claim 2, wherein said transistor element is formed on a semiconductor region which is located on an N-type semiconductor substrate and whose periphery is formed of a P-type semiconductor and surrounded by an isolation region held at ground potential. The head according to claim 1, wherein the transistor element is formed on an N-type semiconductor substrate having an impurity concentration in the range of 1x10 ¹² to 1/10 ¹⁶ cm ^-3 . 3. The head of claim 2, wherein the transistor element is formed on a P-type semiconductor substrate having an impurity concentration in the range of 1x10 ¹² to 1x10 ¹⁶ cm ^-3 . The head according to claim 1 or 2, wherein the electrothermal converting element is formed as a thin film through an insulating film on the semiconductor region where the transistor element is formed. The head according to claim 1 or 2, wherein a plurality of the electrothermal converting elements and a plurality of the transistor elements are provided and connected in a matrix form. The semiconductor device of claim 2, wherein the transistor device comprises: an buried layer comprising an N-type semiconductor having an impurity concentration of 1 × 10 ¹⁹ cm ⁻³ or more; And a base region composed of a P-type semiconductor having an impurity concentration in the range of 1 × 10 ¹³ to 1 × 10 ¹⁵ cm ^-3 . An ink jet recording apparatus having a carriage on which a recording head according to claim 1 is mounted and a means for conveying a recording medium, said ink jet recording apparatus having bias means for biasing a semiconductor substrate of the recording head. An ink jet recording apparatus, characterized in that.

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