JP2008288252A - Process for fabricating functional element, photoelectric conversion element, image sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a process for fabricating a functional element in which deterioration in characteristics of the whole functional element can be prevented at a low cost while enhancing the characteristics of the functional film in the functional element. <P>SOLUTION: The process for fabricating a photoelectric conversion element having a pair of opposing electrodes 7 and 9, and a photoelectric conversion film 8 sandwiched between the electrodes 7 and 9 comprises a step for forming the photoelectric conversion film 8 on the electrode 7 (fig.2(a)), a step for forming the electrode 9 on the photoelectric conversion film 8 (fig.2(b)), a step for forming a deterioration prevention film 11 which prevents deterioration of the electrode 9 due to annealing for enhancing the characteristics of the photoelectric conversion film 8 on the electrode 9 (fig.2(c)), and an annealing step to be performed after formation of the deterioration prevention film 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a functional element having a pair of electrodes facing each other and a functional film sandwiched between the pair of electrodes.

  A photoelectric conversion element used for a solar cell or the like is formed by laminating a transparent electrode, a photoelectric conversion film, and an electrode on a substrate, and by inputting light from the substrate side, a signal corresponding to the charge generated in the photoelectric conversion film is externally transmitted. It is configured to take out. In addition, a light-emitting element used for an organic EL element or the like has a structure in which a transparent electrode, a light-emitting film, and an electrode are stacked on a substrate, and a voltage is applied to the transparent electrode to convert the light into a light and emit light. ing.

  In such photoelectric conversion elements and light emitting elements, functional film such as photoelectric conversion film or light emitting film is annealed to improve the characteristics of the functional film such as improvement of photoelectric conversion efficiency or light emission efficiency and durability. Has been reported. In such an annealing process, if the annealing temperature is increased in order to obtain higher performance improvement of the functional film, the surface of the functional film is altered, and conversely, the performance is deteriorated. Therefore, it is necessary to lower the annealing temperature. However, this does not provide a sufficient annealing effect, but also requires a long annealing process, which causes an increase in manufacturing costs.

  In Non-Patent Document 1, when manufacturing a photoelectric conversion element, a transparent electrode, a photoelectric conversion film, and an electrode are formed on a substrate in this order, and then an annealing process is performed using the electrode on the photoelectric conversion film as a protective film for the photoelectric conversion film. Thus, it has been proposed to prevent alteration of the surface of the photoelectric conversion film.

S.R.Forrest et all, Nature (vol.425, p158,2003)

  Since the method of Non-Patent Document 1 is a method for manufacturing a photoelectric conversion element applied to a solar cell, consideration is given to deterioration of the characteristics of the entire element due to the electrode on the photoelectric conversion film being altered by annealing. Not. When this photoelectric conversion element is applied to an imaging element, the electrode on the photoelectric conversion film is a transparent electrode, and light enters from above the transparent electrode. However, the surface of the transparent electrode is altered by the annealing process. If it is present (for example, unevenness is formed on the surface), incident light is scattered on the surface, and the light use efficiency is lowered. For this reason, the method of nonpatent literature 1 is not suitable as a manufacturing method of a photoelectric conversion element applied to an image sensor.

  Further, in the method of Non-Patent Document 1, when a photoelectric conversion element is applied to an imaging element, a transparent electrode formed on the photoelectric conversion film can be obtained by sufficiently increasing the annealing temperature to improve the characteristics of the photoelectric conversion film. Will deteriorate and the smoothness will deteriorate. When the photoelectric conversion element is used as a solar cell, this smoothness is not a problem. However, when the photoelectric conversion element is used as an image pickup element, the entire photoelectric conversion film cannot be biased uniformly. Since problems such as conduction affect the image quality, this is an important issue to be solved. If the annealing temperature is lowered, such a problem is eliminated, but conversely, the effect of improving the characteristics is weakened and the manufacturing cost is increased.

  The present invention has been made in view of the above circumstances, and it is possible to prevent deterioration of characteristics of the entire functional element at low cost while sufficiently improving the characteristics of the functional film of the functional element having the functional film. An object of the present invention is to provide a method for manufacturing a functional element.

