JP2015109384A - Substrate with organic functional layer, and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate with an organic functional layer having a protective film which does not cause a loss due to reflected light, has membrane stress within a predetermined range, and has excellent stability under high temperature and high humidity environment, and to provide a manufacturing method of the substrate.SOLUTION: A substrate with organic functional layer has: a base material; an organic functional layer arranged on the base material having heat resistance of 245°C or less; and a protective film arranged on the organic functional layer. The protective film has a plurality of silicon oxynitride layers expressed in SiOxNy, each silicon oxynitride layer has a refractive index difference within 0.1 in an absolute value, where x and y satisfy 0.5≤x≤1.0 and -2.2y+2.1≤x≤-2.2y+2.41. In the protective film, a silicon oxynitride layer farther from the organic functional layer out of the plurality of silicon oxynitride layers has a larger value of x than that of a silicon oxynitride layer formed at a position closest to the organic functional layer by 0.05 or more.

Description

  The present invention relates to a substrate with an organic functional layer having a protective film for protecting the organic functional layer and a method for producing the same, and more particularly, a substrate with an organic functional layer applicable to a color filter, an image sensor, an organic solar battery, an organic EL, and the like. It relates to the manufacturing method.

  Conventionally, a color imaging device using an organic photoelectric conversion layer has been proposed. A conventional color imaging device includes a pixel electrode formed on a semiconductor substrate on which a signal readout circuit is formed, an organic photoelectric conversion layer formed on the pixel electrode, and a counter electrode ( An upper electrode), a protective film formed on the counter electrode and protecting the counter electrode, a color filter, and the like. The protective film is composed of a SiOxNy film formed by a plasma CVD method. Various types of such protective films have been conventionally proposed (see Patent Documents 1 and 2 and Non-Patent Document 1).

  Patent Document 1 describes an imaging device having an organic photoelectric conversion layer that uses a silicon oxynitride film (SiOxNy film) formed by a plasma CVD method as a protective film for protecting a counter electrode. When this protective film is a single layer, it is described that the internal stress of the entire protective film is -50 MPa to +60 MPa.

Patent Document 2 discloses a gas barrier in which a solvent-resistant layer (acrylic cured resin), a cardo polymer layer (epoxy cured resin), and a silicon oxynitride layer are formed in this order on both surfaces of a polyimide film. A film is described. It is described that this silicon oxynitride layer is formed by a plasma CVD method.
In addition, a SiOxNy layer is formed as a gas barrier layer by sputtering on a solvent resistant layer (acrylic cured resin), a cardo polymer layer is formed thereon, and a silicon oxynitride layer is formed on the cardo polymer layer. A gas barrier film formed of is described.
Patent Document 2 describes that x = 0.5 to 1.5 and y = 0.15 to 1 as the composition of SiNxOy suitable for the barrier property. A preferred range for x is 0.5 to 1.5, a more preferred range is 0.7 to 1.3, a preferred range for y is 0.15 to 1, and a more preferred range is 0.3 to 0.7. ing.

  Non-Patent Document 1 describes a transparent gas barrier material in which a SiON film is formed on a PET substrate by reactive sputtering. Non-Patent Document 1 shows the relationship between the composition of the SiOxNy film and the oxygen permeability. Non-Patent Document 1 shows that gas barrier properties are improved by increasing x from 0.6 to 1.0.

JP 2013-118363 A JP 2009-241483 A

S. Iwamori et al. Vacuum 68 (2003) 113-117.

As described above, Patent Documents 1 to 3 describe the internal stress, film composition, and gas barrier properties of the SiOxNy film used as the protective film. However, when the compressive stress of the SiOxNy film is large, the film peels off, and when a tensile stress acts, a predetermined gas barrier property cannot be obtained. As described above, depending on the state of the film stress, the film is peeled off and the gas barrier property is lowered, and there is an appropriate range as the film stress. The SiOxNy film with improved gas barrier properties has high film stress and may be peeled off.
Further, Patent Documents 1 to 3 do not describe anything about the stability of the SiOxNy film at high temperature and high humidity, and do not take into account the wet heat storage stability.
At present, there is no SiOxNy film used as a protective film that has the above-mentioned appropriate film stress and does not deteriorate the gas barrier performance even in a high temperature and high humidity environment.

  The object of the present invention is to solve the above-mentioned problems based on the prior art, and to provide a protective film having no loss due to reflected light, having a film stress within a predetermined range, and excellent stability in a high temperature and high humidity environment. It is to provide a substrate with an organic functional layer and a method for producing the same.

  In order to achieve the above object, a first aspect of the present invention includes a base material, an organic functional layer having a heat resistance of 245 ° C. or less disposed on the base material, and a protection disposed on the organic functional layer. The protective film has a plurality of silicon oxynitride layers represented by SiOxNy, and each silicon oxynitride layer has a refractive index difference of 0.1 or less in absolute value, more preferably 0.05 or less. X and y satisfy 0.5 ≦ x ≦ 1.0 and −2.2y + 2.1 ≦ x ≦ −2.2y + 2.41, and the protective film includes a plurality of silicon oxynitride layers. The organic oxynitride layer far from the organic functional layer has an x value that is 0.05 or more larger than the x value of the silicon oxynitride layer formed closest to the organic functional layer. A substrate with a functional layer is provided.

The protective film may have another layer between the silicon oxynitride layers.
For example, the organic functional layer is an organic photoelectric conversion layer that generates charges when irradiated with light, and the organic photoelectric conversion layer is provided with a lower electrode on the substrate side and a transparent upper electrode on the opposite side of the substrate It is preferable that a protective film is disposed on the upper electrode.
Further, for example, the organic functional layer is a color filter layer containing an organic substance, and a protective film is disposed on the color filter layer.
Note that x and y preferably satisfy 0.5 ≦ x ≦ 1.0 and −2.2y + 2.1 ≦ x ≦ −2.2y + 2.32.

  According to a second aspect of the present invention, a plurality of silicon oxynitride layers represented by SiOxNy are formed on a functional organic layer having a heat resistance of 245 ° C. or lower disposed on a substrate by using a plasma CVD method. In the protective film forming step, the silicon oxynitride layer far from the organic functional layer is changed by changing only the high frequency power among the film forming conditions in the plasma CVD method. The silicon oxynitride layer formed at a position closest to the organic functional layer is formed with a composition larger than 0.05 by x, more preferably 0.1 or more, and even more preferably 0.15 or more. A method for producing a substrate with an organic functional layer is provided.

ADVANTAGE OF THE INVENTION According to this invention, the board | substrate with an organic functional layer which has the protective film which can suppress the loss by reflected light, has a film stress in the predetermined range, and was excellent in stability in a high temperature, high humidity environment is provided. it can. In particular, when an organic photoelectric conversion layer is used for the organic functional layer, sensitivity loss due to reflected light can be reduced.
In addition, according to the present invention, a substrate with an organic functional layer that can suppress a loss due to reflected light, has a film stress within a predetermined range, and has a protective film excellent in stability under a high temperature and high humidity environment is manufactured. be able to.

(A) is a schematic diagram which shows the board | substrate with an organic functional layer of embodiment of this invention, (b) is a schematic diagram which shows the other example of the board | substrate with an organic functional layer of embodiment of this invention, (C) is a schematic diagram which shows the other example of the board | substrate with an organic functional layer of embodiment of this invention, (d) is a protective film formed in the board | substrate with an organic functional layer of Fig.1 (a). It is a schematic diagram which shows the previous state. (A) is typical sectional drawing which shows the image sensor of embodiment of this invention, (b) is typical sectional drawing which shows the other example of the image sensor of embodiment of this invention. (A) And (b) is typical sectional drawing which shows the manufacturing method of the image pick-up element of embodiment of this invention in order of a process. (A) And (b) is typical sectional drawing which shows the manufacturing method of the image pick-up element of embodiment of this invention in order of a process, and shows the post process of FIG.3 (b). (A) is typical sectional drawing which shows the organic solar cell of embodiment of this invention, (b) is typical sectional drawing which shows the organic EL element of embodiment of this invention. (A) And (b) is typical sectional drawing for demonstrating the stress which acts on the thin film each formed in the board | substrate. It is a schematic diagram which shows the measuring apparatus which measures the curvature amount of the board | substrate with which the thin film was formed.

Hereinafter, a substrate with an organic functional layer and a method for producing the same according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
FIG. 1A is a schematic diagram illustrating a substrate with an organic functional layer according to an embodiment of the present invention, and FIG. 1B is a schematic diagram illustrating another example of the substrate with an organic functional layer according to an embodiment of the present invention. And (c) is a schematic view showing another example of the substrate with an organic functional layer of the embodiment of the present invention, and (d) is a protective film formed on the substrate with the organic functional layer of FIG. 1 (a). It is a schematic diagram which shows the state before being performed.

