Photoelectric conversion devices and equipment

Abstract

To provide a photoelectric conversion device that reduces dark current.SOLUTION: A photoelectric conversion device 930 has a semiconductor layer 100 that has a plurality of photoelectric conversion parts 101, 102, 103, and has a first surface (rear face 1001) and a second surface (front face 1002). The photoelectric conversion device 930 comprises a wiring structure 440 that is arranged on the second surface of the semiconductor layer 100, and a metal compound film 200 arranged on the first surface of the semiconductor layer 100. The metal compound film 200 contains hydrogen and carbon. The concentration of hydrogen in an interface of the metal compound film 200 facing the semiconductor layer 100 is 1×1021 atoms / cm3 or more and 1×1022 atoms / cm3 or less. The concentration of carbon in the interface of the metal compound film 200 facing the semiconductor layer 100 is 5×1020 atoms / cm3 or more and 1×1022 atoms / cm3 or less.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a photoelectric conversion device and an apparatus. [Background technology]

[0002] A photoelectric conversion element has been proposed in which a protective film made of aluminum oxide is provided on a silicon substrate having a photoelectric conversion layer. Patent Document 1 describes that by making the protective film on the silicon substrate contain hydrogen, dangling bonds (unbonded hands) existing near the interface of the silicon substrate are easily terminated, thereby suppressing recombination of carriers at the interface of the silicon substrate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 115275 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes adjusting the concentration of hydrogen contained in a protective film made of aluminum oxide provided on a silicon substrate. However, the dark current is not sufficiently suppressed by only adjusting the concentration of hydrogen.

[0005] In view of the above-mentioned problems, an object of the present invention is to provide a photoelectric conversion device in which dark current is suppressed. [Means for solving the problem]

[0006] A photoelectric conversion device according to one aspect of the present invention is a photoelectric conversion device including: a semiconductor layer having a plurality of photoelectric conversion units, the semiconductor layer having a first surface and a second surface that is a surface opposite to the first surface; a wiring structure disposed on the second surface side of the semiconductor layer; and a metal compound film disposed on the first surface side of the semiconductor layer, the metal compound film containing hydrogen and carbon, and a concentration of the hydrogen at an interface of the metal compound film on the semiconductor layer side being 1×10 21 atoms / cm 3 More than 1×10 22 atoms / cm 3 The carbon concentration at the interface on the semiconductor layer side of the metal compound film is 5×10 20 atoms / cm 3 More than 1×10 22 atoms / cm 3 The present invention is characterized in that: Effect of the Invention

[0007] According to the present invention, it is possible to provide a photoelectric conversion device in which dark current is suppressed. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating a photoelectric conversion device. [Diagram 2] 4 is a graph showing the relationship between hydrogen concentration and carbon concentration and dark current, for explaining a photoelectric conversion device. [Diagram 3] 1 is a graph showing the relationship between the ratio of hydrogen concentration to carbon concentration and dark current, for explaining a photoelectric conversion device. [Figure 4] FIG. 1 is a schematic diagram illustrating an apparatus including a photoelectric conversion device. [Diagram 5] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a photoelectric conversion device. [Figure 6] 5A to 5C are schematic cross-sectional views illustrating a method for manufacturing a photoelectric conversion device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the embodiment of the present invention will be described with reference to the drawings. In the following description and drawings, common symbols are used for configurations common to multiple drawings. Therefore, common configurations will be described with mutual reference to multiple drawings, and configurations with common symbols will not be described as appropriate. Configurations with similar names and different symbols may be distinguished from each other by adding "first configuration", "second configuration", "third configuration", etc., as appropriate. In addition, in this specification, the description "XX or more and XX or less" or "XX to XX" representing a numerical range means a numerical range including the lower limit and upper limit, which are the endpoints, unless otherwise specified.

[0010] [Configuration of photoelectric conversion device] 1 is a cross-sectional view of a photoelectric conversion area (imaging area) of a photoelectric conversion device 930 according to this embodiment. The photoelectric conversion device 930 includes a semiconductor layer 100 having a plurality of photoelectric conversion sections 101, 102, and 103.

[0011] The semiconductor layer 100 is a single crystal silicon layer having a thickness of, for example, 1 μm to 10 μm, preferably 2 μm to 5 μm. The semiconductor layer 100 has a back surface 1001 that forms a light receiving surface (light incident surface) of each of the multiple photoelectric conversion units 101, 102, and 103. Each of the multiple photoelectric conversion units 101, 102, and 103 can be a photodiode.

[0012] The back surface 1001 is one of the two main surfaces of the semiconductor layer 100, and the semiconductor layer 100 has a front surface 1002 which is the other of the two main surfaces of the semiconductor layer 100. Hereinafter, the back surface 1001 may be referred to as the first surface, and the front surface 1002 may be referred to as the second surface. A transistor including a gate electrode 400 is provided on the front surface 1002, and a wiring structure 440 including a plurality of wiring layers 410, 420 and an interlayer insulating film 430 is provided on the front surface 1002. That is, the wiring structure 440 is provided on the second surface side of the semiconductor layer 100. The transistor including the gate electrode 400 includes a transfer transistor, an amplification transistor, a reset transistor, a selection transistor, etc., and these transistors form a pixel circuit.

[0013] A silicon compound film 300, which is a compound of silicon and at least one of oxygen, nitrogen, and carbon, such as a silicon oxide film, a silicon nitride film, or a silicon carbide film, is provided on the light receiving surfaces of the photoelectric conversion units 101, 102, and 103. The composition of the silicon compound film 300 is SiO x N y C z Here, any one of x, y, and z is greater than 0, and any other of x, y, and z greater than 0 may or may not be 0. The silicon compound film can contain hydrogen (H), boron (B), fluorine (F), phosphorus (P), chlorine (Cl), argon (Ar), and the like, in addition to silicon (Si), oxygen (O), nitrogen (N), and carbon (C). When x>0, x≧y≧0, and x≧z≧0, the silicon compound film 300 is a silicon oxide film. When y>0, y≧x≧0, and y≧z≧0, the silicon compound film 300 is a silicon nitride film. When z>0, z≧x≧0, and z≧y≧0, the silicon compound film 300 is a silicon carbide film. For example, a SiON film can be classified into a silicon oxide film or a silicon nitride film depending on the amount of O and N.