  The method for producing a functional element of the present invention is a method for producing a functional element having a pair of electrodes facing each other and a functional film sandwiched between the pair of electrodes, wherein one of the pair of electrodes Preventing alteration of the other electrode due to the step of forming the functional film above, the step of forming the other of the pair of electrodes above the functional film, and an annealing treatment to improve the characteristics of the functional film Forming an alteration preventing film on the other electrode, and performing the annealing treatment after the alteration preventing film is formed.

  In the method for producing a functional element of the present invention, the temperature of the annealing treatment is lower than the temperature at which the alteration preventing film peels from the other electrode.

  In the method for producing a functional element of the present invention, the alteration preventing film is not substantially altered before and after the annealing treatment.

  In the method for producing a functional element of the present invention, the alteration preventing film is transparent to incident light.

  In the method for producing a functional element of the present invention, the other electrode is a transparent conductive oxide, and the alteration preventing film is an inorganic silicon compound or an inorganic oxide.

  The method for producing a functional element of the present invention includes a step of removing the alteration preventing film after the annealing treatment.

  In the functional element manufacturing method of the present invention, the functional film includes an organic material.

  In the method for producing a functional element of the present invention, the organic material is an organic semiconductor.

  In the method for producing a functional element of the present invention, the thickness of the other electrode is 20 nm or less.

  In the method for producing a functional element of the present invention, the functional film is a photoelectric conversion film that generates charges according to light absorbed by absorbing incident light.

  In the functional element manufacturing method of the present invention, the other electrode of the functional element is an electrode on the incident side of the incident light.

  In the method for producing a functional element of the present invention, the functional film is a light emitting film that converts electric energy into light and emits it.

  In the functional element manufacturing method of the present invention, the other electrode of the functional element is an electrode on the extraction side of the emitted light.

  The photoelectric conversion element of the present invention is a functional element formed above the substrate and manufactured by the functional element manufacturing method, and a charge storage unit for storing charges generated in the photoelectric conversion film of the functional element And a connection portion that electrically connects one of the pair of electrodes and the charge storage portion.

  The imaging device of the present invention includes a plurality of the photoelectric conversion elements arranged on the same surface, and a signal reading unit that reads a signal corresponding to the charge generated in the photoelectric conversion element and accumulated in the charge accumulation unit. .

  According to the present invention, there is provided a method for manufacturing a functional element capable of preventing characteristic deterioration of the entire functional element at low cost while improving the characteristics of the functional film of the functional element having the functional film. Can do.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of one pixel of an image sensor that is an embodiment of the present invention. The image sensor of this embodiment has a configuration in which a plurality of pixels shown in FIG. 1 are arranged in a one-dimensional or two-dimensional manner on the same surface.
The imaging device shown in FIG. 1 includes a lower electrode 7 and a photoelectric conversion film 8 formed above the lower electrode 7 above a semiconductor substrate including an n-type semiconductor substrate 1 and a p-well layer 2 formed thereon. The photoelectric conversion element including the upper electrode 9 formed above the photoelectric conversion film 8 is laminated with the lower electrode 7 facing the semiconductor substrate side.

  The lower electrode 7 is a thin film of a conductive material divided for each pixel, and for example, aluminum or ITO is used. The lower electrode 7 is preferably made of a highly reflective conductive material such as aluminum or silver. By using a highly reflective material, light that has passed through the photoelectric conversion film 8 and entered the lower electrode 7 can be reflected and re-entered into the photoelectric conversion film 8, and charges generated in the photoelectric conversion film 8. This is because the amount can be increased.

  The photoelectric conversion film 8 is a layer shared by all pixels, absorbs light in a specific wavelength region, and generates signal charges (electrons and holes) corresponding to the light. The photoelectric conversion layer 8 includes an organic photoelectric conversion material such as an organic semiconductor. The photoelectric conversion film 8 may be a film composed of a single organic photoelectric conversion material or may be a film in which a plurality of photoelectric conversion materials are stacked. In the present embodiment, the photoelectric conversion film 8 is, for example, an organic photoelectric conversion material (for example, quinacridone) that absorbs light in the green wavelength range, or an absorption peak wavelength of an absorption spectrum between the visible range and the infrared range is the infrared range. It demonstrates as what was comprised including the organic photoelectric conversion material (for example, tin phthalocyanine) which exists in (wavelength 700nm or more). The photoelectric conversion film 8 may be divided for each pixel.