As shown in FIG. 1A, the substrate 10 with an organic functional layer has a base material 12, an organic functional layer 14, and a protective film 16.
The substrate 12 supports the organic functional layer 14 and the protective film 16. The base material 12 can support the organic functional layer 14 and the protective film 16 and has a predetermined strength against heat and the like applied when the organic functional layer 14 and the protective film 16 are produced. For example, it is composed of a flat plate. As the base material 12, a glass base material, a metal base material with an insulating layer, a resin base material, a metal base material, etc. can be used, for example. In addition, about the base material 12, according to the kind etc. of the organic functional layer 14, a conductive or insulating base material can be used suitably.

The organic functional layer 14 includes an organic substance and exhibits a predetermined function, and has a heat resistance of 245 ° C. or lower. Examples of the organic functional layer 14 include an organic photoelectric conversion layer used for an image sensor, a photoelectric conversion layer containing an organic substance used for an organic solar cell, an organic EL layer used for an organic EL, and a color filter.
The organic functional layer 14 is used in the form of a single element such as a color filter, an organic photoelectric conversion layer used for an image sensor, a photoelectric conversion layer containing an organic substance used for an organic solar cell, and an organic EL layer. Are used.
The heat resistance is a temperature at which the function of the organic functional layer 14 can be maintained. In this invention, since it is 245 degrees C or less, when temperature exceeds 245 degreeC, the function of the organic functional layer 14 will be impaired. For example, in the case of a color filter, problems such as changes in transmittance and color occur, and the original spectral characteristics change. If it is an organic photoelectric conversion layer, performance degradation, such as a raise of a dark current, will arise. If it is an organic EL layer, light emission intensity will fall.

The protective film 16 is for protecting the organic functional layer 14. The protective film 16 has a function of protecting the organic functional layer 14 for a long time in a high temperature and high humidity environment, and functions as a barrier film.
The protective film 16 is a multilayer structure in which a plurality of silicon oxynitride layers represented by SiOxNy are stacked. In the example shown in FIG. 1A, the protective film 16 is a first silicon oxynitride layer 16a and a second silicon oxynitride layer 16b. However, the number of layers is not particularly limited. In addition, the protective film 16 in FIG. 1A is directly provided on the organic functional layer 14, but the arrangement of the protective film 16 is limited to this as long as the organic functional layer 14 can be protected. is not. For example, an electrode, a transparent electrode, another component or structure, etc. may be provided on the organic functional layer 14, and the protective film 16 may be provided on the electrode or other component or structure.

  In the silicon oxynitride layer constituting the protective film 16, x and y of SiOxNy are 0.5 ≦ x ≦ 1.0 and −2.2y + 2.1 ≦ x ≦ −2.2y + 2.41 (0.5 ≦ y ≦ 0.86) is satisfied. Preferably, 0.5 ≦ x ≦ 1.0 and −2.2y + 2.1 ≦ x ≦ −2.2y + 2.32 are satisfied.

In the protective film 16, the plurality of silicon oxynitride layers all have different compositions, and the silicon oxynitride layer far from the organic functional layer 14 among the plurality of silicon oxynitride layers has an x value as the organic functional layer. It is 0.05 or more larger than the value of x of the silicon oxynitride layer formed at the nearest position. Specifically, in the case of FIG. 1A, the first silicon oxynitride layer 16a is formed directly on the organic functional layer 14, and the second silicon oxynitride layer 16b is formed on the organic functional layer 14. This corresponds to the silicon oxynitride layer on the side far from the surface. For FIG. 1 (a), and a second silicon oxynitride layer 16b, is compared with the first silicon oxynitride layer 16a, the value of x of SiOxNy the second silicon oxynitride layer 16b and _{x 2,} when the value of x of SiOxNy the first silicon oxynitride layer 16a and _{x 1,} is x 1 + 0.05 ≦ _{x 2.}

In the case of two or more layers, the value of x of SiOxNy of the silicon oxynitride layer differs depending on the relative positional relationship with respect to the organic functional layer 14, and the value of x is at least 0.05 larger in order from the organic functional layer 14 side. In the protective film 16, as the silicon oxynitride layer becomes the uppermost layer, the value of x takes a larger value within the range of the composition. The uppermost layer of the protective film 16 preferably has a y value of 0.60 to 0.68, more preferably a y value of 0.62 to 0.66.
In addition, although the value of x is a composition larger by at least 0.05 or more, it is more preferably 0.1 or more, and even more preferably 0.15 or more.

  For example, when the protective film 16 has a three-layer structure of a first silicon oxynitride layer 16a to a third silicon oxynitride layer 17 as in the substrate 10a with an organic functional layer shown in FIG. Of the silicon oxynitride layer 16a to the third silicon oxynitride layer 17, the third silicon oxynitride layer 17 as the uppermost layer has the largest value of x within the above composition range. However, the present invention is not limited to this, and in the case of three or more layers, the configuration of the first silicon oxynitride layer 16a and the second silicon oxynitride layer 16b satisfies the above composition, and the first silicon oxynitride If the function of the protective film 16 can be exhibited by the layer 16a and the second silicon oxynitride layer 16b, the uppermost third silicon oxynitride layer 17 may not satisfy the above-described composition of the silicon oxynitride layer. .

On the contrary, the second silicon oxynitride layer 16b and the uppermost third silicon oxynitride layer 17 satisfy the above composition, and the second silicon oxynitride layer 16b and the uppermost third silicon oxynitride layer 17 If the function of the protective film 16 can be exhibited at 17, the first silicon oxynitride layer 16 a does not have to satisfy the above-described composition of the silicon oxynitride layer.
Further, the protective film 16 does not need to be the uppermost layer of the substrate with an organic functional layer, and a film may be further formed on the protective film 16. In this case, the structure and composition of the film are not particularly limited.

Further, there may be another component layer between the first silicon oxynitride layer 16a and the second silicon oxynitride layer 16b as in the substrate 10b with an organic functional layer shown in FIG. This other constituent layer is, for example, a transparent electrode, a resin layer, or an adhesive layer. The present invention can also be applied to the substrate 10a with an organic functional layer having a three-layer structure shown in FIG.
In the present invention, the total thickness is preferably 50 nm or more regardless of the configuration of the protective film 16.

With respect to SiOxNy, the protective film 16 is a silicon oxynitride layer that is transparent and has a stable film quality by being in the above composition range. Moreover, the refractive index is in the range of 1.65 to 1.75.
Here, the term “transparent” means that the light absorption rate is less than 0.2% in the wavelength range of 400 to 800 nm (visible light range). That is, the term “transparent” means that the light absorption rate in the wavelength range of 400 to 800 nm is a maximum value of less than 0.2%. If the light absorption rate in the visible light region is 0.2%, light absorption can be ignored.
When the protective film 16 is out of the above composition range, it is not transparent and the refractive index does not fall within the range of 1.65 to 1.75. “Not transparent” means that the light absorption rate in the visible light region is 0.2% or more.
In the protective film 16, each silicon oxynitride layer has an absolute value of a difference in refractive index within 0.1, more preferably within 0.05. Specifically, in the example shown in FIG. 1A, the refractive index difference between the first silicon oxynitride layer 16a and the second silicon oxynitride layer 16b is 0.1 or less in absolute value. Further, when the number of layers of the protective film 16 is 3 or more, the refractive index difference of all the silicon oxynitride layers is within 0.1 in absolute value. That is, in the protective film 16, the difference between the maximum value and the minimum value of the refractive index of the silicon oxynitride layer is within 0.1. Thereby, reflection of the incident light L at the interface between the first silicon oxynitride layer 16a and the second silicon oxynitride layer 16b of the protective film 16 can be suppressed. The refractive index difference is preferably within 0.03 in absolute value.

  Here, the durable silicon oxynitride layer (SiON film) has a large compressive film stress. To prevent film peeling by reducing the thickness of the protective film, the optical path length is changed, the reflectance of the incident light L is increased, and if the organic functional layer 14 is a photoelectric conversion layer, the sensitivity is decreased. Can not. In addition, in a single layer film, stress and durability are not compatible. Therefore, the film structure is a multi-layer structure, and the composition and refractive index difference of each layer are within the above-described range of the present invention, so that the high-stress layer is provided only on the surface without changing the overall film thickness. It is possible to achieve both suppression of peeling and suppression of increase in reflectance.

The protective film 16 is 2.20 (g / m ³ ) ≦ ρ ≦ 2.60 (g / m ³ ), where the density is ρ (g / m ³ ). Preferably, 2.30 (g / m ³ ) ≦ ρ ≦ 2.60 (g / m ³ ).