[0014] Furthermore, on the light receiving surfaces of the photoelectric conversion units 101, 102, and 103, an insulating layer 150 and a metal compound film 200 are laminated in this order from the light receiving surface side. In other words, the insulating layer 150 and the metal compound film 200 are disposed on the first surface side of the semiconductor layer 100. In this embodiment, the insulating layer 150 and the metal compound film 200 are disposed between the silicon compound film 300 and the semiconductor layer 100. Details of the metal compound film 200 will be described later. In this embodiment, the insulating layer 150 is disposed between the semiconductor layer 100 and the metal compound film 200, but this is not limited thereto, and the metal compound film 200 may be disposed directly on the semiconductor layer 100 without disposing the insulating layer 150. In other words, the metal compound film 200 may be disposed on the semiconductor layer 100 so as to be in contact with the semiconductor layer 100.

[0015] The insulating layer 150 is disposed on the first surface side of the photoelectric conversion units 101, 102, and 103. The insulating layer 150 may have a function of lowering the interface state, and therefore may also be referred to as a layer that lowers the interface state. The insulating layer 150 may be formed by oxidizing the back surface 1001 of the semiconductor layer 100, and is made of silicon oxide (SiO2) in this embodiment. As described later, the metal compound film 200 can be formed by atomic layer deposition (ALD). The insulating layer 150 can also be formed secondarily on the back surface 1001 of the semiconductor layer 100 when the metal compound film 200 is formed by the ALD method. The thickness of the insulating layer 150 is not particularly limited, but may be 1 atomic layer or more and 50 nm or less, preferably 0.1 nm or more and 10 nm or less, more preferably 0.2 nm or more and 5 nm or less, and particularly preferably 0.3 nm or more and 2 nm or less. By setting the thickness of the insulating layer 150 to 10 nm or less, preferably 1 nm or less, the insulating layer 150 is easily permeable to hydrogen contained in the metal compound film 200. This is preferable because even if the insulating layer 150 is formed between the semiconductor layer 100 and the metal compound film 200, the terminating effect of the dangling bonds at the interface of the semiconductor layer 100 due to hydrogen contained in the metal compound film 200 is not easily reduced.

[0016] A microlens array including a plurality of microlenses 871, 872, and 873 is provided on the back surface 1001. One microlens 871 of the plurality of microlenses 871, 872, and 873 is disposed on the photoelectric conversion unit 101. One microlens 872 of the plurality of microlenses 871, 872, and 873 is disposed on the photoelectric conversion unit 102. One microlens 873 of the plurality of microlenses 871, 872, and 873 is disposed on the photoelectric conversion unit 103. In a plan view from a direction perpendicular to the back surface 1001, it can be said that the microlens 871 overlaps with the photoelectric conversion unit 101, the microlens 872 overlaps with the photoelectric conversion unit 102, and the microlens 873 overlaps with the photoelectric conversion unit 103. Each of the plurality of microlenses 871, 872, and 873 is made of, for example, resin.

[0017] Between the microlens array including the plurality of microlenses 871, 872, 873 and the semiconductor layer 100, another intralayer lens array including a plurality of intralayer lenses 831, 832, 833 is provided. Each of the plurality of intralayer lenses 831, 832, 833 is provided in a dielectric film 820 such as a silicon nitride film. In this example, the intralayer lenses 831, 832, 833 are upwardly convex lenses, but may be downwardly convex lenses or biconvex lenses.

[0018] An insulator film 810 such as a silicon oxide film is provided between the inner-layer lenses 831, 832, 833 and the silicon compound film 300. An insulator film 840 such as a silicon oxide film is provided between the inner-layer lenses 831, 832, 833 and the microlenses 871, 872, 873. The inner-layer lenses 831, 832, 833 focus light due to the refractive index difference between the insulator film 840 and the inner-layer lenses 831, 832, 833 made of silicon nitride. A color filter array including color filters 861, 862, 863 is provided between the inner-layer lenses 831, 832, 833 and the microlenses 871, 872, 873. It can also be said that, in a plan view from a direction perpendicular to the rear surface 1001, the color filter 861 overlaps with the photoelectric conversion section 101, the color filter 862 overlaps with the photoelectric conversion section 102, and the color filter 863 overlaps with the photoelectric conversion section 103. For example, the color filter 861 is a red filter, the color filter 862 is a green filter, and the color filter 863 is a blue filter. A planarization film 850 is provided between the color filters 861, 862, 863 and the inner-layer lenses 831, 832, 833, and / or between the color filters 861, 862, 863 and the microlenses 871, 872, 873. The planarization film 850 is made of, for example, a resin.

[0019] A light-shielding member 710 is provided between an insulator film 810 such as a silicon oxide film and the silicon compound film 300. A light-shielding wall 720 is provided on the light-shielding member 710. The light-shielding wall 720 can be provided so as to penetrate at least one of the insulator film 810, the dielectric film 820, and the insulator film 840. The light-shielding wall 720 can be disposed so as to surround the intralayer lenses 831, 832, and 833.

[0020] The optical structure of one pixel is mainly defined by a microlens, a color filter, an inner-layer lens, and a photoelectric conversion unit. For example, the optical structure of a pixel having a photoelectric conversion unit 102 is defined by a microlens 872, a color filter 862, an inner-layer lens 832, and the photoelectric conversion unit 102. However, some of the microlenses, color filters, and inner-layer lenses may be omitted.