The upper electrode 9 is a thin film of a highly transparent conductive material shared by all pixels. A wiring (not shown) is connected to the upper electrode 9 so that a predetermined bias voltage is applied. A transparent protective film 10 is formed on the upper electrode 9. Since the upper electrode 9 needs to make incident light incident on the photoelectric conversion film 8, it is made of a conductive material that is transparent to the incident light. As a material of the upper electrode 9, a transparent conductive oxide (TCO) having a high transmittance with respect to visible light and infrared light and a small resistance value can be preferably used. A metal thin film such as Au can also be used. However, if an attempt is made to obtain a transmittance of 90% or more, the resistance value increases drastically, so TCO is preferable. In particular, ITO, IZO, AZO, FTO, SnO ₂ , TiO ₂ , ZnO _{2 and the} like can be preferably used as TCO. The upper electrode 9 may be divided for each pixel. 1 has a configuration in which light is incident from above the upper electrode 9, the upper electrode 9 serves as an electrode on the light incident side.

  The polarity of the bias voltage applied to the upper electrode 9 may be determined such that electrons out of the charges generated in the photoelectric conversion film 8 move to the lower electrode 7 and holes move to the upper electrode 9. In many cases, a reverse bias voltage may be applied.

  Between the upper electrode 9 and the photoelectric conversion film 8, a material film having a charge blocking function and a charge transport function that suppresses injection of charges that cause dark current from the upper electrode 9 into the photoelectric conversion film 8. A material film having an exciton blocking function and a charge transport function may be provided. Between the lower electrode 7 and the photoelectric conversion film 8, a material film having a charge blocking function and a charge transport function for suppressing the injection of charges that cause dark current from the lower electrode 7 to the photoelectric conversion film 8 A material film having an exciton blocking function and a charge transport function may be provided.

  A high concentration n-type impurity layer (n + layer) 3 for accumulating electrons generated in the photoelectric conversion film 8 and moved to the lower electrode 7 is formed in the p-well layer 2. A via plug 5 made of a conductive material such as aluminum is formed on the n + layer 3, and a lower electrode 7 is formed on the via plug 5. The lower electrode 7 and the n + layer 3 are electrically connected by the via plug 5. The via plug 5 is embedded in an opening provided in an insulating film 6 formed on the semiconductor substrate.

  In the p-well layer 2 and on the surface of the p-well layer 2, a signal readout unit 4 is formed for converting electrons accumulated in the n + layer 3 into a voltage signal and outputting the voltage signal to the outside of the imaging device. The signal reading unit 4 is configured by a known CMOS circuit including a source follower circuit that converts electrons accumulated in the n + layer 3 into a voltage signal and a reset transistor that resets electrons accumulated in the n + layer 3. , The charge accumulated in the n + layer 3 is converted into a signal corresponding to the amount and output. The signal reading unit 4 may be configured to transfer the charge accumulated in the n + layer 3 to the amplifier by the CCD and output a signal corresponding to the charge amount by the amplifier.

  In FIG. 1, the lower electrode 7 and the n + layer 3 are connected by the via plug 5. However, the polarity of the bias voltage applied to the upper electrode 9 is reversed, and the upper electrode 9 and the n + layer 3 are connected by the via plug 5. It is good also as a structure connected by.

The operation of the image sensor having the above configuration will be described.
When the exposure period starts, green light or infrared light in the incident light is absorbed by the photoelectric conversion film 8, and charges corresponding to the green light amount or the infrared light amount are generated here. Due to the bias voltage applied between the upper electrode 9 and the lower electrode 7, electrons generated in the photoelectric conversion film 8 move to the lower electrode 7 and then move to the n + layer 3 through the via plug 5, Accumulated. After the exposure period, a signal corresponding to the electrons accumulated in the n + layer 3 is output to the outside of the image sensor, and a monochrome image or an infrared signal corresponding to the green signal is output by the signal processing unit of the image pickup apparatus equipped with this image sensor. An infrared image corresponding to is generated.