If the density ρ (g / m ³ ) is in the above range, the protective film 16 has a predetermined heat resistance and can protect the organic functional layer 14. When the density of the protective film 16 is less than 2.20 (g / m ³ ), predetermined heat resistance cannot be obtained. On the other hand, when the density of the protective film 16 exceeds 2.60 (g / m ³ ), the film stress of the protective film 16 increases and adversely affects the lower organic functional layer 14.

The protective film 16 represented by SiOxNy is formed by a plasma CVD method at a temperature of 245 ° C. or lower in a reaction chamber such as a process chamber from the viewpoint of heat resistance of the organic functional layer 14. By using the plasma CVD method, it is possible to form a film at a higher film formation rate than the vapor deposition method or the like.
In the substrate 10 with an organic functional layer in FIG. 1A, for example, as shown in FIG. 1D, after forming the organic functional layer 14 on the base material 12, the protective film 16 is formed on the organic functional layer 14. As described above, the silicon oxynitride layer having the above composition is formed by plasma CVD at a substrate temperature (film formation temperature) of 245 ° C. or lower. Regarding the composition and density of the silicon oxynitride layer, the silicon oxynitride layer is formed in advance by changing the flow rate of the reaction gas, and the film formation conditions (film formation temperature (substrate temperature), pressure in the reaction chamber during film formation ( (Hereinafter referred to as pressure during film formation), high-frequency power during film formation, gas type (SiH ₄ , NH ₃ , N ₂ O), gas mixing ratio, etc.) A silicon nitride layer can be formed.

  In the protective film 16, a plurality of silicon oxynitride layers are formed, each having a different composition. In this case, the value of x of the silicon oxynitride layer formed in the position closest to the organic functional layer 14 is changed by changing only the high-frequency power among the film formation conditions in the plasma CVD method. More than 0.05. In the case of a plurality of silicon oxynitride layers, a plurality of silicon oxynitride layers may be continuously formed by changing only the high-frequency power that is a film forming condition without stopping the supply of the source gas. Alternatively, a plurality of silicon oxynitride layers may be continuously formed by stopping the supply of the source gas and changing only the high frequency power. As described above, since a plurality of silicon oxynitride layers can be formed by changing the composition of the silicon oxynitride layer only by changing the high frequency power, the reaction in the process chamber or the like required for forming the plurality of silicon oxynitride layers One room is enough. For this reason, the time required for loading and unloading of the base material and the film forming atmosphere becomes unnecessary, and an increase in the film forming time of the protective film can be suppressed, and the production cost can be reduced.

  Further, the protective film 16 can be formed by changing the composition of the silicon oxynitride layer, whereby the film stress of the protective film 16 can be adjusted. The film stress and its measuring method will be described in detail later. The film stress of the protective film 16 is a stress value in the multilayer structure. Even if the protective film has another layer between the silicon oxynitride layers as shown in FIG. 1C, the film stress is the value of stress in the state of the multilayer structure.

Hereinafter, the specific example of the board | substrate with an organic functional layer of this invention is demonstrated. Specifically, the substrate with an organic functional layer of the present invention can be called, for example, an organic CMOS.
FIG. 2A is a schematic cross-sectional view illustrating an image sensor according to an embodiment of the present invention, and FIG. 2B is a schematic cross-sectional view illustrating another example of the image sensor according to the embodiment of the present invention.
The imaging element 20 shown in FIG. 2A is called an organic CMOS, and converts a visible light image into an electrical signal. The imaging device 20 includes a substrate 30, an insulating layer 32, a pixel electrode (lower electrode) 34, an organic layer 36, a counter electrode (upper electrode) 38, a protective film (sealing layer) 40, and a color filter 42. And a partition wall 44, a light shielding layer 46, and an overcoat layer 48. A reading circuit 60 and a counter electrode voltage supply unit 62 are formed on the substrate 30.

The board | substrate 30 is corresponded to the base material 12 (refer Fig.1 (a)) of this invention. As the substrate 30, for example, a glass substrate or a semiconductor substrate such as Si is used. An insulating layer 32 made of a known insulating material is formed on the substrate 30. A plurality of pixel electrodes 34 are formed on the surface of the insulating layer 32. The pixel electrodes 34 are arranged in a matrix on the surface 32a of the insulating layer 32, for example.
A first connection portion 64 that connects the pixel electrode 34 and the readout circuit 60 is formed in the insulating layer 32. Further, a second connection portion 66 that connects the counter electrode 38 and the counter electrode voltage supply unit 62 is formed. The second connection part 66 is formed at a position not connected to the pixel electrode 34 and the organic layer 36. The first connection part 64 and the second connection part 66 are made of a conductive material.

Inside the insulating layer 32, a wiring layer 68 made of a conductive material for connecting the readout circuit 60 and the counter electrode voltage supply unit 62 to, for example, the outside of the imaging element 20 is formed.
As described above, the circuit board 35 is formed by forming the pixel electrodes 34 connected to the first connection portions 64 on the surface 32 a of the insulating layer 32 on the substrate 30. The circuit board 35 is also referred to as a CMOS substrate.

An organic layer 36 is formed so as to cover the plurality of pixel electrodes 34 and avoid the second connection portion 66, and the organic layer 36 is formed across the plurality of pixel electrodes 34. The organic layer 36 receives incident light L including at least visible light and generates electric charges according to the amount of light, and includes a photoelectric conversion layer 52 and an electron blocking layer 50.
In the organic layer 36, the electron blocking layer 50 is formed on the pixel electrode 34 side, and the photoelectric conversion layer 52 is formed on the surface 50 a of the electron blocking layer 50. The organic layer 36 may be a single photoelectric conversion layer 52 without providing the electron blocking layer 50.

The electron blocking layer 50 is a layer for suppressing injection of electrons from the pixel electrode 34 to the photoelectric conversion layer 52.
The photoelectric conversion layer 52 generates charges according to the amount of incident light L, for example, received light such as visible light. The photoelectric conversion layer 52 is an organic photoelectric conversion layer mainly composed of an organic material, and is formed on the electron blocking layer 50 across the plurality of pixel electrodes 34.
As long as the photoelectric conversion layer 52 and the electron blocking layer 50 have a constant film thickness on the pixel electrode 34, the film thickness may not be constant otherwise. In this case, the film thickness is a thickness in a region where the film thickness is constant. The photoelectric conversion layer 52 will be described in detail later.

The counter electrode 38 is an electrode facing the pixel electrode 34, and is provided so as to cover the photoelectric conversion layer 52. A photoelectric conversion layer 52 is provided between the pixel electrode 34 and the counter electrode 38.
The counter electrode 38 is made of a conductive material that is transparent to the incident light L (light including at least visible light) in order to make light incident on the photoelectric conversion layer 52. The counter electrode 38 is electrically connected to the second connection portion 66 disposed outside the photoelectric conversion layer 52, and is connected to the counter electrode voltage supply portion 62 via the second connection portion 66. Yes.

  Examples of the material of the counter electrode 38 include metals, metal oxides, metal nitrides, metal borides, organic conductive compounds, and mixtures thereof. Specific examples include tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), indium tungsten oxide (IWO), conductive metal oxides such as titanium oxide, and metal nitrides such as TiN. Metal, gold (Au), platinum (Pt), silver (Ag), chromium (Cr), nickel (Ni), aluminum (Al), etc., and a mixture or laminate of these metals and conductive metal oxides Products, organic conductive compounds such as polyaniline, polythiophene, and polypyrrole, and laminates of these with ITO. Particularly preferable materials for the transparent conductive film are ITO, IZO, tin oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), zinc oxide, antimony-doped zinc oxide (AZO), gallium-doped zinc oxide ( GZO). A particularly preferable material among the materials of the counter electrode 38 is ITO.

The light transmittance of the counter electrode 38 is preferably 60% or more, more preferably 80% or more, more preferably 90% or more, and more preferably 95% or more in the visible light wavelength.
The counter electrode 38 preferably has a thickness of 5 to 30 nm. By making the counter electrode 38 have a thickness of 5 nm or more, the lower layer can be sufficiently covered, and uniform performance can be obtained. On the other hand, if the thickness of the counter electrode 38 exceeds 30 nm, the counter electrode 38 and the pixel electrode 34 may be locally short-circuited, resulting in an increase in dark current. By making the counter electrode 38 have a film thickness of 30 nm or less, the occurrence of a local short circuit can be suppressed.

  The counter electrode voltage supply unit 62 applies a predetermined voltage to the counter electrode 38 via the second connection unit 66. When the voltage to be applied to the counter electrode 38 is higher than the power supply voltage of the image sensor 20, the power supply voltage is boosted by a booster circuit such as a charge pump to supply the predetermined voltage.