[0021] A semiconductor substrate 600 is laminated on the semiconductor layer 100. A transistor including a gate electrode 500 is provided on the surface of the semiconductor substrate 600. A wiring structure 540 is provided on the surface of the semiconductor substrate 600 (between the semiconductor substrate 600 and the wiring structure 440). The wiring structure 540 is composed of a plurality of wiring layers 510, 520 and an interlayer insulating film 530. The transistor including the gate electrode 500 constitutes a driving circuit for driving a pixel circuit including a photoelectric conversion unit, and a control circuit for controlling the photoelectric conversion device 930. In addition, the transistor including the gate electrode 500 constitutes an AD conversion circuit that performs analog-to-digital (AD) conversion of an analog signal obtained from the pixel circuit. In addition, the transistor including the gate electrode 500 constitutes a digital signal processing circuit that processes a digital signal obtained by AD conversion. The electrical connection between the wiring structure 440 and the wiring structure 540 is made by wiring by direct bonding of the wiring layers or a through via that penetrates the semiconductor layer 100. The electrical connection between the wiring structure 440 and the wiring structure 540 may be made by a bump between the wiring structure 440 and the wiring structure 540 or may be made by wire bonding. When the semiconductor substrate 600 is used simply as a support substrate, the transistor including the gate electrode 500 and the wiring structure 540 can be omitted.

[0022] <Metal compound layer> The metal compound film 200 is a single-layer film or a multi-layer film of a metal compound layer. The metal compound layer constituting the metal compound film 200 is any one of a metal oxide layer, a metal nitride layer, and a metal carbide layer. Among them, the metal compound layer is preferably a metal oxide layer because of its high light transmittance. Specific examples of materials constituting the metal compound layer include oxides, nitrides, and carbides containing at least one element selected from hafnium (Hf), aluminum (Al), zirconium (Zr), tantalum (Ta), and titanium (Ti). Materials constituting the metal compound layer include MO. l N m C n Here, any one of l, m, and n is greater than 0, and any other of l, m, and n that is greater than 0 may or may not be 0. Among these, it is preferable that l is greater than 0. M may be any one of hafnium (Hf), aluminum (Al), zirconium (Zr), tantalum (Ta), and titanium (Ti). In addition to the above, specific materials constituting the metal compound layer include oxides, nitrides, or carbides containing at least one element selected from lanthanum (La), praseodymium (Pr), cerium (Ce), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y). The metal compound layer preferably has at least one layer selected from the group consisting of a hafnium oxide layer, a zirconium oxide layer, an aluminum oxide layer, a titanium oxide layer, and a tantalum oxide layer.

[0023] The metal compound film 200 preferably includes a layer having a negative fixed charge. In other words, the metal compound film 200 is preferably a fixed charge film having a negative fixed charge. When the metal compound film 200 is composed of a plurality of metal compound layers, the metal compound layer closest to the semiconductor layer 100 among the plurality of metal compound layers is preferably a layer having a negative fixed charge. Since the metal compound film 200 has a negative fixed charge, an inversion layer is formed on the back surface 1001 side of the semiconductor layer 100 (the side of the surface in contact with the metal compound film 200). As a result, the interface of the semiconductor layer 100 is pinned by the inversion layer, and the generation of dark current is suppressed.

[0024] By making the composition of metal and oxygen in the metal oxide layer deviate from the stoichiometric ratio, the metal oxide layer can have a fixed charge. By making the composition have less metal or more oxygen than the stoichiometric ratio, the metal oxide layer can have a negative fixed charge. For example, when aluminum oxide is used as the metal oxide layer closest to the semiconductor layer 100 among the layers constituting the metal compound film 200, it is preferable to make the composition have less aluminum or more oxygen than the stoichiometric ratio.

[0025] The metal compound film 200 of this example is a laminated film including, from the side closer to the semiconductor layer 100, a first metal compound layer 210 and a second metal compound layer 220. The thickness of the metal compound film 200 is the sum of the thickness of the first metal compound layer 210 and the thickness of the second metal compound layer 220. It is preferable that the thickness of the first metal compound layer 210 is smaller than the thickness of the second metal compound layer 220.

[0026] The first metal compound layer 210 preferably has a negative fixed charge as described above, and can function as a charge fixing layer for fixing non-signal charges of the semiconductor layer 100. The second metal compound layer 220 can function as an anti-reflection layer for light incident on the semiconductor layer 100. The first metal compound layer 210 is the layer closest to the semiconductor layer 100 among the multiple layers constituting the metal compound film 200. The first metal compound layer 210 is preferably any one of a hafnium oxide layer, a zirconium oxide layer, an aluminum oxide layer, a titanium oxide layer, and a tantalum oxide layer, and is particularly preferably an aluminum oxide layer. The second metal compound layer 220 is preferably any one of a hafnium oxide layer, a zirconium oxide layer, an aluminum oxide layer, a titanium oxide layer, and a tantalum oxide layer, and is particularly preferably a hafnium oxide layer or a tantalum oxide layer.

[0027] When the semiconductor layer 100 is a silicon layer and photoelectric conversion is performed on visible light, the metal compound film 200 is preferably configured as follows. That is, the first metal compound layer 210 is, for example, an aluminum oxide (Al2O3) layer having a thickness of 5 nm to 20 nm, and the second metal compound layer 220 is, for example, a tantalum oxide (Ta2O5) layer having a thickness of 25 nm to 100 nm. Furthermore, an insulating layer 150 is disposed between the semiconductor layer 100 and the first metal compound layer 210, and the insulating layer 150 is preferably, for example, a silicon oxide (SiO2) layer having a thickness of 0.1 nm to 5 nm.

[0028] In this embodiment, a back-illuminated photoelectric conversion device in which the back surface 1001 forms the light receiving surface has been described, but the present invention is also applicable to a front-illuminated photoelectric conversion device in which the front surface 1002 forms the light receiving surface. Also, in this embodiment, a CMOS (Complementary Metal Oxide Semiconductor) image sensor has been described as the photoelectric conversion device, but the present invention is not limited to this. As the photoelectric conversion device, any sensor such as a CCD (Charge Coupled Device) image sensor can also be used.

[0029] <Hydrogen and carbon concentrations in the metal compound layer> The metal compound film 200 contains hydrogen and carbon. In this embodiment, the first metal compound layer 210 contains hydrogen and carbon. In this embodiment, the first metal compound layer 210 is made of aluminum oxide and has a negative fixed charge.