Next, a manufacturing method of the image sensor shown in FIG. 1 will be described.
FIG. 2 is a process diagram showing a manufacturing process of the photoelectric conversion element formed above the semiconductor substrate of the imaging element shown in FIG.
First, a lower electrode 7 is formed by forming a conductive material such as aluminum, silver, and ITO on a substrate such as glass, quartz, or silicon (not shown) by, for example, CVD or sputtering, and quinacridone is formed on the lower electrode 7. An organic photoelectric conversion material such as tin phthalocyanine is deposited by, for example, resistance heating vapor deposition to form the photoelectric conversion film 8. Next, as shown in FIG. 2B, an upper electrode 9 is formed on the photoelectric conversion film 8 by depositing TCO by a CVD method or a sputtering method.

  In this manufacturing method, after the formation of the upper electrode 9, an annealing process for heating the entire element is performed in order to improve the photoelectric conversion efficiency and durability of the photoelectric conversion film 8, but the annealing process is performed with the upper electrode 9 exposed. If it performs, the upper electrode 9 will change in quality (for example, the surface will be uneven | corrugated), and the smoothness of the upper electrode 9 will be impaired. In order to maintain the smoothness, it is necessary to lower the annealing temperature. However, in this case, the improvement in characteristics of the photoelectric conversion film 8 cannot be expected so much, and it takes an annealing time and increases the manufacturing cost.

  Therefore, in this embodiment, before performing the annealing process, as shown in FIG. 2C, the alteration preventing film 11 for preventing the upper electrode 9 from being altered by the annealing process is provided on the surface of the upper electrode 9. In this state, the annealing process is performed. This annealing process is performed at a temperature lower than the peeling temperature at which the alteration preventing film 11 peels from the upper electrode 9. This is because the alteration preventing function of the upper electrode 9 cannot be exhibited if the alteration preventing film 11 is peeled off during the annealing process. By performing the annealing process through the alteration preventing film 11, the alteration of the upper electrode 9 can be prevented, the annealing temperature can be raised to improve the characteristics of the photoelectric conversion film 8, and the annealing process is performed. The manufacturing cost can be reduced by shortening the time. Further, since the smoothness of the upper electrode 9 can be maintained, there is no conduction or disconnection, and image quality can be improved.

  The first condition of the alteration preventing film 11 necessary for obtaining such an effect is that it is made of a material having high adhesion to the upper electrode 9. This is because if the adhesiveness is low, the upper electrode 9 is altered in the gap between the upper electrode 9 and the alteration preventing film 11, which is not preferable. The adhesion force between the upper electrode 9 and the alteration preventing film 11 needs to be at least 1 mN (millinewton), and if it is smaller than this, peeling or the like occurs and a sufficient alteration preventing effect cannot be obtained.

  The second condition is that the material is easily peeled from the upper electrode 9 by a method other than heat treatment, for example, a peeling method using a Kapton tape. This is because the alteration preventing film 11 is necessary in the manufacturing process and is essentially unnecessary for the photoelectric conversion element. Therefore, the alteration is prevented by attaching a Kapton tape to the alteration preventing film 11 and peeling it off. The prevention film 11 needs to be removed. If the alteration prevention film 11 remains on the upper electrode 9 at the time of peeling, the smoothness of the member formed in an upper layer than the upper electrode 9 cannot be maintained. . The adhesion between the upper electrode 9 and the alteration preventing film 11 needs to be at least smaller than the adhesive strength of a general tape, and is preferably 10 N (Newton) or less, preferably 1 N or less. Eleven combinations may be selected.

  The material of the anti-altering film 11 that satisfies the first and second conditions is determined in consideration of the material of the upper electrode 9. However, when the upper electrode 9 is made of TCO, in most cases, if it is a metal such as aluminum. The conditions of 1 and 2 can be satisfied. However, a soft metal such as indium is difficult to completely peel off and is not suitable as an alteration preventing film.