  The pixel electrode 34 is an electrode for collecting charges for collecting charges generated in the photoelectric conversion layer 52. The pixel electrode 34 is connected to the readout circuit 60 via the first connection portion 64. The readout circuit 60 is provided on the substrate 30 corresponding to each of the plurality of pixel electrodes 34, and reads out a signal corresponding to the charge collected by the corresponding pixel electrode 34.

  Examples of the material of the pixel electrode 34 include metals, conductive metal oxides, metal nitrides and borides, organic conductive compounds, and mixtures thereof. Specific examples include tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), indium tungsten oxide (IWO), conductive metal oxides such as titanium oxide, and titanium nitride (TiN). , Conductive metal nitrides such as molybdenum nitride, tantalum nitride, tungsten nitride, metals such as gold (Au), platinum (Pt), silver (Ag), chromium (Cr), nickel (Ni), aluminum (Al), Furthermore, mixtures or laminates of these metals and conductive metal oxides, organic conductive compounds such as polyaniline, polythiophene and polypyrrole, laminates of these with ITO, and the like can be mentioned. Particularly preferable materials for the transparent conductive film are ITO, IZO, tin oxide, antimony-doped tin oxide (ATO), fluorine-doped tin oxide (FTO), zinc oxide, antimony-doped zinc oxide (AZO), gallium-doped zinc oxide ( GZO). Among the materials of the pixel electrode 34, a particularly preferable material is any one of titanium nitride, molybdenum nitride, tantalum nitride, and tungsten nitride.

The readout circuit 60 is constituted by, for example, a CCD, a MOS circuit, a TFT circuit, or the like, and is shielded from light by a light shielding layer (not shown) provided in the insulating layer 32. The readout circuit 60 is preferably a CMOS circuit from the viewpoint of noise and high speed.
Although not shown, for example, a high-concentration n region surrounded by a p region is formed on the substrate 30, and the first connection portion 64 is connected to the n region. A read circuit 60 is provided in the p region. The n region functions as a charge storage unit that stores the charge of the photoelectric conversion layer 52. The signal charge accumulated in the n region is converted into a signal corresponding to the amount of charge by the readout circuit 60 and output to the outside of the image sensor 20 or the like via the wiring layer 68, for example.

In the image sensor 20, the organic layer 36 corresponds to the organic functional layer of the present invention, and the heat resistance is 245 ° C. or lower. The protective film 40 is formed so as to cover the counter electrode 38. The protective film 40 is not directly provided on the organic layer 36. However, the protective film 40 can protect the organic layer 36 including the photoelectric conversion layer 52 from deterioration factors such as water molecules and oxygen.
The protective film 40 protects the organic layer 36 by preventing entry of factors that degrade the organic photoelectric conversion material contained in a solution such as an organic solvent, plasma, or the like in each manufacturing process of the imaging element 20. Further, after the image pickup device 20 is manufactured, the intrusion of factors that deteriorate the organic photoelectric conversion material such as water molecules and oxygen is prevented, and the deterioration of the organic layer 36 is prevented during long-term storage and long-term use. . Further, when the protective film 40 is formed, the already formed organic layer 36 is not deteriorated. Further, the incident light L reaches the organic layer 36 through the protective film 40. For this reason, the protective film 40 is transparent to light having a wavelength detected by the organic layer 36, for example, visible light.

The protective film 40 is the same multilayer structure as the protective film 16 described above. The protective film 40 has the same composition and density as the protective film 16 described above, and is formed by forming two silicon oxynitride layers represented by SiOxNy. The protective film 40 is formed by laminating a first silicon oxynitride layer 41a and a second silicon oxynitride layer 41b. The protective film 40 is formed by a plasma CVD method at a temperature of 245 ° C. or lower.
For example, the protective film 40 has a total film thickness of 50 to 500 nm.
If the total film thickness of the protective film 40 is less than 50 nm, the barrier property may be lowered, or the resistance of the color filter to the developer may be lowered. On the other hand, when the total thickness of the protective film 40 exceeds 500 nm, it is difficult to suppress color mixing when the pixel size is less than 1 μm.

  For example, in the imaging device 20 having a pixel size of less than 2 μm, particularly about 1 μm, if the distance between the color filter 42 and the photoelectric conversion layer 52, that is, the total film thickness of the protective film 40 is thick, The influence of the oblique incident component of the incident light (visible light) may increase, and color mixing may occur. For this reason, it is preferable that the total film thickness of the protective film 40 is thinner.

The color filter 42 is formed at a position facing each pixel electrode 34 on the protective film 40. The partition wall 44 is provided between the color filters 42 on the protective film 40 and is for improving the light transmission efficiency of the color filter 42. The light shielding layer 46 is formed in a region other than the region (effective pixel region) where the color filter 42 and the partition wall 44 are provided on the protective film 40, and light is incident on the photoelectric conversion layer 52 formed outside the effective pixel region. Is to prevent. The color filter 42, the partition wall 44, and the light shielding layer 46 are formed by, for example, a photolithography method.
Although the color filter 42 is provided, the color filter 42 may not be provided. In this case, since the partition wall 44 and the light shielding layer 46 are not provided in addition to the color filter 42, the protective film 40 is the uppermost layer. The protective film 40 may also have a configuration in which another constituent layer is provided between the first silicon oxynitride layer 41a and the second silicon oxynitride layer 41b, similarly to the protective film 16 described above.

The overcoat layer 48 is for protecting the color filter 42 from subsequent processes and is formed so as to cover the color filter 42, the partition wall 44 and the light shielding layer 46.
In the image sensor 20, one pixel electrode 34, on which the organic layer 36, the counter electrode 38, and the color filter 42 are provided, is a unit pixel.

For the overcoat layer 48, a polymer material such as an acrylic resin, a polysiloxane resin, a polystyrene resin, and a fluorine resin, or an inorganic material such as silicon oxide and silicon nitride can be used as appropriate. When a photosensitive resin such as polystyrene is used, the overcoat layer 48 can be patterned by a photolithography method, so that it is used as a photoresist when opening the peripheral light shielding layer, sealing layer, insulating layer, etc. on the bonding pad. The overcoat layer 48 itself is preferably processed as a microlens, which is preferable. On the other hand, it is also possible to use the overcoat layer 48 as an antireflection layer, and it is also preferable to form various low refractive index materials used as the partition walls of the color filter 42. In addition, in order to pursue a function as a protective layer and a function as an antireflection layer with respect to a subsequent process, the overcoat layer 48 can be configured to have two or more layers combining the above materials.
The color filter 42 contains an organic substance and corresponds to the organic functional layer of the present invention. For this reason, the overcoat layer 48 is formed by forming two silicon oxynitride layers represented by SiOxNy having the same composition and density as the above-described protective film 16, similarly to the above-described protective film 40. Also good. In this case, the overcoat layer 48 may be formed by laminating the first silicon oxynitride layer 48a and the second silicon oxynitride layer 48b as in the imaging device 20a shown in FIG. . 2B is the same component except that the configuration of the overcoat layer 48 is different from that of the image sensor 20 shown in FIG. Description is omitted.

The imaging element 20 can protect the organic layer 36 by the protective film 40 for a long time even in a severe environment of high temperature and high humidity such as a temperature of 85 ° C. and a relative humidity of 85%. For this reason, the image sensor 20 can be used without degrading performance for a long time even in the above-mentioned severe environment of high temperature and high humidity. For this reason, the image sensor 20 is suitable for applications where the use environment is severe such as a monitoring camera.
Further, the protective film 40 has a difference in refractive index within 0.1, preferably within 0.05, so that the generation of reflected light is suppressed, and the sensitivity loss in the image sensor 20 is small. Thereby, the efficiency of the image sensor 20 can be increased.

  In the present embodiment, the pixel electrode 34 is configured to be formed on the surface of the insulating layer 32, but is not limited thereto, and may be configured to be embedded in the surface portion of the insulating layer 32. In addition, the second connection portion 66 and one counter electrode voltage supply portion 62 are provided, but a plurality of the second connection portion 66 and the counter electrode voltage supply portion 62 may be provided. For example, a voltage drop at the counter electrode 38 can be suppressed by supplying a voltage from both ends of the counter electrode 38 to the counter electrode 38. The number of sets of the second connection portion 66 and the counter electrode voltage supply portion 62 may be appropriately increased or decreased in consideration of the chip area of the element.

