JP4811397B2 - Light receiving element and display device - Google Patents

Description

  The present invention relates to a light receiving element including a control electrode and a display device including such a light receiving element.

  In recent years, light receiving elements such as photodiodes have been widely used in display devices such as liquid crystal display devices and organic EL display devices in order to detect and control the brightness and contrast of displayed images. This photodiode is mounted together with a display element having a drive circuit such as a TFT (Thin Film Transistor) in a display device as described above.

  As one type of such a photodiode, a planar PIN photodiode is known. This PIN photodiode includes a p-type semiconductor region and an n-type semiconductor region made of polycrystalline silicon formed on a transparent substrate surface, and an i-type semiconductor made of polycrystalline silicon formed on the transparent substrate surface therebetween ( Intermediate semiconductor) region.

  For example, Patent Document 1 proposes a PIN photodiode in which a threshold voltage is controlled using a third electrode (gate electrode).

JP 2004-119719 A

  By controlling the value of the voltage (gate voltage) applied to the gate electrode as described above, it is considered possible to control not the threshold voltage but the photocurrent generated by receiving light.

  However, in this method, if the gate voltage becomes too high, the electric field in the vicinity of the anode electrode electrically connected to the p-type semiconductor region and the cathode electrode electrically connected to the n-type semiconductor region will be described. Therefore, it is considered that a breakdown phenomenon in which current suddenly flows in the light receiving element is likely to occur. If such a breakdown phenomenon is likely to occur, the ratio of defective products increases due to variations in manufacturing, resulting in a decrease in yield.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a light receiving element capable of improving the yield in manufacturing and a display device including such a light receiving element.

  The light receiving element of the present invention includes a first conductivity type semiconductor region formed on an element formation surface, a second conductivity type semiconductor region formed on the element formation surface, a first conductivity type semiconductor region, and a second conductivity type. An intermediate semiconductor region having an impurity concentration lower than that of these two semiconductor regions on an element formation surface between the semiconductor region and a first electrode electrically connected to the first conductivity type semiconductor region; A second electrode electrically connected to the second conductivity type semiconductor region and a control electrode formed through an insulating film in a region facing the intermediate semiconductor region on the element formation surface. At least one of the first electrode or the electrode electrically connected to the first electrode and the second electrode or the electrode electrically connected to the second electrode is an intermediate semiconductor. It has a counter area formed to face the control electrode through at least a part of the area.

  The display device of the present invention includes a plurality of arranged display elements and the light receiving element.

  In the light receiving element and the display device of the present invention, by applying a voltage to the control electrode, it is possible to control the photocurrent generated when light is irradiated to the intermediate semiconductor region as the light receiving portion. An intermediate semiconductor is connected to at least one of the first electrode or the electrode electrically connected to the first electrode, and the second electrode or the electrode electrically connected to the second electrode. By providing the opposing region that opposes the control electrode through at least a part of the region, the intermediate semiconductor region and the first conductivity type semiconductor region or the semiconductor region compared with the case where such an opposing region is not provided The electric field generated between the second conductivity type semiconductor region is relaxed, and the breakdown phenomenon is less likely to occur.

  According to the light receiving element or the display device of the present invention, at least one of the first electrode or the electrode electrically connected to the first electrode, and the second electrode or the electrode electrically connected to the second electrode. Since one electrode is provided with a facing region that faces the control electrode through at least a part of the intermediate semiconductor region, a breakdown phenomenon occurs compared to the case where such a facing region is not provided. Therefore, it is possible to improve the production yield.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 illustrates a planar configuration of a light receiving element (light receiving element 1) according to an embodiment of the present invention, and FIG. 2 illustrates a cross-sectional configuration along the line II-II of the light receiving element 1 in FIG. It represents.