[0030] (Hydrogen concentration) Since first metal compound layer 210 contains hydrogen, dangling bonds of materials constituting semiconductor layer 100 that may be present at the interface with back surface 1001 of semiconductor layer 100 are terminated. Terminating the dangling bonds suppresses recombination of carriers at back surface 1001 of semiconductor layer 100, and as a result, dark current is suppressed. Even if another layer such as insulating layer 150 is interposed between first metal compound layer 210 and semiconductor substrate 100, hydrogen can permeate the other layer and terminate the dangling bonds as long as the other layer is sufficiently thin.

[0031] Therefore, from the viewpoint of terminating dangling bonds at the interface of the back surface 1001 of the semiconductor layer 100 and suppressing dark current, it is preferable that the concentration of hydrogen contained in the first metal compound layer 210 is relatively high. In particular, hydrogen present at the interface of the first metal compound layer 210 closer to the semiconductor layer 100 (i.e., the interface on the semiconductor layer side) contributes greatly to terminating dangling bonds, so it is preferable that the hydrogen concentration at the interface closer to the semiconductor layer 100 is high. Specifically, the hydrogen concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side is 1×10 21 atoms / cm 3 More preferably, it is equal to or greater than this.

[0032] On the other hand, if the first metal compound layer 210 contains an excessive amount of hydrogen, there may be a large amount of free hydrogen that does not contribute to the termination of the dangling bonds of the semiconductor layer 100 and is not bonded to the metal compounds that constitute the first metal compound layer 210. Such hydrogen is converted into hydrogen ions (H +) is considered to be present. If a large amount of hydrogen ions are present in the first metal compound layer 210, the negative fixed charge possessed by the first metal compound layer 210 will decrease, and the effect of suppressing dark current may decrease. For this reason, it is preferable that the concentration of hydrogen contained in the first metal compound layer 210 is relatively low. In particular, if hydrogen ions are present at the interface of the first metal compound layer 210 closer to the semiconductor layer 100, the negative fixed charge is more likely to decrease, so it is preferable that the hydrogen concentration at the interface closer to the semiconductor layer 100 is low. Specifically, the hydrogen concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side is 1×10 22 atoms / cm 3 The hydrogen concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side is preferably 5×10 21 atoms / cm 3 More preferably, it is 3×10 21 atoms / cm 3 It is even more preferable that it is less than 1000 .mu.m.

[0033] In summary, the hydrogen concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side is 1×10 21 atoms / cm 3 More than 1×10 22 atoms / cm 3 The hydrogen concentration is preferably 1×10 21 atoms / cm 3 5×10 or more 21 atoms / cm 3 More preferably, it is 1×10 21 atoms / cm 3 More than 3×10 21 atoms / cm 3 It is preferable that the hydrogen concentration is within the above-mentioned range because dark current can be suppressed by setting the hydrogen concentration within the above-mentioned range.

[0034] The hydrogen concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side may be the hydrogen concentration in a region with a height of 0 nm to 3 nm, with the interface of the first metal compound layer 210 on the semiconductor layer 100 side being set as a reference height (0 nm). Here, the direction from the semiconductor layer 100 toward the first metal compound layer 210 is defined as the positive direction.

[0035] The first metal compound layer 210 may have a non-uniform hydrogen concentration distribution in the thickness direction. In other words, the first metal compound layer 210 may have a hydrogen concentration that varies along the thickness direction. That is, the hydrogen concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side may be different from the hydrogen concentration in a portion of the first metal compound layer 210 away from the interface on the semiconductor layer 100 side. In the following description, the former hydrogen concentration is referred to as the interface hydrogen concentration, and the latter hydrogen concentration is referred to as the in-film hydrogen concentration. The in-film hydrogen concentration may be the hydrogen concentration in a region of the first metal compound layer 210 that is 3 nm or more away from the interface on the semiconductor layer 100 side.

[0036] The hydrogen concentration in the film is preferably lower than the hydrogen concentration at the interface. When the hydrogen concentration is low, the crystallinity of the first metal compound layer 210 can be increased. This increases the mechanical strength and improves the moisture resistance. The hydrogen concentration of the first metal compound layer 210 preferably monotonically decreases with increasing distance from the interface on the semiconductor layer 100 side in a region between the interface on the semiconductor layer 100 side and a surface 3 nm away from the interface on the opposite side to the semiconductor layer 100. In this way, it is possible to achieve both suppression of dark current by terminating dangling bonds at the interface of the semiconductor layer 100 and high moisture resistance and high mechanical strength of the first metal compound layer 210. The hydrogen concentration in the film of the first metal compound layer 210 is 5×10 20 atoms / cm 3 More than 2×10 21 atoms / cm 3 It is preferable that the concentration of hydrogen and carbon in the metal compound film 200 such as the first metal compound layer 210 can be adjusted by the film formation atmosphere, the film formation temperature, and the heat treatment conditions after film formation.

[0037] 2 shows graphs representing the relationship between the hydrogen concentration and the average value of the dark current in the first metal compound layer 210, and the relationship between the carbon concentration and the average value of the dark current, when the semiconductor layer 100 is made of silicon and the first metal compound layer 210 is made of aluminum oxide. FIG. 2(a) shows the relationship between the interfacial hydrogen concentration and the average value of the dark current, and FIG. 2(b) shows the relationship between the in-film hydrogen concentration and the average value of the dark current. As shown in FIG. 2(a), the dark current tends to be suppressed as the interfacial hydrogen concentration increases. Furthermore, when the interfacial hydrogen concentration is 1×10 21 atoms / cm 3 More than 1×10 22 atoms / cm 3 When the hydrogen concentration in the film is 5×10 or less, the dark current is low. As shown in FIG. 2(b), the dark current tends to be suppressed as the hydrogen concentration in the film increases. 20 atoms / cm 3 More than 2×10 21 atoms / cm 3 The dark current has a low value when the semiconductor layer 100 is made of silicon and the first metal compound layer 210 is made of aluminum oxide.