Next, the photoelectric conversion layer 52 and the electron blocking layer 50 constituting the organic layer 36 will be described in more detail.
The photoelectric conversion layer 52 includes a p-type organic semiconductor material and an n-type organic semiconductor material. Exciton dissociation efficiency can be increased by joining a p-type organic semiconductor material and an n-type organic semiconductor material to form a donor-acceptor interface. For this reason, the photoelectric conversion layer of the structure which joined the p-type organic-semiconductor material and the n-type organic-semiconductor material expresses high photoelectric conversion efficiency. In particular, a photoelectric conversion layer in which a p-type organic semiconductor material and an n-type organic semiconductor material are mixed is preferable because the junction interface is increased and the photoelectric conversion efficiency is improved.

  The p-type organic semiconductor material (compound) is a donor-type organic semiconductor material (compound), which is mainly represented by a hole-transporting organic compound and refers to an organic compound having a property of easily donating electrons. More specifically, an organic compound having a smaller ionization potential when two organic materials are used in contact with each other. Therefore, any organic compound can be used as the donor organic compound as long as it is an electron-donating organic compound. For example, triarylamine compound, benzidine compound, pyrazoline compound, styrylamine compound, hydrazone compound, triphenylmethane compound, carbazole compound, polysilane compound, thiophene compound, phthalocyanine compound, cyanine compound, merocyanine compound, oxonol compound, polyamine compound, indole Compounds, pyrrole compounds, pyrazole compounds, polyarylene compounds, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives), nitrogen-containing heterocyclic compounds The metal complex etc. which it has as can be used. However, the present invention is not limited to this, and any organic compound having an ionization potential smaller than that of the organic compound used as the n-type (acceptor) compound as described above may be used as the donor organic semiconductor.

  The n-type organic semiconductor material (compound) is an acceptor organic semiconductor material, and is mainly represented by an electron-transporting organic compound and refers to an organic compound having a property of easily accepting electrons. More specifically, an n-type organic semiconductor refers to an organic compound having a larger electron affinity when two organic compounds are used in contact with each other. Therefore, any organic compound can be used as the acceptor organic compound as long as it is an electron-accepting organic compound. For example, condensed aromatic carbocyclic compounds (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives), 5- to 7-membered heterocyclic compounds containing nitrogen atoms, oxygen atoms, and sulfur atoms (E.g., pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, quinoxaline, quinazoline, phthalazine, cinnoline, isoquinoline, pteridine, acridine, phenazine, phenanthroline, tetrazole, pyrazole, imidazole, thiazole, oxazole, indazole, benzimidazole, benzotriazole , Benzoxazole, benzothiazole, carbazole, purine, triazolopyridazine, triazolopyrimidine, tetrazaindene, oxy Diazole, imidazopyridine, pyrrolidine, pyrrolopyridine, thiadiazolopyridine, dibenzazepine, tribenzazepine, etc.), polyarylene compounds, fluorene compounds, cyclopentadiene compounds, silyl compounds, nitrogen-containing heterocyclic compounds as ligands Etc. Not limited to this, as described above, any organic compound having an electron affinity higher than that of the organic compound used as the p-type (donor property) compound may be used as the acceptor organic semiconductor.

  Any organic dye may be used as the p-type organic semiconductor material or the n-type organic semiconductor material, but preferably a cyanine dye, a styryl dye, a hemicyanine dye, and a merocyanine dye (including zero methine merocyanine (simple merocyanine)). 3-nuclear merocyanine dye, 4-nuclear merocyanine dye, rhodacyanine dye, complex cyanine dye, complex merocyanine dye, allopolar dye, oxonol dye, hemioxonol dye, squalium dye, croconium dye, azamethine dye, coumarin dye, arylidene dye, anthraquinone dye , Triphenylmethane dye, azo dye, azomethine dye, spiro compound, metallocene dye, fluorenone dye, fulgide dye, perylene dye, perinone dye, phenazine dye, pheno Azine dye, quinone dye, diphenylmethane dye, polyene dye, acridine dye, acridinone dye, diphenylamine dye, quinacridone dye, quinophthalone dye, phenoxazine dye, phthaloperylene dye, diketopyrrolopyrrole dye, dioxane dye, porphyrin dye, chlorophyll dye, phthalocyanine And dyes, metal complex dyes, and condensed aromatic carbocyclic dyes (naphthalene derivatives, anthracene derivatives, phenanthrene derivatives, tetracene derivatives, pyrene derivatives, perylene derivatives, fluoranthene derivatives).

As the n-type organic semiconductor material, it is particularly preferable to use fullerene or a fullerene derivative having excellent electron transport properties. The fullerene, fullerene _{C 60,} fullerene _{C 70,} fullerene _{C 76,} fullerene _{C 78,} fullerene _{C 80,} fullerene _{C 82,} fullerene _{C 84,} fullerene _{C 90,} fullerene _{C 96,} fullerene _{C 240,} fullerene _{C 540,} mixed Fullerene and fullerene nanotube are represented, and a fullerene derivative represents a compound having a substituent added thereto.

  The substituent for the fullerene derivative is preferably an alkyl group, an aryl group, or a heterocyclic group. The alkyl group is more preferably an alkyl group having 1 to 12 carbon atoms, and the aryl group and the heterocyclic group are preferably benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring. , Biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran Ring, benzimidazole ring, imidazopyridine ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, phenanthridine ring, acridine ring, phenanthroli Ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, or phenazine ring, more preferably a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, pyridine ring, imidazole ring, oxazole ring, Or a thiazole ring, particularly preferably a benzene ring, a naphthalene ring, or a pyridine ring. These may further have a substituent, and the substituents may be bonded as much as possible to form a ring. In addition, you may have a some substituent and they may be the same or different. A plurality of substituents may be combined as much as possible to form a ring.

  When the photoelectric conversion layer contains fullerene or a fullerene derivative, electrons generated by photoelectric conversion can be quickly transported to the pixel electrode 34 or the counter electrode 38 via the fullerene molecule or fullerene derivative molecule. When fullerene molecules or fullerene derivative molecules are connected to form an electron path, the electron transport property is improved, and high-speed response of the photoelectric conversion element can be realized. For this purpose, the fullerene or fullerene derivative is preferably contained in the photoelectric conversion layer by 40% (volume ratio) or more. If there are too many fullerenes or fullerene derivatives, the p-type organic semiconductor will decrease, the junction interface will become smaller, and the exciton dissociation efficiency will decrease.

  When the triarylamine compound described in Japanese Patent No. 4213832 is used as a p-type organic semiconductor material mixed with fullerene or a fullerene derivative in the photoelectric conversion layer 52, a high SN ratio of the photoelectric conversion element can be expressed. Is particularly preferred. If the ratio of fullerene or fullerene derivative in the photoelectric conversion layer is too large, the amount of triarylamine compounds decreases and the amount of incident light absorbed decreases. As a result, the photoelectric conversion efficiency is reduced. Therefore, the fullerene or fullerene derivative contained in the photoelectric conversion layer preferably has a composition of 85% (volume ratio) or less.

  An electron donating organic material can be used for the electron blocking layer 50. Specifically, for low molecular weight materials, N, N′-bis (3-methylphenyl)-(1,1′-biphenyl) -4,4′-diamine (TPD) and 4,4′-bis [N Aromatic diamine compounds such as-(naphthyl) -N-phenyl-amino] biphenyl (α-NPD), oxazole, oxadiazole, triazole, imidazole, imidazolone, stilbene derivative, pyrazoline derivative, tetrahydroimidazole, polyarylalkane, butadiene 4,4 ′, 4 ″ -tris (N- (3-methylphenyl) N-phenylamino) triphenylamine (m-MTDATA), porphine, tetraphenylporphine copper, phthalocyanine, copper phthalocyanine, titanium phthalocyanine oxide, etc. Porphyrin compounds, triazole derivatives, Sadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, annealing amine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, silazane derivatives, carbazole derivatives, bifluorenes Derivatives and the like can be used, and as the polymer material, polymers such as phenylene vinylene, fluorene, carbazole, indole, pyrene, pyrrole, picoline, thiophene, acetylene, and diacetylene, and derivatives thereof can be used. It is possible to use any compound that has sufficient hole transport properties, even if it is not a functional compound.

  As the electron blocking layer 50, an inorganic material can also be used. In general, since an inorganic material has a dielectric constant larger than that of an organic material, when it is used for the electron blocking layer 50, a large voltage is applied to the photoelectric conversion layer, and the photoelectric conversion efficiency can be increased. Materials that can be used as the electron blocking layer 50 include calcium oxide, chromium oxide, chromium oxide copper, manganese oxide, cobalt oxide, nickel oxide, copper oxide, gallium copper oxide, strontium copper oxide, niobium oxide, molybdenum oxide, indium copper oxide, Examples include indium silver oxide and iridium oxide.