  Although the alteration preventing film 11 is unnecessary for the photoelectric conversion element, it is not preferable in terms of manufacturing cost to add a process for removing the film. Therefore, it may be considered that the alteration preventing film 11 remains. In this case, the alteration preventing film 11 is made of a material that does not substantially change before and after the annealing treatment (third condition) and transparent to incident light (transmits incident light of about 80% or more). It is necessary to use an insulating material (fourth condition) and the first condition.

  The reason for using an insulating material transparent to incident light is that light needs to be incident on the photoelectric conversion film 8. Also, the reason for using a material that does not substantially change before and after the annealing treatment is that if the alteration preventing film 11 is altered by the annealing treatment, the smoothness of the member formed above the upper electrode 9 cannot be maintained. This is because the direction of the light transmitted through the alteration preventing film 11 is changed to make it difficult to reach the photoelectric conversion film 8.

The material of the alteration preventing film 11 that satisfies the conditions of the first, third, and fourth conditions is determined by the balance with the material of the upper electrode 9, but when the upper electrode 9 is made of TCO, an inorganic silicon compound (for example, SiN) or an inorganic oxide is used. If it is a thing (for example, SiO ₂ ), the first, third, and fourth conditions can be satisfied in most cases.

  If the thickness of the alteration preventing film 11 is too thin, the function of preventing alteration is not sufficiently exhibited, and further alteration of the alteration preventing film itself occurs, so that an appropriate thickness is required. On the other hand, if the thickness is too thick, the alteration preventing film remains at the time of peeling or the film formation time becomes long, which causes an increase in cost. Considering the above, the thickness of the alteration preventing film 11 is preferably 50 nm or more and 10 μm or less, and more preferably 100 nm or more and 1 μm or less.

  Next, after performing the annealing process in the state of FIG. 2C, the alteration preventing film 11 is formed as shown in FIG. 2D by applying the Kapton tape to the alteration preventing film 11 and peeling it off. This is removed to complete the photoelectric conversion element. As described above, the step of removing the alteration preventing film 11 may be omitted.

  Thus, according to this manufacturing method, since the annealing treatment is performed after the alteration preventing film 11 is formed in close contact with the surface of the upper electrode 9, the photoelectric conversion is performed without altering the upper electrode 9 and the photoelectric conversion film 8. The characteristics of the film 8 can be improved. Moreover, since the upper electrode 9 can be prevented from being altered, the upper electrode 9 can be made smooth. Therefore, scattering of light on the surface of the upper electrode 9 can be prevented to increase the light use efficiency, the entire photoelectric conversion film 8 can be biased uniformly, and the lower electrode 7 and the upper electrode 9 are electrically connected, It is possible to prevent the upper electrode 9 from being disconnected. As a result, the image quality of the image sensor can be improved.

  Further, according to this manufacturing method, depending on the material of the alteration preventing film 11, the annealing temperature can be increased, so that the annealing time can be shortened and the manufacturing cost can be reduced. Further, according to this manufacturing method, the alteration preventing film 11 can be easily removed after the annealing treatment, so that the influence on the characteristics of the photoelectric conversion element due to the provision of the alteration preventing film 11 can be eliminated.

  In the case where the alteration preventing film 11 is left, the alteration preventing film 11 functions as a protective film for protecting the photoelectric conversion element. For this reason, if the protective film and the alteration preventing film 11 that have been conventionally required can be made of the same material, various effects can be obtained only by adding an annealing process to the conventional manufacturing process. High nature.

  Moreover, if the upper electrode 9 has a sufficient thickness, the above-described phenomenon such as conduction and disconnection is unlikely to occur. For this reason, the effect by this manufacturing method becomes remarkable when the thickness of the upper electrode 9 is as thin as 20 nm or less.