[0038] (carbon concentration) As described above, if the first metal compound layer 210 contains an excessive amount of hydrogen, a large amount of free hydrogen may be present in the first metal compound layer 210. Such free hydrogen may reduce the effect of suppressing dark current. Therefore, in this embodiment, the first metal compound layer 210 contains carbon. The carbon contained in the first metal compound layer 210 may exist in a state of being bonded to a metal element, as expressed by M-CH2- or MCO-, where M is a metal element. As described later, the first metal compound layer 210 may be formed by a film formation method using an organic metal as a raw material, such as an ALD method or a metal organic chemical vapor deposition (MOCVD) method. In particular, when the film is formed by these film formation methods, the carbon is likely to exist in a state of being bonded to a metal element in the above-mentioned form. By containing a certain amount of carbon in the first metal compound layer 210, even if there is a large amount of hydrogen that contains a large amount of hydrogen and does not contribute to the termination of dangling bonds at the interface of the semiconductor layer 100, such hydrogen is captured by the carbon. This makes it possible to suppress the liberation of hydrogen within the first metal compound layer 210 and the reduction in the negative fixed charges.

[0039] On the other hand, when the first metal compound layer 210 contains carbon, the refractive index of the first metal compound layer 210 is lowered. The carbon concentration of the first metal compound layer 210 and the refractive index of the first metal compound layer 210 are inversely proportional to each other, and the higher the carbon concentration of the first metal compound layer 210, the lower the refractive index of the first metal compound layer 210. In general, the semiconductor layer 100 has a high refractive index, and the refractive index of the semiconductor layer 100 is higher than that of the first metal compound layer 210. If the refractive index of the first metal compound layer 210 becomes too low, the difference in refractive index between the first metal compound layer 210 and the semiconductor layer 100 becomes large, and the reflectance between the first metal compound layer 210 and the semiconductor layer 100 becomes large. Therefore, from the viewpoint of the efficiency of incidence of light into the semiconductor layer 100, it is preferable that the refractive index of the first metal compound layer 210 is not too low, and therefore, it is preferable that the carbon concentration of the first metal compound layer 210 is low to a certain extent. Note that even when insulating layer 150 is disposed between semiconductor layer 100 and first metal compound layer 210, if insulating layer 150 is sufficiently thin, the effect of insulating layer 150 on the reflection of light between semiconductor layer 100 and first metal compound layer 210 can be ignored. For example, if insulating layer 150 has a thickness of 50 nm or less, the reflection of light between semiconductor layer 100 and first metal compound layer 210 can be governed by the refractive index of semiconductor layer 100 and the refractive index of first metal compound layer 210.

[0040] From the above, the carbon concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side is 5×10 20 atoms / cm 3 More than 1×10 22 atoms / cm 3 The carbon concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side is preferably 1×10 21 atoms / cm 3 More preferably, it is 2×10 21 atoms / cm 3 It is more preferable that the carbon concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side is 5×10 20 atoms / cm 3By setting the carbon concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side to 1×10 or more, it is possible to suppress the liberation of hydrogen and enhance the effect of suppressing dark current. 22 atoms / cm 3 The above makes it possible to suppress deterioration in the crystallinity of the first metal compound layer 210. As with the interfacial hydrogen concentration, the carbon concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side may be defined as the carbon concentration in a region with a height of 0 nm to 3 nm, with the interface of the first metal compound layer 210 on the semiconductor layer 100 side being set as the reference height (0 nm).

[0041] The first metal compound layer 210 may have a non-uniform carbon concentration distribution in the thickness direction. In other words, the first metal compound layer 210 may have a carbon concentration that varies along the thickness direction. That is, the carbon concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side may be different from the carbon concentration at a portion of the first metal compound layer 210 away from the interface on the semiconductor layer 100 side. In the following description, the former carbon concentration is referred to as the interface carbon concentration, and the latter carbon concentration is referred to as the in-film carbon concentration, as in the case of the hydrogen concentration. The in-film carbon concentration may be the carbon concentration in a region of the first metal compound layer 210 that is 3 nm or more away from the interface on the semiconductor layer 100 side.

[0042] The carbon concentration in the first metal compound layer 210 is 1×10 19 atoms / cm 3 More than 1×10 21 atoms / cm 3 It is preferable that:

[0043] Fig. 2(c) shows the relationship between the interface carbon concentration and the average dark current, and Fig. 2(d) shows the relationship between the carbon concentration in the film and the average dark current. As shown in Fig. 2(c), the dark current tends to be suppressed as the interface carbon concentration increases. 20 atoms / cm 3 More than 1×10 22 atoms / cm 3When the carbon concentration in the film is 1×10 or less, the dark current is low. As shown in FIG. 2(d), the dark current tends to be suppressed as the carbon concentration in the film increases. 19 atoms / cm 3 More than 1×10 21 atoms / cm 3 The dark current has a low value when the semiconductor layer 100 is made of silicon and the first metal compound layer 210 is made of aluminum oxide.

[0044] (Ratio of hydrogen concentration to carbon concentration) As described above, carbon contained in the first metal compound layer 210 has the function of capturing excess hydrogen in the first metal compound layer 210, and therefore the ratio of the carbon concentration to the hydrogen concentration in the first metal compound layer 210 is also important from the viewpoint of suppressing dark current. By setting the ratio of the hydrogen concentration to the carbon concentration in the first metal compound layer 210 to an appropriate value, it is possible to suppress a decrease in the refractive index of the first metal compound layer 210 while suppressing dark current by exerting the hydrogen capturing effect of carbon. Hereinafter, the ratio of the hydrogen concentration to the carbon concentration in the first metal compound layer 210 (hydrogen concentration / carbon concentration) will be considered.

[0045] If the hydrogen concentration / carbon concentration is too high, the excess hydrogen that does not contribute to the termination of the dangling bonds at the interface of the semiconductor layer 100 cannot be captured by carbon, and free hydrogen is likely to be generated in the first metal compound layer 210. As a result, as described above, the negative fixed charge possessed by the first metal compound layer 210 is reduced, and the effect of suppressing the dark current is reduced. Therefore, it is preferable that the hydrogen concentration / carbon concentration is low to a certain extent. Specifically, it is preferable that the hydrogen concentration / carbon concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side is 1.5 or less. In addition, it is preferable that the hydrogen concentration / carbon concentration in the film of the first metal compound layer 210 is 10 or less. This makes it possible to effectively suppress the dark current.