In the electron blocking layer composed of a plurality of layers, the layer adjacent to the photoelectric conversion layer 52 among the plurality of layers is preferably a layer made of the same material as the p-type organic semiconductor contained in the photoelectric conversion layer 52. Thus, by using the same p-type organic semiconductor for the electron blocking layer 50, it is possible to suppress the formation of intermediate levels at the interface between the photoelectric conversion layer 52 and the adjacent layer, and to further suppress the dark current. Can do.
When the electron blocking layer 50 is a single layer, the layer can be a layer made of an inorganic material, and when it is a plurality of layers, one or more layers can be a layer made of an inorganic material.

Next, a manufacturing method of the image sensor 20 will be described.
FIGS. 3A and 3B are schematic cross-sectional views illustrating the manufacturing method of the image sensor according to the embodiment of the present invention in the order of steps, and FIGS. 4A and 4B are diagrams of the embodiment of the present invention. It is typical sectional drawing which shows the manufacturing method of an image pick-up element in order of a process, and shows the post process of FIG.3 (b).
In the method of manufacturing the image sensor 20 according to the embodiment of the present invention, first, as shown in FIG. 3A, the first circuit is formed on the substrate 30 on which the readout circuit 60 and the counter electrode voltage supply unit 62 are formed. The insulating layer 32 provided with the connecting portion 64, the second connecting portion 66, and the wiring layer 68 is formed, and the pixel electrode 34 connected to each first connecting portion 64 is further formed on the surface 32a of the insulating layer 32. A formed circuit board 35 (CMOS substrate) is prepared. In this case, as described above, the first connection unit 64 and the readout circuit 60 are connected, and the second connection unit 66 and the counter electrode voltage supply unit 62 are connected. The pixel electrode 34 is made of, for example, TiN.

  Next, the electron blocking layer 50 is transferred to a film forming chamber (not shown) through a predetermined transfer path, and as shown in FIG. The electron blocking material is formed into a film under a predetermined vacuum using, for example, an evaporation method so as to cover 34, thereby forming the electron blocking layer 50. As the electron blocking material, for example, a carbazole derivative, more preferably a bifluorene derivative is used.

  Next, the photoelectric conversion layer 52 is transported to a film forming chamber (not shown) by a predetermined transport path, and the photoelectric conversion layer 52 is deposited on the surface 50a of the electron blocking layer 50 by a predetermined vacuum using, for example, a vapor deposition method. Form below. As the photoelectric conversion material, for example, a p-type organic semiconductor material and fullerene or a fullerene derivative are used. Thereby, the photoelectric conversion layer 52 is formed and the organic layer 36 is formed.

  Next, after transporting to a film forming chamber (not shown) of the counter electrode 38 through a predetermined transport path, the organic layer 36 (the photoelectric conversion layer 52 and the electron blocking layer 50) is covered, and the second connection portion 66 is covered. The counter electrode 38 is formed in a predetermined vacuum by using, for example, a sputtering method with the pattern formed in (1).

Next, the protective film 40 is transferred to a film forming chamber (not shown) through a predetermined transfer path, and as shown in FIG. 4A, the counter electrode 38 is covered so as to cover the surface 32a of the insulating layer 32. As the protective film 40, for example, a first silicon oxynitride layer 41a having a thickness of 100 nm and a second silicon oxynitride layer 41b having a thickness of 100 nm are stacked by an RF plasma CVD method.
In this case, as the protective film 40, a silicon oxynitride layer having the above composition and density is formed using a plasma CVD method at a substrate temperature (film formation temperature) of 245 ° C. or lower. As for the composition and density of the silicon oxynitride layer, the silicon oxynitride layer is formed in advance by changing the flow rate of the reaction gas, etc., and the film formation conditions (film formation temperature, pressure during film formation, high frequency power during film formation, By determining the gas type (SiH ₄ , NH ₃ , N ₂ O), gas mixing ratio, etc.), a silicon oxynitride layer within the above composition range can be formed.

In the formation of the protective film 40, as with the protective film 16, the first silicon oxynitride layer 41a is formed, and then the second silicon oxynitride layer 41b is changed by changing only the high-frequency power among the film forming conditions. Form. Thereby, the value of x of the second silicon oxynitride layer 41b can be made 0.05 or more larger than the value of x of the first silicon oxynitride layer 41a, and the composition can be changed. Moreover, the difference in refractive index can be within 0.1 and within 0.05.
In addition, the first silicon oxynitride layer 41a and the second silicon oxynitride layer 41b can be continuously formed by changing only the high frequency power among the film formation conditions without stopping the film formation gas.

  Next, as shown in FIG. 4B, the color filter 42, the partition wall 44, and the light shielding layer 46 are formed on the surface 40a of the protective film 40 by using, for example, a photolithography method. As the color filter 42, the partition wall 44, and the light shielding layer 46, known ones used for organic solid-state imaging devices are used. The formation process of the color filter 42, the partition wall 44, and the light shielding layer 46 may be under a predetermined vacuum or non-vacuum.

Next, an overcoat layer 48 is formed using, for example, a coating method so as to cover the color filter 42, the partition wall 44, and the surface 47 of the light shielding layer 46. Thereby, the image sensor 20 shown in FIG. 2 can be formed. As the overcoat layer 48, a known layer used for an organic solid-state imaging device is used. The overcoat layer 48 may be formed in a predetermined vacuum or non-vacuum.
When the overcoat layer 48 is formed of a multi-layered silicon oxynitride layer (SiOxNy layer), it can be formed by the same method as the protective film 40.

Hereinafter, other specific examples of the substrate with an organic functional layer will be described.
The board | substrate with an organic functional layer of this invention can also be called an organic solar cell and an organic EL element, for example.
Fig.5 (a) is typical sectional drawing which shows the organic solar cell of embodiment of this invention, (b) is typical sectional drawing which shows the organic EL element of embodiment of this invention.
An organic solar cell 70 shown in FIG. 5A has an organic photoelectric conversion layer 76. This organic photoelectric conversion layer 76 corresponds to the organic functional layer of the present invention, and the heat resistance is 245 ° C. or lower. The organic solar cell 70 is formed by laminating a lower electrode 74, an organic photoelectric conversion layer 76, a transparent electrode (upper electrode) 78, and a protective film 80 in this order on a substrate 72. Incident light L is incident from the transparent electrode 78 side.

The protective film 80 has the same two-layer structure as the protective film 16 described above, and has the same composition and density as the protective film 16. The protective film 80 is formed by the same manufacturing method as the protective film 16. For this reason, the detailed description is abbreviate | omitted. The board | substrate 72 is corresponded to the base material 12 (refer Fig.1 (a)) of this invention.
The protective film 80 is composed of a first silicon oxynitride layer 81a and a second silicon oxynitride layer 81b. The protective film 80 can be configured as shown in FIGS. 1B and 1C as well as the protective film 16.

The lower electrode 74, the organic photoelectric conversion layer 76, and the transparent electrode 78 are configured by general materials used for known organic solar cells. For this reason, the detailed description is abbreviate | omitted.
The current generated in the organic photoelectric conversion layer 76 by the irradiation of the incident light L is taken out by the lower electrode 74 and the transparent electrode 78.
Also in the organic solar cell 70 having such a configuration, the organic photoelectric conversion layer 76 can be protected over a long period of time in a high temperature and high humidity environment by providing the same protective film 80 as the protective film 16 described above. Thereby, durability of the organic solar cell 70 can be improved. Moreover, the protective film 80 is transparent as described above, and does not prevent the incident light L from entering the organic photoelectric conversion layer 76.

An organic EL element 70a shown in FIG. 5B is a light emitting element using the organic EL layer 86, and is called a top emission method. In addition, in the organic EL element 70a, the same code | symbol is attached | subjected to a structure similarly to the organic solar cell 70 shown to Fig.5 (a), and the detailed description is abbreviate | omitted.
The organic EL layer 86 corresponds to the organic functional layer of the present invention, and the heat resistance is 245 ° C. or lower. In the organic EL element 70a, a TFT 82, a cathode 84, an organic EL layer 86, a transparent electrode (upper electrode) 78, and a protective film 80 are laminated on a substrate 72 in this order. A power source 88 is connected to the TFT 82, the cathode 84 and the transparent electrode 78. The protective film 80 is the same as the organic solar cell 70 shown in FIG. 5A and has a two-layer structure. Even in this case, the protective film 80 can be configured as shown in FIGS.