  The light receiving element 1 is an optical sensor having a so-called PIN photodiode, and includes a glass substrate 10, a p + layer 11 as a first conductivity type semiconductor region provided on one surface thereof, the p + region 11 and the substrate 10. Are provided with an n + layer 12 as a second conductivity type semiconductor region provided on the same surface side, and a light receiving portion 13 as an intermediate semiconductor region provided between the p + region 11 and the n + region 12. The p + layer 11 is electrically connected to the anode electrode 21 via the contact portion 241, and the n + layer 12 is electrically connected to the cathode electrode 22 via the contact portion 242. Further, on the same surface side of the glass substrate 10 as the p + layer 11, the n + layer 12 and the light receiving part 13, a gate electrode 23 having an L length L1 and a W length W1 is formed in a region facing the light receiving part 13. . A gate insulating film 14 is formed between the glass substrate 10 and the gate electrode 23, the p + layer 11, the n + layer 12, and the light receiving unit 13, and the p + layer 11, the n + layer 12, and the light receiving unit 13 An interlayer insulating film 15 is formed between the anode electrode 21 and the cathode electrode 22. The anode electrode 21 is electrically connected to the wiring layer 251, and the cathode electrode 22 is electrically connected to the wiring layer 252.

  The glass substrate 10 is a transparent substrate having optical transparency. Instead of the glass substrate 10, for example, a substrate may be configured using a transparent (light transmissive) material such as plastic, quartz, or aluminum oxide.

  The gate insulating film 14 and the interlayer insulating film 15 are made of an insulating material such as silicon oxynitride (SiN) or silicon oxide (SiO), for example. These may be laminated in a single layer, or may be a mixed layer using a plurality of materials.

  The p + layer 11 is formed on the gate insulating film 14 so as to be in contact with the light receiving portion 13 and is composed of a p-type semiconductor into which p-type impurities are implanted at a high concentration. The p-type impurity is, for example, boron. This p-type semiconductor is preferably composed of, for example, a crystalline semiconductor. This is because the mobility of the carrier can be increased. An example of the crystalline semiconductor is polycrystalline silicon (polysilicon). The p + layer 11 made of polycrystalline silicon is formed, for example, by forming amorphous silicon (amorphous silicon) by a CVD (Chemical Vapor Deposition) method, etc., irradiating with laser light such as an excimer laser, and solidifying it. can do. For this reason, when the display device to be described later is mounted with the light receiving element 1, it can be manufactured on the same substrate together with a driving circuit such as a TFT.

  The n + layer 12 is formed on the gate insulating film 14 so as to be in contact with the light receiving portion 13 and is composed of an n-type semiconductor into which an n-type impurity is implanted at a high concentration. The n-type impurity is, for example, phosphorus. This n-type semiconductor is preferably composed of, for example, a crystalline semiconductor. This is because the carrier mobility can be increased as in the case of the p-type semiconductor. An example of the crystalline semiconductor is polycrystalline silicon. The n + layer 12 made of polycrystalline silicon is preferable because it can be formed by the same manufacturing method as that for the p + layer 11, for example.

The light receiving portion 13 is a light receiving region of the light receiving element 1 and is formed on and in contact with the gate insulating film 14 between the p + layer 11 and the n + layer 12. The light receiving portion 13 has an intermediate semiconductor region (such as about 1 × 10 ^{17 to} 5 × 10 ¹⁸ (atm / cm ² )) having a lower impurity (n-type impurity) concentration than the n + layer 12 (for example, about 1 × 10 ^{17 to} 5 × 10 ¹⁸ (atm / cm ² )). n-layer). The light receiving portion 13 may include a non-single crystal semiconductor layer. Examples of the material of the non-single-crystal semiconductor layer include amorphous silicon, microcrystalline silicon, and polycrystalline silicon.

  Note that the thickness of the amorphous semiconductor layer is preferably as large as possible, for example, about 30 to 60 nm. This is because when the film thickness is small, the photocurrent generated in the light receiving portion 13 decreases, whereas when the film thickness is large, the leakage current increases. The crystal grain size of polycrystalline silicon is preferably about 50 nm to 1 μm. In the case of using microcrystalline silicon formed by a CVD method without using the laser irradiation as described above, the crystal grain size is desirably about 10 to 100 nm.