[0046] 3 shows a graph showing the relationship between the ratio of hydrogen concentration to carbon concentration (hydrogen concentration / carbon concentration) in the first metal compound layer 210 and dark current when the semiconductor layer 100 is made of silicon and the first metal compound layer 210 is made of aluminum oxide. FIG. 3(a) shows the relationship between the hydrogen concentration / carbon concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side and the maximum value of dark current, and FIG. 3(b) shows the relationship between the hydrogen concentration / carbon concentration at the interface of the first metal compound layer 210 on the semiconductor layer 100 side and the minimum value of dark current. As shown in FIG. 3(a), when the hydrogen concentration / carbon concentration at the interface exceeds 1.5, the maximum value of dark current increases significantly, and the dark current can be suppressed by setting the hydrogen concentration / carbon concentration to 1.5 or less. Fig. 3(c) shows the relationship between the hydrogen concentration / carbon concentration in the film of first metal compound layer 210 and the maximum value of dark current, and Fig. 3(d) shows the relationship between the hydrogen concentration / carbon concentration in the film of first metal compound layer 210 and the maximum value of dark current. As shown in Fig. 3(c), when the hydrogen concentration / carbon concentration in the film exceeds 20, the maximum value of dark current increases significantly, and the dark current can be suppressed by setting the hydrogen concentration / carbon concentration to 10 or less. Note that, although the case where semiconductor layer 100 is made of silicon and first metal compound layer 210 is made of aluminum oxide has been considered here, the same applies when semiconductor layer 100 and first metal compound layer 210 are made of other materials.

[0047] [Other embodiments] FIG. 4 is a schematic diagram of a device 9191 including a photoelectric conversion device 930. In addition to the photoelectric conversion device 930, the device 9191 further includes at least one of an optical system 940, a control device 950, a processing device 960, a storage device 970, a display device 980, and a mechanical device 990. The optical system 940 is associated with the photoelectric conversion device 930 and forms an image on the photoelectric conversion device. The control device 950 controls the photoelectric conversion device 930. The processing device 960 processes a signal output from the photoelectric conversion device 930. The storage device 970 stores information obtained by the photoelectric conversion device 930. The display device 980 displays the information obtained by the photoelectric conversion device 930. The mechanical device 990 operates based on the information obtained by the photoelectric conversion device 930. The mechanical device 990 may be a moving device that moves the photoelectric conversion device 930 within the device 9191 or together with the device 9191. By moving the photoelectric conversion device 930 inside the device 9191, an anti-vibration (image stabilizer) function can be realized.

[0048] The photoelectric conversion device 930 may include an electronic device 910 and a mounting member 920, but the mounting member 920 may not be present. The electronic device 910 is a semiconductor device having a semiconductor layer. The electronic device 910 includes a photoelectric conversion area 901 in which photoelectric conversion units are arranged, and a peripheral circuit area 902 in which peripheral circuits (not shown) are arranged. The peripheral circuits include the above-mentioned drive circuits, AD conversion circuits, digital signal processing circuits, control circuits, and the like. The photoelectric conversion area 901 and the peripheral circuit area 902 may be arranged in the same semiconductor layer, but in this example, they may be arranged in separate semiconductor layers (semiconductor substrates) stacked on top of each other.

[0049] The mounting member 920 includes a ceramic package, a plastic package, a printed wiring board, a flexible cable, solder, wire bonding, etc. The optical system 940 is, for example, a lens, a shutter, a filter, or a mirror. The control device 950 is, for example, a semiconductor device such as an ASIC. The processing device 960 is, for example, a semiconductor device such as a CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit) that constitutes an AFE (Analog Front End) or a DFE (Digital Front End). The display device 980 is, for example, an EL display device or a liquid crystal display device. The storage device 970 is, for example, a volatile memory such as an SRAM or a DRAM, or a non-volatile memory such as a flash memory or a hard disk drive, and is, for example, a magnetic device or a semiconductor device. The mechanical device MCHN has a moving part or a propulsion part such as a motor or an engine.

[0050] The device 9191 shown in FIG. 4 may be an electronic device such as an information terminal having a photographing function (for example, a smartphone or a wearable device) or a camera (for example, an interchangeable lens camera, a compact camera, a video camera, or a surveillance camera). The mechanical device 990 in the camera can drive parts of the optical system 940 for zooming, focusing, and shutter operation. The device 9191 may be a transport device (moving object) such as a vehicle, a ship, an aircraft, or an artificial satellite. The mechanical device 990 in the transport device may be used as a moving device. The device 9191 as a transport device is suitable for transporting the photoelectric conversion device 930 or for assisting and / or automating driving (piloting) by using a photographing function. The processing device 960 for assisting and / or automating driving (piloting) can perform processing for operating the mechanical device 990 as a moving device based on information obtained by the photoelectric conversion device 930. The device 9191 may be an analytical device or a medical device.

[0051] The photoelectric conversion device 930 according to this embodiment can provide high value to its designer, manufacturer, seller, purchaser and / or user. Therefore, by mounting the photoelectric conversion device 930 in equipment 9191, the value of the equipment 9191 can also be increased. Therefore, when manufacturing and selling the equipment 9191, it is advantageous to decide to mount the photoelectric conversion device 930 according to this embodiment in the equipment 9191 in order to increase the value of the equipment 9191.

[0052] [Method of manufacturing a photoelectric conversion device] A method for manufacturing a photoelectric conversion device will be described with reference to FIGS.

[0053] 5(a), a semiconductor substrate 1000 on which a photoelectric conversion portion, a transistor including a gate electrode 400, and a wiring structure (not shown) are formed is inverted and bonded to a support substrate (not shown). The support substrate may be a semiconductor substrate 600. The semiconductor substrate 1000 is provided with an element isolation portion 201 having an STI structure on the surface 1002 side. Also, the semiconductor substrate 1000 is provided with an insulating region 216 on the surface 1002 side, in which an insulator is filled in a groove deeper than the element isolation portion 201.

[0054] 5(b), the semiconductor substrate 1000 is thinned from the side opposite the front surface 1002 until the insulating region 216 penetrates the semiconductor substrate 1000 to a thickness of about several tens to several μm, thereby forming the semiconductor layer 100 having the front surface 1002 and the back surface 1001. Methods for thinning include back grinding, chemical mechanical polishing, etching, and the like.