The organic EL layer 86 is a portion that emits light, and is a layer in which a hole injection layer, a hole transport layer, a light emitting layer, an electron injection / transport layer, and the like are sequentially stacked.
The cathode 84 and the transparent electrode 78 are for applying a voltage necessary for causing the organic EL layer 86 to emit light, and the TFT 82 is for controlling the light emission of the organic EL element 70a.
The power supply 88 generates a voltage necessary for causing the organic EL layer 86 to emit light, and drives the TFT 82.
The TFT 82, the cathode 84, the organic EL layer 86, and the transparent electrode 78 are appropriately configured with general materials used for known organic EL elements. For this reason, the detailed description is abbreviate | omitted.

  Also in the organic EL element 70a having such a configuration, by providing the same protective film 80 as the above-described protective film 16, the organic EL layer 86 can be protected over a long period of time in a high temperature and high humidity environment. Thereby, durability of the organic EL element 70a can be improved. Moreover, the protective film 80 is transparent as described above, and does not affect the light emitted from the organic EL layer 86.

  The protective film of the present invention is not limited to any of the above-described examples, and the organic functional layer having a heat resistance of 245 ° C. or lower is protected over a long period of time in a high temperature and high humidity environment. It can be suitably used for those requiring transparency that does not hinder the incidence of light and the emission of light from the organic functional layer.

Hereinafter, the film stress of the protective film 16 and the protective film 40 and the measurement method thereof will be described. Since the protective film 16 and the protective film 40 have the same configuration, the protective film 16 will be described as an example. Note that the overcoat layer 48 can have the same configuration as the protective film 40. For this reason, the description of the following film stress and its measuring method includes the overcoat layer 48.
As shown in FIGS. 6A and 6B, the stress acting on the thin film 102 is described as the stress acting on the protective film 16 by taking the substrate 100 on which the thin film 102 corresponding to the protective film 16 is formed as an example. To do. The protective film 16 is a multilayer structure, and if the stress is measured using the multilayer structure as one film, the film stress of the protective film 16 can be obtained. The film stress of the protective film 16 can also be measured by measuring the stress of each silicon oxynitride layer of the protective film 16 in a single layer state and obtaining the average of the respective stresses.

FIG. 6A shows the direction of the compressive stress σ _c acting on the thin film 102 by an arrow when the substrate 100 on which the thin film 102 is formed is expanded. As illustrated in FIG. 6A, when the substrate 100 is warped so that the side on which the thin film 102 is formed protrudes, the thin film 102 formed on the substrate 100 expands, and the thin film 102 in close contact with the substrate 100. The force that tries to compress it works. This force is compressive stress sigma _c.

FIG. 6B shows the direction of the tensile stress σ _t acting on the thin film 102 by arrows when the substrate 100 on which the thin film 102 is formed is contracted. As shown in FIG. 6B, when the substrate 100 is warped so that the side on which the thin film 102 is formed is depressed, the thin film 102 formed on the substrate 100 contracts and the thin film 102 in close contact with the substrate 100 is formed. The force which tries to extend to works. This force is a tensile stress σ _t.

Here, the compressive stress σ _c and the tensile stress σ _t of the thin film 102 affect the amount of warpage of the substrate 100. Next, the stress can be measured using an optical lever method based on the warpage amount of the substrate 100.
FIG. 7 is a schematic diagram showing a measuring apparatus for measuring the amount of warpage of a substrate on which a thin film is formed. 7 includes a laser irradiation unit 202 that irradiates laser light, a splitter 204 that reflects part of light emitted from the laser irradiation unit 202 and transmits other light, and a splitter. And a mirror 206 for reflecting the light transmitted through 204. On one surface of the substrate 100, a thin film 102 which is an object to be measured is formed. The light reflected by the splitter 204 is irradiated onto the thin film 102 of the substrate 100, and the reflection angle of the light reflected by the surface of the thin film 102 at that time is detected by the first detection unit 208. The light reflected by the mirror 206 is applied to the thin film 102 of the substrate 100, and the reflection angle of the light reflected by the surface of the thin film 102 at that time is detected by the second detection unit 210.
FIG. 7 shows an example in which the compressive stress acting on the thin film 102 is measured by bending the substrate 100 so that the surface on which the thin film 102 is formed protrudes. Here, the thickness of the substrate 100 is h, and the thickness of the thin film 102 is t.

Next, a procedure for measuring the stress of the thin film by the measuring apparatus 200 will be described.
As an apparatus used for the measurement, for example, a thin film stress measuring apparatus FLX-2320-S manufactured by Toago Technology Co., Ltd. can be used. The measurement conditions when this apparatus is used are shown below.

(Laser light (laser irradiation unit 202))
Laser used: KLA-Tencor-2320-S
Laser power: 4mW
Laser wavelength: 670 nm
Scanning speed: 30mm / s

(substrate)
Substrate material: Silicon (Si)
Direction: <100>
Type: P type (Dopant: Boron)
Thickness: 250 ± 25 μm or 280 ± 25 μm

(Measurement procedure)
The amount of curvature of the substrate 100 on which the thin film 102 is formed is measured in advance, and the curvature radius R1 of the substrate 100 is obtained. Subsequently, the thin film 102 is formed on one surface of the substrate 100, the amount of warpage of the substrate 100 is measured, and the curvature radius R2 is obtained. Here, the amount of warpage is calculated from the reflection angle of the laser beam reflected from the substrate 100 by scanning the surface of the substrate 100 on which the thin film 102 is formed with a laser as shown in FIG. The radius of curvature R = R1 · R2 / (R1-R2) is calculated based on the amount of warpage.

  Thereafter, the stress of the thin film 102 is calculated by the following calculation formula. The unit of stress of the thin film 102 is represented by Pa. A negative value is indicated for compressive stress, and a positive value is indicated for tensile stress. Note that a method for measuring the stress of the thin film 102 is not particularly limited, and a known method can be used.

(Stress stress calculation formula)
^{σ = E × h 2/6} (1-ν) Rt
Where E / (1-ν): biaxial elastic modulus (Pa) of the underlying substrate, ν: Poisson's ratio h: thickness of the underlying substrate (m),
t: film thickness (m) of the thin film,
R: radius of curvature of base substrate (m),
σ: The average stress (Pa) of the thin film.

  The present invention is basically configured as described above. As mentioned above, although the board | substrate with an organic functional layer of this invention and its manufacturing method were demonstrated in detail, this invention is not limited to the said embodiment, In the range which does not deviate from the main point of this invention, various improvement or a change is carried out. Of course it is also good.

Hereinafter, the effect of the protective film of the present invention will be specifically described.
In this example, samples of Examples 1 and 2 and Comparative Examples 1 to 9 were prepared, and the effect of the protective film of the present invention was confirmed.

In this embodiment, as a sample, a pixel electrode is formed on a part of the surface of the base material on the base material, and an organic functional layer is formed on the base material as a photoelectric conversion layer so as to cover the pixel electrode. A photoelectric conversion element main body having a simplified structure in which a counter electrode is formed on the organic functional layer and a protective film covering the counter electrode is formed was used.
In addition, the thing of the 2 layer structure of the silicon oxynitride layer represented by SiOxNy was used for the protective film. Each silicon oxynitride layer The samples of Examples 1 and 2 and Comparative Examples 1 to 9 used the below-described element units having the same configuration except for the configuration of the protective film.

Hereinafter, the element unit will be described.
For each sample, an element unit formed as follows was prepared.
A non-alkali glass substrate having a thickness of 0.7 mm was prepared as a substrate, and an indium tin oxide (ITO) film having a thickness of 100 nm was formed as a pixel electrode on the substrate by a sputtering method.
Next, a material represented by the following chemical formula 1 was deposited as an electron blocking layer on the substrate so as to have a thickness of 100 nm at a deposition rate of 10 to 20 nm / s as an electron blocking layer so as to cover the image electrode. . Next, as an organic layer (photoelectric conversion layer), a material represented by the following chemical formula 2 (fullerene C ₆₀ ) and a material represented by the following chemical formula 3 are deposited at a deposition rate of 16 to 18 nm / s and 25 to 28 nm / s, respectively. Co-evaporated so that the volume ratio of the material shown in 2 and the material shown in chemical formula 3 below was 1: 3, and formed to a thickness of 400 nm.

Next, as a counter electrode, an indium tin oxide (ITO) film having a thickness of 10 nm was formed on the organic layer by sputtering to cover the organic layer.
Next, an aluminum oxide film (AlOx film) having a thickness of 30 nm was formed on the counter electrode by atomic layer chemical vapor deposition (AL-CVD).

The sample of Example 1 was produced as follows.
A silicon oxynitride layer (SiOxNy layer) having a thickness of 300 nm is formed as a protective film on the aluminum oxide film and the base material by plasma CVD so as to cover the counter electrode of the element unit thus prepared. Formed. Thus, the sample of Example 1 was produced.

