JP5578138B2 - Optical sensor and manufacturing method thereof - Google Patents

Description

  In the present invention, a plurality of light receiving elements are formed on a semiconductor substrate, a light shielding film is formed on the surface of the semiconductor substrate where the light receiving elements are formed via a light transmitting film, and a light transmitting opening is formed in the light shielding film. The present invention relates to an optical sensor and a method for manufacturing the same.

  Conventionally, as shown in, for example, Patent Document 1, a plurality of photodiodes are formed on a semiconductor substrate, a light-transmitting light-transmitting layer is formed on the formation surface, and the light-transmitting layer has a light-blocking property. There has been proposed an optical sensor in which a plurality of light propagation areas are formed on the light shielding mask. In this optical sensor, the range of light incident on the light receiving surface of the photodiode is defined by the light propagation area of the light shielding mask.

US Pat. No. 6,875,974

  In the optical sensor shown in Patent Document 1, two photodiodes forming a pair are adjacent in the left-right direction, and the range of light incident on the light receiving surface of each of the two photodiodes is above the two photodiodes. It is defined by one located light propagation area. Therefore, when light enters the optical sensor from the left, the output signal of the right photodiode is larger than the output signal of the left photodiode. On the contrary, when light enters the optical sensor from the right side, the output signal of the left photodiode is larger than the output signal of the right photodiode. Therefore, it is possible to detect whether light is incident from the left side or from the right side by comparing the output signals of the two photodiodes forming a pair.

  By the way, in the above configuration, the value (first value) obtained by dividing the output signal of the left photodiode by the sum of the output signals of the two photodiodes forming the pair, and the output signal of the right photodiode, By calculating the value (second value) divided by the sum of the output signals of the two photodiodes that make a pair, and taking the ratio of these two values, the light from the left side of the photosensor It is possible to detect how much is incident or how much is incident from the right side. That is, the right / left ratio of light can be detected.

  However, as described above, in Patent Document 1, a light-shielding mask is formed on a photodiode formation surface (light-receiving surface) via a light-transmitting layer, and a light propagation area is formed in the light-shielding mask. If manufacturing variations occur in this light propagation area, there is a risk that the detection accuracy of the above-described left-right ratio will be reduced.

  In view of the above problems, an object of the present invention is to provide an optical sensor in which a decrease in detection accuracy of the right / left ratio of light is suppressed, and a manufacturing method thereof.

In order to achieve the above object, according to the first aspect of the present invention, a plurality of light receiving elements (20) are formed on a semiconductor substrate (10), and a formation surface (10a) of the light receiving elements (20) on the semiconductor substrate (10). ), A light-shielding film (40) is formed on the light-shielding film (30), and a light-transmitting opening (50) is formed on the light-shielding film (40). A pair of light receiving elements (21, 21) having a line-symmetrical relationship via a virtual straight line (VL) along one direction of the formation surface (10a). 22) is formed in the semiconductor substrate (10), and a pair of openings (51, 52) having a line-symmetrical relationship via a virtual straight line (VL) correspond to the pair of light receiving elements (21, 22). Formed on the light-shielding film (40) and along the height direction perpendicular to the formation surface (10a) Part of the projection surface of each of the pair of openings (51, 52) projected onto 10a) is overlapped with the light receiving surface of the corresponding light receiving element, and light along the height direction is passed through the openings (51, 52). When the light receiving element (21, 22) is irradiated through the light, the light along the height direction is directed to the opening (51, 52) based on the output signals output from the pair of light receiving elements (21, 22). A correction unit (60) for correcting each output signal so that the output signals of the pair of light receiving elements (21, 22) output when the light enters the light receiving element (21, 22) via The output signal of one light receiving element (21) of the pair of light receiving elements (21, 22) is S1, the other output signal is S2, and the light along the height direction passes through the openings (51, 52). The output signal S1 when incident on the light receiving element (21, 21) is SV1, Assuming that the signal S2 is SV2, the correction unit (60) stores the first correction number ΔG1 = (SV2−SV1) / (SV1 + SV2), and multiplies the output signal S1 by (1−ΔG1). ) Is multiplied by the output signal S2 to correct the output signals S1 and S2 .

  Thus, according to the present invention, each of the pair of light receiving elements (21, 22) and the pair of openings (51, 52) is line symmetric via the virtual straight line (VL). A part of the projection surface of the opening (51, 52) overlaps the light receiving surface of the corresponding light receiving element (21, 22). According to this, when light along the height direction enters the light receiving element (21, 22) through the opening (51, 52), it is output from each of the pair of light receiving elements (21, 22). The output signals (hereinafter referred to as reference signals) are expected to be the same. However, if manufacturing variations occur in the openings (51, 52), the overlapping areas of the light receiving surface and the projection surface are different and the reference signals are different due to the manufacturing variation. As a result, a value (first value) obtained by dividing the output signal of one light receiving element (21) by the sum of the output signals of the two light receiving elements (21, 22) and the output signal of the other light receiving element (22). Is different from the value (second value) divided by the sum of the output signals of the two light receiving elements (21, 22), and the detection accuracy of the right / left ratio of light, which is the ratio of these two values, may be reduced. is there.