  The anode electrode 21 is electrically connected to the p + layer 11 and is made of a conductive material.

  The cathode electrode 22 is electrically connected to the n + layer 12 and is made of a conductive material like the anode electrode 21. The cathode electrode 22 is provided with an opposing region (overlap region) d12 that faces the gate electrode 23 (overlaps with a part of the gate electrode 23) through at least a part of the light receiving portion 13. .

  The gate electrode 23 is formed in a region facing the light receiving unit 13 through the gate insulating film 14. The gate electrode 23 functions as a control electrode that can control a photocurrent generated when light is applied to the light receiving unit 13 by applying a voltage.

  Next, referring to FIGS. 3 to 9 in addition to FIGS. 1 and 2, the operation and effect of the light receiving element 1 of the present embodiment will be described in detail in comparison with a comparative example.

  First, the basic operation of the light receiving element 1 will be described with reference to FIGS.

  In the light receiving element 1, when light is incident on the light receiving unit 13 (light enters), a photocurrent is generated in the light receiving unit 13 according to the amount of light, and between the p + layer 11 and the n + layer 12. Flows as a light-receiving element. Further, during such light irradiation, a negative voltage (reverse bias voltage) Vp is applied between the p + layer 11 and the n + layer 12, and the conductivity of the n + layer 12 with respect to the gate electrode 23. When a voltage having the same polarity as the type (n-type) (negative-polarity gate voltage Vg) is applied, the absolute value of the photocurrent I generated in the light receiving unit 13 is, for example, as shown in FIG. Increasing the light receiving sensitivity. Further, the light receiving sensitivity at this time has an optimum range in the magnitude of the gate voltage Vg as shown in FIG. 3B, for example.

  Next, with reference to FIGS. 4 to 9, characteristic actions and effects of the light receiving element 1 will be described in comparison with a comparative example. Here, FIG. 4 shows a planar configuration of the light receiving element (light receiving element 100) according to the comparative example, and FIG. 5 shows a cross-sectional configuration along the line III-III of the light receiving element 1 in FIG. It is a thing.

  In the light receiving element 100 according to this comparative example, unlike the light receiving element 1 of the present embodiment, the cathode electrode 102 is provided with a facing region facing the gate electrode 23 through at least a partial region of the light receiving unit 13. Not. That is, no electrode capable of applying a voltage is provided above the light receiving unit 13 (on the back channel side).

  Therefore, when a negative voltage is applied to the gate electrode 23, for example, as shown in FIG. 6, the back channel side is lifted indefinitely to the negative electrode side. Like the region indicated by reference numeral 13P, the region to be converted to p becomes larger. As a result, the electric field generated between the p-type region 13P in the light receiving portion 13 and the n + layer 12 becomes large, and the tunnel current easily flows, so that a breakdown phenomenon is likely to occur.

  On the other hand, in the light receiving element 1 of the present embodiment, the cathode electrode 22 is provided with a facing region d12 that faces the gate electrode 23 through at least a partial region of the light receiving unit 13. Therefore, when a negative voltage is applied to the gate electrode 23, for example, as shown in FIG. 7, the back channel side is not lifted indefinitely to the negative electrode side by the applied voltage in the facing region d12 in the cathode electrode 22. As in the region indicated by reference numeral 13P in the figure, the p-type region is suppressed in the light receiving unit 13 that is the n− layer. As a result, the electric field generated between the p-type region 13P in the light receiving unit 13 and the n + layer 12 is alleviated. For example, as indicated by reference numeral G11 shown in FIG. The down phenomenon is less likely to occur.

  As described above, in the present embodiment, at least one of the anode electrode 21 or the electrode electrically connected to the anode electrode 21 and the cathode electrode 22 or the electrode electrically connected to the cathode electrode 22 is used. Since the electrode is provided with a facing region facing the gate electrode 23 through at least a partial region of the light receiving portion 13, a breakdown phenomenon occurs compared to a case where such a facing region is not provided. It is possible to make it difficult to improve the yield in manufacturing.