  The manufacturing method of the photoelectric conversion element has been described above. However, if the photoelectric conversion film 8 in FIG. 2 is a light-emitting film that emits light according to the voltage applied to the lower electrode 7, the present manufacturing method is a light-emitting element. It is also applicable to. In this case, when a light emitting film containing an organic material such as an organic semiconductor is used, the effect of improving the characteristics by the annealing treatment can be obtained, which is particularly effective. In addition, when the photoelectric conversion film 8 is a light emitting film, the present manufacturing method is effective when the photoelectric conversion film 8 is configured to emit light to the upper electrode 9 side. This is because when the light is emitted to the lower electrode 7 side, the upper electrode 9 does not need to transmit light, and the thickness can be increased, so that there is almost no concern about conduction or disconnection, which affects the characteristics of the element. This is to give almost no. Further, even if the surface of the upper electrode 9 is made uneven by the annealing treatment, the emitted light is not related to the shape of the upper electrode 9.

  The photoelectric conversion element applied to the imaging element as described in the present embodiment needs to make the upper electrode 9 thin, and the light transmitted through the upper electrode 9 affects the output of the photoelectric conversion element. The manufacturing method as described above is particularly effective.

  Examples of the present invention will be described below.

(Example 1)
A 25 mm square glass substrate with an ITO electrode was ultrasonically cleaned with acetone, semicoclean, and isopropyl alcohol (IPA) for 15 minutes. Finally, after IPA boiling cleaning, UV / O ₃ cleaning was performed. The substrate was moved to the organic vapor deposition chamber, and the pressure in the chamber was reduced to 1 × 10 ⁻⁴ Pa or less. Then, while rotating the substrate holder, 2-TNATA (tris (-(2-naphthyl) -phenyl-amino) triphenylamine) was deposited on the ITO electrode as an electron blocking layer by a resistance heating method at a rate of 0.5 to 1 mm / min. The vapor deposition was performed so that the thickness became 1000 mm in sec. Next, tin phthalocyanine purified by sublimation twice or more (manufactured by Aldrich Japan Co., Ltd.) and C60 (frontier carbon) subjected to sublimation purification by a resistance heating method while maintaining a deposition rate of 0.5 to 1 kg / sec, respectively, to a total of 700 kg. The photoelectric conversion layer was formed by vapor deposition. At this time, the ratio of the deposition rate of tin phthalocyanine and C60 was 1: 1.
Next, this substrate was transported to the sputtering chamber while maintaining a vacuum. Thereafter, ITO was deposited to a thickness of 50 mm as the upper electrode while keeping the room at 1 × 10 ⁻⁴ Pa or less. The area of the photoelectric conversion region formed by the lower electrode and the upper electrode was 2 mm × 2 mm. Next, the substrate was transferred to a CVD chamber while maintaining a vacuum, and a SiN ₂ film having a thickness of about 1 μm was formed on the upper electrode as an anti-altering film using a plasma CVD apparatus. Without exposing this board | substrate to air | atmosphere, it conveyed to the glove box which kept the water | moisture content and oxygen each 1 ppm or less, and sealed with the glass which put the moisture absorption agent using UV curable resin. The device thus fabricated was placed in an oven and annealed at 150 ° C. for 30 minutes in a nitrogen atmosphere.

The element after annealing was subjected to 5.0 × 10 ⁵ V / cm with the upper electrode being positively biased between the upper electrode and the lower electrode using an Optel constant energy quantum efficiency measurement device (source meter using Keithley 6430). The IPCE was calculated by measuring the dark current value that flows when no light is applied and the photocurrent value that flows when light is applied. The area of the photoelectric conversion region was irradiated with light from the upper electrode side in a region of 1.5 mmφ out of 2 mm × 2 mm. The amount of light irradiated was 50 μW / cm ² .

(Example 2)
An element was manufactured by changing the annealing temperature and annealing time of the annealing process in Example 1 to 250 ° C. and 10 minutes, respectively, and the same measurement as in Example 1 was performed.

(Comparative Example 1)
After carrying out to ITO film-forming of an upper electrode similarly to Example 1, it sealed in the glove box, without forming an alteration prevention film. The device was placed in an oven and annealed at 150 ° C. for 30 minutes in a nitrogen atmosphere.

(Comparative Example 2)
An element was fabricated by changing the annealing temperature and annealing time of the annealing process in Comparative Example 1 to 150 ° C. and 10 minutes, respectively, and the same measurement as in Example 1 was performed.