The composition of the protective film of each sample of Examples 1 and 2 and Comparative Examples 1 to 9 is as shown in Table 1 below. It should be noted that the protective film is formed in advance so as to have a predetermined composition and density (film formation temperature (substrate temperature), pressure during film formation, high-frequency power during film formation, gas type (SiH ₄ , NH ₃ , N ₂ O) and gas mixing ratio, etc.) were determined, and a film was formed under the production conditions. The gas flow rate, deposition temperature, deposition pressure, and high frequency frequency during deposition were fixed, and only the high frequency power was changed to produce a protective film. A protective film for each sample was made separately. In Comparative Examples 4 and 5, the protective film of each sample was made separately by changing both the high frequency power and the film forming temperature.
In Examples 1 and 2 and Comparative Examples 1 to 9, the film formation temperature was 154 ° C. for those in which the film formation temperature was not specified in Table 1 below. Unless otherwise specified, the same gas type with a fixed component ratio of SiH ₄ , NH ₃ , and N ₂ O was used for film formation.
Further, the lower layer of Comparative Example 6 and the upper layer of Comparative Example 7 were formed by changing the film formation temperature to 350 ° C. and changing the gas type to gas type A. The lower layer of Comparative Example 8 and the upper layer of Comparative Example 9 were formed by changing the film formation temperature to 350 ° C. and changing the gas type to gas type B. The gas species A has a larger amount of NH ₃ among the above components than the gas species used for film formation unless otherwise specified. The gas type B has a larger amount of N ₂ O among the above components than the gas type used for film formation unless otherwise specified.

In this example, the film stress was measured for the protective films of the samples of Examples 1 and 2 and Comparative Examples 1 to 9, and the refractive index at a wavelength of 550 nm was measured using an ellipsometer. The results are shown in Table 1 below.
Further, the samples of Examples 1 and 2 and Comparative Examples 1 to 9 were left in an environment having a temperature of 85 ° C. and a relative humidity of 85%, and the dark current after being left in the above environment was not left in the above environment. The time required to reach twice the value was measured. This measurement time was defined as the life. The results are shown in Table 1 below.
The film stress was measured using the method shown in FIG.

The composition of the film was measured (XPS) as follows.
As a film composition measurement instrument, PHI Quantara SXM and a monochromatic Al-Kα ray of 15 kV-25 W as an X-ray source were used. The depth direction analysis was performed by Ar ⁺ etching / XPS. Regarding Ar ⁺ etching, the acceleration voltage of Ar ⁺ was 3 kV, and the etching area was 2 × 2 mm ² . Regarding XPS, the X-ray irradiation range and the analysis range were 300 × 300 μm ² , the pass energy was 112 eV, and the step was 0.2 eV. There was charging correction (both electron gun and low-speed ion gun), and each intensity of C1s, O1s, N1s, and Si2p was corrected with a sensitivity coefficient, and converted to an atomic ratio.

Regarding the dark current, an electric field of 2 × 10 ⁵ V / cm was applied to the counter electrode side in an environment of 60 ° C. with the photoelectric conversion element body shielded from light, and in this state, a source meter (Keithley 6430) The value of the current measured using was used as the dark current.
In Comparative Examples 6 to 9, when the protective film was formed, either the upper layer or the lower layer had a film formation temperature as high as 350 ° C., and the protective layer could be formed. The conversion layer has been damaged. Therefore, “NG” is described in the column of “85 ° C. 85% RH resistance (relative time)” in Table 1 below.

  As shown in Table 1 above, in Examples 1 and 2, the overall film stress of the protective film was 0 to −220 MPa, which was a region suitable as the film stress. In addition, even in an environment of a temperature of 85 ° C. and a relative humidity of 85%, the time until the dark current doubled is at least 1000 hours of Example 1, and the durability could be improved. In Examples 1 and 2, the composition of the upper layer and the lower layer could be changed by changing the high frequency power.

On the other hand, in Comparative Example 1, the upper layer and the lower layer of the protective film have the same composition, the total film stress of the protective film is +5 MPa and tensile stress acts, and the temperature is 85 ° C. and the relative humidity is 85% and the resistance is 100 hours. Low.
In Comparative Example 2, the upper layer and the lower layer of the protective film have the same composition, and the entire film stress of the protective film is −120 MPa and compressive stress is applied, but the temperature 85 ° C. and relative humidity 85% resistance is as low as 350 hours. .
In Comparative Example 3, the upper layer and the lower layer of the protective film have the same composition, and the entire film stress of the protective film is −280 MPa, and the compressive stress acts. A temperature of 85 ° C. and a relative humidity of 85% were 1000 hours.
In Comparative Example 4, the lower layer of the protective film exceeds the upper limit value of x. Further, in Comparative Example 4, in order to form the upper layer and the lower layer of the protective film, it is necessary to change the film formation temperature when forming the lower layer. For this reason, Comparative Example 4 cannot be manufactured by the manufacturing method of the present invention.

In Comparative Example 5, the lower layer of the protective film satisfies the value of x and the formula of y, and the upper layer exceeds the upper limit of the value of x. For this reason, barrier property became low and the temperature 85 degreeC relative humidity 85% tolerance was 10 hours.
In Comparative Examples 6 to 9, although the film forming temperature was as high as 350 ° C. and the protective film could be formed as described above, the organic layer (photoelectric conversion layer) was damaged.
Moreover, since the comparative examples 6 and 7 both have a refractive index difference of 0.12, which exceeds the range of the present invention, reflection of incident light cannot be suppressed, the reflectance increases, and the photoelectric conversion element The sensitivity of the main unit has decreased.
In Comparative Example 8, the lower layer does not satisfy the equation of y, and the upper layer satisfies the value of x and the equation of y. In Comparative Example 8, the film stress of the entire protective film is as large as -350 MPa, and film peeling occurs.
In Comparative Example 9, the lower layer satisfies the value of x and the equation of y, and the upper layer does not satisfy the equation of y. In Comparative Example 9, the film stress of the entire protective film is as large as -350 MPa, and film peeling occurs.

DESCRIPTION OF SYMBOLS 10 Substrate with organic layer 12 Base material 14 Organic functional layer 16, 40, 80 Protective film 16a, 41a, 81a First silicon oxynitride layer 16b, 41b, 81b Second silicon oxynitride layer 20 Imaging element 30 Substrate 32 Insulation Layer 34 Pixel electrode (lower electrode)
36 organic layer 48 overcoat layer 50 electron blocking layer 52 photoelectric conversion layer 70 organic solar cell 70a organic EL element

Claims (7)

A substrate;
An organic functional layer having a heat resistance of 245 ° C. or less disposed on the substrate;
A protective film disposed on the organic functional layer,
The protective film has a plurality of silicon oxynitride layers represented by SiOxNy, and each silicon oxynitride layer has a refractive index difference of 0.1 or less in absolute value,
X and y satisfy 0.5 ≦ x ≦ 1.0 and −2.2y + 2.1 ≦ x ≦ −2.2y + 2.41;
In the protective film, among the plurality of silicon oxynitride layers, a silicon oxynitride layer far from the organic functional layer is a silicon oxynitride layer formed at a position where the value of x is closest to the organic functional layer A substrate with an organic functional layer, which is 0.05 or more larger than the value of x.   The substrate with an organic functional layer according to claim 1, wherein the protective film has a total thickness of 50 nm or more.   The substrate with an organic functional layer according to claim 1, wherein the protective film has another layer between each silicon oxynitride layer. The organic functional layer is an organic photoelectric conversion layer that generates charges when irradiated with light,
The organic photoelectric conversion layer is provided with a lower electrode on the substrate side and a transparent upper electrode on the opposite side of the substrate,
The substrate with an organic functional layer according to claim 1, wherein the protective film is disposed on the upper electrode. The organic functional layer is a color filter layer containing an organic substance,
The substrate with an organic functional layer according to claim 1, wherein the protective film is disposed on the color filter layer.   6. The organic functional layer according to claim 1, wherein x and y satisfy 0.5 ≦ x ≦ 1.0 and −2.2y + 2.1 ≦ x ≦ −2.2y + 2.32. substrate. A protective film forming step of forming a plurality of silicon oxynitride layers represented by SiOxNy as a protective film on the organic functional layer having a heat resistance of 245 ° C. or less disposed on the substrate by using a plasma CVD method; And
In the protective film forming step, only the high frequency power is changed among the film forming conditions in the plasma CVD method, and the silicon oxynitride layer far from the organic functional layer is set, and the value of x is closest to the organic functional layer. A method for producing a substrate with an organic functional layer, characterized in that the silicon oxynitride layer formed at a position is formed with a composition larger than 0.05 by the value of x.