  Specifically, since the facing region d12 is provided in the cathode electrode 22, the above-described effects can be obtained.

The light receiving portion 13 is formed so as to have an impurity (n-type impurity) concentration lower than that of the n + layer 12 (as an n− layer), and has a negative potential with respect to the gate electrode 23 during light irradiation. Since the gate voltage Vg is applied, for example, as shown in FIG. 9, when the L length L1 of the gate electrode 23 is increased, in the conventional case (reference numeral G102), the photocurrent is about L1 = 10 μm. Is saturated, the photocurrent can be increased linearly in a wide range (L1 = about 200 to 400 μm) with respect to the increase in L length (reference numeral G12), and the light receiving sensitivity is improved. Is also possible. This is because electrons are generated in the depletion layer when the light receiving unit 13 serving as an intermediate semiconductor region has a pin type structure along the thickness direction of the light receiving element 1 when irradiated with light. -The hole pair is immediately separated, the probability that the electron-hole pair is trapped in the recombination center is reduced, and the increase in the L length of the light receiving unit 13 contributes to the photocurrent (the photocurrent is reduced). This is because it tends to occur). Further, for example, as shown in FIG. 10, even when the L length L1 is increased, the parasitic capacitance generation regions 11C and 12C, which are overlap regions between the gate electrode 23 and the p + layer 11 or the n + layer 12, increase. Therefore, the degree of freedom of the shape of the light receiving element 1 is also improved. In this case, for example, as shown in FIG. 11, the impurity concentration in the light receiving unit 13 is desirably about 2 × 10 ¹⁸ (atm / cm ² ) or less. This is because when the impurity concentration is higher than this, the breakdown voltage (breakdown voltage) when the gate voltage Vg is applied is drastically reduced.

  Hereinafter, some modified examples of the present invention will be described. In addition, the same code | symbol is attached | subjected to the same thing as the component in the said embodiment, and description is abbreviate | omitted suitably.

[Modification 1]
FIG. 12 illustrates a cross-sectional configuration of a light receiving element (light receiving element 1A) according to Modification 1. In this light receiving element 1A, instead of the cathode electrode 22 in the above-described embodiment, a cathode electrode 22A that does not have the facing region d12 is provided, and the anode electrode 21A passes through at least a part of the region of the light receiving unit 13. A counter region d11 that faces the gate electrode 23 is provided. In addition, the light receiving portion 13 is formed so as to have an impurity (p-type impurity) concentration lower than that of the p + layer 11 (as a p− layer), and has a positive potential with respect to the gate electrode 23 during light irradiation. A gate voltage Vg is applied.

  With such a configuration, also in the light receiving element 1A of the present modification, when a positive voltage is applied to the gate electrode 23, the applied voltage in the facing region d11 in the anode electrode 21A is similar to the above embodiment, The back channel side is not lifted endlessly to the positive electrode side, and the n-type region is suppressed in the light receiving unit 13 that is the p-layer. Thereby, the electric field generated between the light receiving unit 13 and the p + layer 11 is relaxed, and the breakdown phenomenon is less likely to occur. Therefore, also in this modification, it becomes possible to improve the yield at the time of manufacture.

  In addition, the light receiving portion 13 is formed so as to have an impurity (p-type impurity) concentration lower than that of the p + layer 11 (as a p− layer). Since the gate voltage Vg is applied, as in the above embodiment, when the L length L1 of the gate electrode 23 is increased, the photocurrent can be increased linearly over a wide range with respect to the increase in the L length. As a result, the light receiving sensitivity can be improved.

[Modification 2]
FIG. 13 illustrates a cross-sectional configuration of a light receiving element (light receiving element 1B) according to Modification 2. In this light receiving element 1B, the anode electrode 21A is provided with a facing region d11 that faces the gate electrode 23 through at least a partial region of the light receiving unit 13, and at the cathode electrode 22, at least one of the light receiving unit 13 is provided. An opposing region d12 that faces the gate electrode 23 through the region of the part is provided. In addition, the light receiving unit 13 is an intrinsic layer (I layer).