(Comparative Example 3)
After carrying out to ITO film-forming of an upper electrode similarly to Example 1, it sealed in the glove box, without forming an alteration prevention film. Thereafter, the same measurement as in Example 1 was performed without annealing.

FIG. 3 is a diagram showing the conditions and results of Examples and Comparative Examples.
Comparison between Examples 1 and 2 and Comparative Example 3 reveals that the characteristics of the element can be improved by performing the annealing process. Further, it can be seen from comparison between Examples 1 and 2 and Comparative Examples 1 and 2 that the deterioration of the characteristics of the element can be prevented by performing the annealing treatment after providing the anti-degeneration film. Further, by comparing the first and second embodiments, if the alteration preventing film is provided, even if the annealing temperature is increased and the annealing time is shortened, the same characteristics as those of the first embodiment can be maintained. I understand.

1 is a schematic cross-sectional view of one pixel of an image sensor according to an embodiment of the present invention. Process drawing which shows the manufacturing process of the photoelectric conversion element formed above the semiconductor substrate of the image pick-up element shown in FIG. The figure which showed the conditions and result of an Example and a comparative example

Explanation of symbols

7 Lower electrode 8 Photoelectric conversion film 9 Upper electrode 11 Anti-alteration film

Claims (15)

A method of manufacturing a functional element having a pair of electrodes facing each other and a functional film sandwiched between the pair of electrodes,
Forming the functional film over one of the pair of electrodes;
Forming the other of the pair of electrodes above the functional film;
Forming an alteration preventing film on the other electrode for preventing alteration of the other electrode by annealing performed to improve the characteristics of the functional film;
And a step of performing the annealing treatment after forming the alteration preventing film. It is a manufacturing method of the functional element according to claim 1,
A method for producing a functional element, wherein a temperature of the annealing treatment is lower than a temperature at which the alteration preventing film peels off from the other electrode. A method for producing a functional element according to claim 1 or 2,
The method for producing a functional element, wherein the alteration preventing film is substantially not altered before and after the annealing treatment. A method for producing a functional element according to any one of claims 1 to 3,
A method for producing a functional element, wherein the alteration preventing film is transparent to incident light. A method for producing a functional element according to any one of claims 1 to 4,
The other electrode is a transparent conductive oxide;
A method for producing a functional element, wherein the alteration preventing film is an inorganic silicon compound or an inorganic oxide. A method for producing a functional element according to claim 1 or 2,
A method for manufacturing a functional element, comprising a step of removing the alteration preventing film after the annealing treatment. A method for producing a functional element according to any one of claims 1 to 6,
A method for producing a functional element, wherein the functional film includes an organic material. It is a manufacturing method of the functional element according to claim 7,
A method for producing a functional element, wherein the organic material is an organic semiconductor. A method for manufacturing a functional element according to any one of claims 1 to 8,
A method for producing a functional element, wherein the thickness of the other electrode is 20 nm or less. A method for manufacturing a functional element according to any one of claims 1 to 9,
A method for producing a functional element, wherein the functional film is a photoelectric conversion film that absorbs incident light and generates charges according to the absorbed light. It is a manufacturing method of the functional element according to claim 10,
The method for producing a functional element, wherein the other electrode of the functional element is an electrode on the incident side of the incident light. A method for manufacturing a functional element according to any one of claims 1 to 9,
A method for producing a functional element, wherein the functional film is a light-emitting film that converts electric energy into light and emits the light. It is a manufacturing method of the functional element according to claim 12,
The method for producing a functional element, wherein the other electrode of the functional element is an electrode on the extraction side of the emitted light. A functional element formed above the substrate and manufactured by the method for manufacturing a functional element according to claim 10 or 11,
A charge storage unit for storing charges generated in the photoelectric conversion film of the functional element;
A photoelectric conversion element comprising a connection portion that electrically connects one of the pair of electrodes to the charge storage portion. A plurality of the photoelectric conversion elements according to claim 14 arranged on the same surface;
An image pickup device comprising: a signal reading unit that reads a signal corresponding to the electric charge generated by the photoelectric conversion device and stored in the charge storage unit.

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