[0055] Next, as shown in FIG. 5(c), a first metal compound layer 210, a second metal compound layer 220, and a silicon compound film 300 are formed on the back surface 1001 of the semiconductor layer 100. The first metal compound layer 210 may be formed by a film formation method using an organic metal gas as a raw material, such as an ALD method or an MOCVD method. In this embodiment, the metal compound 210 is an aluminum oxide layer. The hydrogen concentration and carbon concentration in the aluminum oxide film and at the interface with the semiconductor layer 100 can be adjusted by the film formation conditions of the aluminum oxide layer. Although not shown in FIG. 5 and FIG. 6, an insulating layer 150 having a thickness of about 1 nm is formed between the back surface 1001 of the semiconductor layer 100 and the first metal compound layer 210. In this embodiment, the insulating layer 150 is a silicon oxide layer, and is formed by oxidizing the back surface 1001 of the silicon semiconductor layer 100 when the first metal compound layer 210 is formed by the ALD method.

[0056] The second metal compound layer 220 may be formed, for example, by ALD, MOCVD, PVD, or CVD. The second metal compound layer 220 may be, for example, a tantalum oxide layer, a titanium oxide layer, or the like.

[0057] The silicon compound film 300 may be made of any material generally used in semiconductor devices, such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a carbon-containing silicon oxide film, a fluorine-containing silicon oxide film, etc. The layer structure of the silicon compound film 300 may be a single-layer structure made of one type of material, or a laminate structure made of multiple materials.

[0058] Next, a groove for embedding a metal structure is formed in the silicon compound film 300. Next, as shown in Fig. 5(d), a conductor film 700 is formed over the entire surface of the silicon compound film 300. At this time, the groove in the silicon compound film 300 is embedded with the conductor film 700. The conductor film 700 is, for example, a tungsten film, an aluminum film, or a copper film.

[0059] Next, as shown in FIG. 5(e), the conductive film 700 is patterned. The patterning is performed by photolithography and etching. Through the patterning, a part of the conductive film 700 becomes light shielding members 710 and 711, and a part becomes a guard ring 714. The light shielding member 711 becomes a light shield for optical black pixels and peripheral circuits. At the same time as the light shielding member 710 and the guard ring 714 are formed, a via 713 and a guard ring 712 that connect the light shielding member 710 and the guard ring 714 to the semiconductor layer 100 are formed in the groove of the silicon compound film 300. The guard rings 712 and 714 are arranged so as to surround the outside of the insulating region 216 in a plan view with respect to the surface 1001.

[0060] Next, as shown in Fig. 5(e), an insulating film 810 is formed. The insulating film 810 can be arbitrarily selected from materials generally used in semiconductor devices. For example, it can be a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a carbon-containing silicon oxide film, a fluorine-containing silicon oxide film, etc. The layer structure of the film can be a single layer structure made of one type of material, or a laminate structure made of multiple materials.

[0061] Next, a groove is formed on the surface of the insulator film 810 by etching, then a conductor is formed by PVD or CVD to fill the groove with the conductor, and the conductor on the substrate surface is removed by chemical mechanical polishing, etch-back, etc. As a result, a light-shielding wall 721 is formed on the insulator film 810, as shown in Fig. 5(f). The number of layers of the metal film can be selected arbitrarily.

[0062] Next, a dielectric film 820 is formed on the insulator film 810, and the dielectric film 820 is processed by, for example, photolithography and etching to form an intralayer lens 832 in the dielectric film 820, as shown in FIG. 6(g). The dielectric film 820 can be arbitrarily selected from materials generally used in semiconductor devices. For example, it can be a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a carbon-containing silicon oxide film, a fluorine-containing silicon oxide film, etc. The layer structure of the film can be a single layer structure made of one type of material, or a laminate structure made of multiple materials.

[0063] Next, an insulating film 840 is formed, and a groove is formed from the surface of the insulating film 840 by etching. Next, the groove is filled with a conductor over the entire surface of the substrate by a PVD method or a CVD method. The conductor on the substrate surface is removed by chemical mechanical polishing, etchback, or the like, to form a light-shielding wall 722 in the insulating film 840 as shown in FIG. 6(h). The light-shielding wall 721 and the light-shielding wall 722 are in contact with each other, and the light-shielding wall 721 and the light-shielding wall 722 function as the light-shielding wall 720 shown in FIG. 1. The insulating film 840 can be arbitrarily selected from materials generally used in semiconductor devices. For example, silicon oxide film, silicon nitride film, silicon oxynitride film, carbon-containing silicon oxide film, fluorine-containing silicon oxide film, etc. The layer structure of the film may be a single-layer structure made of one type of material, or a laminate structure made of multiple materials. The material of the light-shielding wall 722 may be tungsten, etc.

[0064] Next, as shown in FIG. 6(i), a planarization film 850, color filters 862 and 863, and a microlens 872 are formed. The blue color filter 863 covers the light shielding member 711. The planarization film 850 can be arbitrarily selected from materials generally used in semiconductor devices. For example, it is a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a carbon-containing silicon oxide film, a fluorine-containing silicon oxide film, or a resin film. The layer structure of the film may be a single layer structure made of one type of material, or a laminate structure made of multiple materials.

[0065] Next, as shown in Fig. 6(j), an opening 888 is formed in the semiconductor layer 100 by dry etching. An aluminum pad (not shown) previously provided in the wiring structure 440 or wiring structure 540 shown in Fig. 1 is exposed at the bottom of the opening 888. Thereafter, the wafer including the semiconductor layer 100 is diced into chips, which are then packaged so that a wire-bonding chip is connected to the pad via the opening 888, thereby obtaining a photoelectric conversion device.