  With such a configuration, in the light receiving element 1B of the present modification, it is possible to make the breakdown phenomenon less likely to occur and improve the manufacturing yield by the same operation as in the above embodiment and Modification 1. Become.

[Modifications 3 to 5]
14 to 16 illustrate cross-sectional configurations of light receiving elements (light receiving elements 1C to 1E) according to Modifications 3 to 5. FIG. In the above embodiment and the first and second modifications, the bottom gate type light receiving element in which the gate electrode 23 is formed below the p + layer 11, the n + layer 12, and the light receiving unit 13 has been described. The elements 1 </ b> C to 1 </ b> E are top gate type light receiving elements in which the gate electrode 23 </ b> C is formed above the p + layer 11, the n + layer 12 and the light receiving unit 13. In these light receiving elements 1C to 1E, interlayer insulating films 160 to 162 and a gate insulating film 14C are formed.

  In the light receiving element 1 </ b> C, an electrode 262 electrically connected to the cathode electrode 22 </ b> C via the contact portion 244 is provided with a facing region d <b> 22 facing the gate electrode 23 through at least a partial region of the light receiving portion 13. Yes. Further, in the light receiving element 1D, an opposing region d21 that faces the gate electrode 23 through at least a part of the region of the light receiving unit 13 is provided in the electrode 261 that is electrically connected to the anode electrode 21D through the contact unit 243. It has been. In the light receiving element 1E, an opposing region d22 that faces the gate electrode 23 through at least a partial region of the light receiving unit 13 is provided in the electrode 262 that is electrically connected to the cathode electrode 22C through the contact unit 244. In addition, the electrode 261 electrically connected to the anode electrode 21D via the contact portion 243 is provided with a facing region d21 that faces the gate electrode 23 via at least a partial region of the light receiving portion 13. Yes.

  With such a configuration, in the light receiving elements 1C to 1E according to the modified examples 3 to 5 as well, it is difficult for the breakdown phenomenon to occur due to the same action as in the above embodiment and the modified examples 1 and 2, and at the time of manufacturing. Yield can be improved.

  Although the present invention has been described with reference to the embodiment and the modification examples, the present invention is not limited to the embodiment and the like, and various modifications can be made.

  For example, in at least one of the cathode electrode or the electrode electrically connected to the cathode electrode and the anode electrode or the electrode electrically connected to the anode electrode described in the above embodiment, It is preferable that at least the portions of the facing regions (facing regions d11, d12, d21, d22) are transparent electrodes made of a transparent material such as ITO (Indium Tin Oxide). In such a configuration, the light incident efficiency with respect to the light receiving unit is improved, so that the light receiving sensitivity can be further improved.

  In addition, the present invention is not limited to the effect in visible light, and can also be effective in invisible light (for example, X-rays, electron beams, ultraviolet light, and infrared light). In particular, if the present invention is used for light in the vicinity of the band gap of the semiconductor layer, an effective light receiving element can be configured.

  In the present invention, a silicon thin film is mainly used as a semiconductor layer, but any semiconductor material that can be controlled by an electric field may be used. For example, SiGe, Ge, Se, an organic semiconductor film, an oxide semiconductor A film or the like can be used.

  In addition, the light receiving element of the present invention can be applied to a display device including a display element and a light receiving element, such as the liquid crystal display device 4 and the organic EL display device 5 shown in FIGS. This makes it possible to receive external ambient light and display light from the display unit 48, etc., and control display data, backlight light quantity, etc., and have a touch panel function, fingerprint input function, scanner function, etc. It becomes possible to function as a multi-function display. Specifically, the liquid crystal display device 4 shown in FIG. 17 includes the light receiving element 1 and the like described in the above embodiments, the source electrode 3N21, the drain electrode 3N22, the gate electrodes 3N231 and 3N232, and the channel layers 3N131 and 3N132. N-type TFT 3N having n + layer 3N12 and LDD (Lightly Doped Drain) layer 3N14, P-type TFT 3P having source electrode 3P22, drain electrode 3P21, gate electrode 3P23, channel layer 3P13 and p + layer 3P11, and planarizing film 41 A pixel electrode 421, a common electrode 422, a liquid crystal layer 43, a spacer 44, an overcoat layer 45, a black matrix layer 46, a color filter layer 47, and a glass substrate 40. Each pixel 49 in the display unit 48 includes, for example, a data line DL, gate lines GL1 to GL3, a power supply line VDD, a ground line GND, a common line COM, a lead line RL, and a liquid crystal element as shown in FIG. A pixel circuit having an LC, a light receiving element 1, pixel selecting TFT elements SW1 and SW3, a capacitive element C1, and a source follower element SF is formed. Further, the organic EL display device 5 shown in FIG. 19 includes the light receiving element 1 described in the above embodiment, the N-type TFT 3N, the P-type TFT 3P, the planarizing film 51, the anode electrode 521, A cathode electrode 522, a light emitting layer 53, a resin layer 54, an overcoat layer 55, a black matrix layer 56, a color filter layer 57, and a glass substrate 50 are provided. The light receiving element 1 and the like are not limited to being provided in each pixel 49, and may be provided at the outer edge of the display unit 48, for example, as in the liquid crystal display device 4A shown in FIG.

  Moreover, you may make it combine the structure etc. which were demonstrated in the said embodiment etc.

It is a top view showing the structure of the light receiving element which concerns on one embodiment of this invention. It is sectional drawing showing the structure of the light receiving element shown in FIG. It is a characteristic view for demonstrating the basic effect | action of the light receiving element shown in FIG. It is a top view showing the structure of the light receiving element which concerns on a comparative example. It is sectional drawing showing the structure of the light receiving element which concerns on the comparative example shown in FIG. It is sectional drawing for demonstrating the effect | action of the light receiving element which concerns on the comparative example shown in FIG. It is sectional drawing for demonstrating the characteristic effect | action of the light receiving element shown in FIG. FIG. 5 is a characteristic diagram illustrating a relationship between a gate voltage and a photocurrent in the light receiving element illustrated in FIGS. 1 and 4. FIG. 5 is a characteristic diagram illustrating a relationship between an L length of a gate electrode and a photocurrent in the light receiving element illustrated in FIGS. 1 and 4. It is a top view for demonstrating the relationship between the parasitic capacitance generation area | region and photocurrent in a light receiving element. FIG. 2 is a characteristic diagram illustrating a relationship between an impurity concentration of a light receiving portion and a breakdown voltage in the light receiving element illustrated in FIG. 1. It is sectional drawing showing the structure of the light receiving element which concerns on the modification 1 of this invention. It is sectional drawing showing the structure of the light receiving element which concerns on the modification 2 of this invention. It is sectional drawing showing the structure of the light receiving element which concerns on the modification 3 of this invention. It is sectional drawing showing the structure of the light receiving element which concerns on the modification 4 of this invention. It is sectional drawing showing the structure of the light receiving element which concerns on the modification 5 of this invention. It is sectional drawing showing an example of the liquid crystal display device provided with the light receiving element shown in FIG. FIG. 18 is a plan view and a circuit diagram illustrating an example of a pixel circuit in the liquid crystal display device illustrated in FIG. 17. It is sectional drawing showing an example of the organic electroluminescent display apparatus provided with the light receiving element shown in FIG. It is a top view showing the other example of the liquid crystal display device provided with the light receiving element shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,1A-1E ... Light receiving element, 10 ... Glass substrate, 11 ... p + layer, 12 ... n + layer, 11C, 12C ... Parasitic capacitance generating region, 13 ... Light receiving part, 13P ... P-type region, 14, 14C ... Gate insulation Film, 15, 160 to 162 ... Interlayer insulating film, 21, 21A, 21D ... Anode electrode, 22, 22A, 22C ... Cathode electrode, 23, 23C ... Gate electrode, 241-244 ... Contact part, 251, 252 ... Wiring layer 261, 262 ... electrodes, 3N ... N-type TFT, 3P ... P-type TFT, 4,4A ... liquid crystal display device, 40 ... glass substrate, 41 ... flattening film, 421 ... pixel electrode, 422 ... common electrode, 43 ... Liquid crystal layer, 44 ... spacer, 45 ... overcoat layer, 46 ... black matrix layer, 47 ... color filter layer, 48 ... display unit, 49 ... pixel, 5 ... organic EL display device, 50 ... gas Substrate 51, planarizing film, 521, anode electrode, 522, cathode electrode, 53 ... light emitting layer, 54 ... resin layer, 55 ... overcoat layer, 56 ... black matrix layer, 57 ... color filter layer, L1 ... gate L length of electrode, W1... W length of gate electrode, d11, d12, d21, d22... Overlap region (opposite region).