[0066] The embodiments included in this disclosure include not only what is described in the text, but also all matters that can be read from the text and all matters that can be read from the attached drawings. The present embodiment allows addition, deletion, or replacement of components within the scope of the invention. [Explanation of symbols]

[0067] 100 Semiconductor layer 101, 102, 103 Photoelectric conversion unit 1001 Back side (first side) 1002 Surface (2nd side) 200 Metal compound film 210 First metal compound layer 300 Silicon Compound Film 440 Wiring structure 930 Photoelectric conversion device

Claims

1. A semiconductor layer having a plurality of photoelectric conversion units and having a first surface and a second surface opposite to the first surface; a wiring structure disposed on the second surface side of the semiconductor layer; a metal compound film disposed on the first surface side of the semiconductor layer, the metal compound film contains hydrogen and carbon; The hydrogen concentration at the interface of the metal compound film on the semiconductor layer side is 1×10 ２１ atoms / cm ３ Above 1 x 10 ２２ atoms / cm ３ is as follows: The carbon concentration at the interface of the metal compound film on the semiconductor layer side is 5×10 ２０ atoms / cm ３ Above 1 x 10 ２２ atoms / cm ３ is less than or equal to A photoelectric conversion device comprising:

2. The metal compound film has at least one layer selected from the group consisting of a hafnium oxide layer, a zirconium oxide layer, an aluminum oxide layer, a titanium oxide layer, and a tantalum oxide layer.

2. The photoelectric conversion device according to claim 1.

3. The metal compound film is a fixed charge film having a negative fixed charge.

3. The photoelectric conversion device according to claim 1 or 2.

4. The ratio of the hydrogen concentration to the carbon concentration (hydrogen concentration / carbon concentration) at the interface on the semiconductor layer side of the metal compound film is 1.5 or less.

4. The photoelectric conversion device according to claim 1, wherein the first and second electrodes are arranged in a first direction.

5. The ratio of the concentration of hydrogen to the concentration of carbon in the metal compound film (hydrogen concentration / carbon concentration) is 10 or less.

5. The photoelectric conversion device according to claim 1, wherein the first and second electrodes are arranged in a first direction.

6. The concentration of hydrogen in the metal compound film is 5×10 ２０ atoms / cm ３ Above 2 x 10 ２１ atoms / cm ３ is less than or equal to 6. The photoelectric conversion device according to claim 1,

7. The concentration of carbon in the metal compound film is 1×10 １９ atoms / cm ３ Above 1 x 10 ２１ atoms / cm ３ is less than or equal to 7. The photoelectric conversion device according to claim 1,

8. The carbon concentration at the interface of the metal compound film on the semiconductor layer side is 2×10 ２１ atoms / cm ３ Above 1 x 10 ２２ atoms / cm ３ is less than or equal to 8. The photoelectric conversion device according to claim 1, wherein the first and second electrodes are arranged in a first direction.

9. The metal compound film is a multi-layer film having a first metal compound layer and a second metal compound layer from the side closer to the semiconductor layer.

9. The photoelectric conversion device according to claim 1,

10. the first metal compound layer is a layer that is closest to the semiconductor layer among a plurality of layers that constitute the metal compound film, The hydrogen concentration at the interface of the first metal compound layer on the semiconductor layer side is 1×10 ２１ atoms / cm ３ Above 1 x 10 ２２ atoms / cm ３ is as follows: The concentration of carbon at the interface of the first metal compound layer on the semiconductor layer side is 2×10 ２１ atoms / cm ３ Above 1 x 10 ２２ atoms / cm ３ is less than or equal to 10. The photoelectric conversion device according to claim 9.

11. A semiconductor layer having a plurality of photoelectric conversion units and having a first surface and a second surface opposite to the first surface; a wiring structure disposed on the second surface side of the semiconductor layer; a metal compound film disposed on the first surface side of the semiconductor layer, the metal compound film is a multilayer film having a first metal compound layer and a second metal compound layer from the side closer to the semiconductor layer, the first metal compound layer is a layer that is closest to the semiconductor layer among a plurality of layers that constitute the metal compound film, the first metal compound layer contains hydrogen and carbon; The hydrogen concentration at the interface of the first metal compound layer on the semiconductor layer side is 1×10 ２１ atoms / cm ３ Above 1 x 10 ２２ atoms / cm ３ is as follows: The carbon concentration at the interface of the first metal compound layer on the semiconductor layer side is 5×10 ２０ atoms / cm ３ Above 1 x 10 ２２ atoms / cm ３ is less than or equal to A photoelectric conversion device comprising:

12. The concentration of carbon at the interface of the first metal compound layer on the semiconductor layer side is 2×10 ２１ atoms / cm ３ Above 1 x 10 ２２ atoms / cm ３ is less than or equal to The photoelectric conversion device according to claim 11 .

13. The first metal compound layer is any one of a hafnium oxide layer, a zirconium oxide layer, an aluminum oxide layer, a titanium oxide layer, and a tantalum oxide layer.

13. The photoelectric conversion device according to claim 9, wherein the first and second electrodes are arranged in a first direction.

14. The first metal compound layer is an aluminum oxide layer. The photoelectric conversion device according to any one of claims 9 to 13.

15. The second metal compound layer is any one of a hafnium oxide layer, a zirconium oxide layer, an aluminum oxide layer, a titanium oxide layer, and a tantalum oxide layer. The photoelectric conversion device according to any one of claims 9 to 14.

16. The second metal compound layer is a hafnium oxide layer or a tantalum oxide layer. The photoelectric conversion device according to any one of claims 9 to 15.

17. An insulating layer is further provided between the semiconductor layer and the metal compound film, The interface of the metal compound film on the semiconductor layer side is the interface between the metal compound film and the insulating layer. The photoelectric conversion device according to any one of claims 1 to 16.

18. The thickness of the insulating layer is 0.1 nm or more and 10 nm or less.

18. The photoelectric conversion device according to claim 17.

19. The insulating layer is a silicon oxide layer.

19. The photoelectric conversion device according to claim 17 or 18.

20. An apparatus comprising the photoelectric conversion device according to any one of claims 1 to 19, an optical system associated with the photoelectric conversion device; A control device for controlling the photoelectric conversion device; a processing device that processes a signal output from the photoelectric conversion device; a display device that displays information obtained by the photoelectric conversion device; a storage device that stores information obtained by the photoelectric conversion device; and a mechanical device that moves the photoelectric conversion device based on information obtained by the photoelectric conversion device; Further comprising at least one of An apparatus characterized by:

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