Claims (13)

A first conductivity type semiconductor region formed on the element formation surface;
A second conductivity type semiconductor region formed on the element formation surface;
An intermediate semiconductor region formed on the element formation surface between the first conductive type semiconductor region and the second conductive type semiconductor region and having an impurity concentration lower than those two semiconductor regions;
A first electrode electrically connected to the first conductivity type semiconductor region;
A second electrode electrically connected to the second conductivity type semiconductor region;
A control electrode formed through an insulating film in a region facing the intermediate semiconductor region on the element formation surface;
At least one of the first electrode or the electrode electrically connected to the first electrode and the second electrode or the electrode electrically connected to the second electrode is the intermediate semiconductor region. A light receiving element, comprising: a counter region formed so as to be opposed to the control electrode through at least a part of the region. The first electrode is an anode electrode and the second electrode is a cathode electrode;
The light receiving element according to claim 1, wherein the cathode electrode or an electrode electrically connected to the cathode electrode has the facing region. The light receiving element according to claim 2, wherein a second conductivity type impurity is implanted into the intermediate semiconductor region so that an impurity concentration is lower than that of the second conductivity type semiconductor region. The light receiving element according to claim 3, wherein a negative voltage is applied to the control electrode. The first electrode is an anode electrode and the second electrode is a cathode electrode;
The light receiving element according to claim 1, wherein the anode electrode or an electrode electrically connected to the anode electrode has the facing region. The light receiving element according to claim 5, wherein an impurity of a first conductivity type is implanted in the intermediate semiconductor region so that an impurity concentration is lower than that of the first conductivity type semiconductor region. The light receiving element according to claim 6, wherein a positive voltage is applied to the control electrode. The first electrode or the electrode electrically connected to the first electrode, and the second electrode or the electrode electrically connected to the second electrode each have the facing region. The light receiving element according to claim 1. The light receiving element according to claim 8, wherein the intermediate semiconductor region is an intrinsic layer (I layer). The light receiving element according to claim 1, wherein the control electrode is formed in a layer lower than the first conductive type semiconductor region, the second conductive type semiconductor region, and the intermediate semiconductor region. The light receiving element according to claim 1, wherein the control electrode is formed in an upper layer than the first conductive semiconductor region, the second conductive semiconductor region, and the intermediate semiconductor region. The light receiving element according to claim 1, wherein at least a portion of the facing region in the at least one electrode is a transparent electrode. A display device comprising a plurality of arranged display elements and light receiving elements,
The light receiving element is
A first conductivity type semiconductor region formed on the element formation surface;
A second conductivity type semiconductor region formed on the element formation surface;
An intermediate semiconductor region formed on the element formation surface between the first conductive type semiconductor region and the second conductive type semiconductor region and having an impurity concentration lower than those two semiconductor regions;
A first electrode electrically connected to the first conductivity type semiconductor region;
A second electrode electrically connected to the second conductivity type semiconductor region;
A control electrode formed through an insulating film in a region facing the intermediate semiconductor region on the element formation surface;
At least one of the first electrode or the electrode electrically connected to the first electrode and the second electrode or the electrode electrically connected to the second electrode is the intermediate semiconductor region. A display device comprising: an opposing region formed to face the control electrode through at least a part of the region.

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