  On the other hand, according to the first aspect of the present invention, the output signals of the light receiving elements (21, 22) so that the reference signals are matched based on the reference signals of the pair of light receiving elements (21, 22). Correct. According to this, since the manufacturing variation of the openings (51, 52) included in the output signal of each light receiving element (21, 22) is corrected, a decrease in the detection accuracy of the right / left ratio of light is suppressed. The

Further, in claim 1 , the output signal of one light receiving element (21) of the pair of light receiving elements (21, 22) is S1, the other output signal is S2, and the light along the height direction is the opening (51, 52), when the output signal S1 when incident on the light receiving element (21, 21) is SV1 and the output signal S2 is SV2, the correction unit (60) has the first correction number ΔG1 = (SV2−SV1) / (SV1 + SV2) stores a (1 + .DELTA.G1) multiplies the output signal S1, and by multiplying the output signal S2 of (1-.DELTA.G1), you correct each output signals S1, S2.

  As described in claim 1, the light-transmitting film (30) and the light-shielding film (40) are laminated on the formation surface (10a). In the process of laminating them, the films (30, 40 at the time of design) are stacked. ) There is a possibility that the arrangement position of the film (30, 40) may be shifted so that the shape and the shape of the opening (51, 52) are maintained in parallel. When the arrangement position is shifted, the overlapping area (hereinafter referred to as the first overlapping area) between the light receiving surface of one of the light receiving elements (21) of the pair of light receiving elements (21, 22) and the projection surface of the corresponding opening (51). J1) decreases, and the overlapping area (hereinafter referred to as second overlapping area J2) between the light receiving surface of the other light receiving element (22) and the projection surface of the corresponding opening (52) increases.

  The amount of decrease and the amount of increase are the same, and the amount corresponds to the displacement of the arrangement position (manufacturing variation of the opening) (hereinafter, the amount of displacement is denoted by ΔJ). Therefore, if the overlapping area (design area) when there is no manufacturing variation is J, J1 = J−ΔJ and J2 = J + ΔJ are established.

  The overlapping areas J1 and J2 and the output signals SV1 and SV2 are in a proportional relationship. Therefore, approximately SV1 / SV2 = J1 / J2 is established. Substituting J1 = J−ΔJ and J2 = J + ΔJ into this equation and solving for ΔJ, ΔJ = J × (SV2−SV1) / (SV1 + SV2) = JΔG1. Therefore, when the output signal of the light receiving element (21, 22) when there is no manufacturing variation is SV, the deviation ΔS of the output signal due to the manufacturing variation is expressed as SVΔG1.

  In one light receiving element (21), since the overlapping area is reduced, the output signal is reduced by ΔS. Therefore, if ΔS is added to one output signal S1, the manufacturing variation is corrected. The value is approximately expressed as (1 + ΔG1) S1. On the other hand, in the other light receiving element (22), since the overlapping area is increased, the output signal is increased by ΔS. Therefore, if the difference is ΔS from the other output signal S2, the manufacturing variation is corrected. The value is approximately expressed as (1-ΔG1) S2.

  As described above, the output signals S1 and S2 are corrected by multiplying the output signal S1 by (1 + ΔG1) and multiplying the output signal S2 by (1−ΔG1). Note that the decrease and increase in the overlap area can be determined by comparing the output signals SV1 and SV2.

According to a second aspect of the present invention, along the formation surface (10a), a part of the projection surface protrudes from the light receiving surface in a direction perpendicular to the virtual straight line (VL), and the projection surface and the light receiving surface are formed into the formation surface (10a). A configuration in which the planar shape formed on the upper surface is substantially convex is preferable.

  For ease of explanation, the direction along the virtual straight line (VL) is indicated as the front-rear direction, the direction along the formation surface (10a), and the direction perpendicular to the virtual straight line (VL) is indicated as the left-right direction. According to this, the planar shape formed by the projection surface and the light receiving surface is a substantially convex shape in which a part of the projection surface protrudes in the left-right direction. In the case of this configuration, since the light receiving surface is located in the front-rear direction of the projection surface, the arrangement positions of the light-transmitting film (30) and the light-shielding film (40) may be shifted not only in the left-right direction but also in the front-rear direction. The overlap area is suppressed from increasing or decreasing due to the shift in the front-rear direction. This more effectively suppresses the left / right ratio detection accuracy from being reduced due to manufacturing variations.

According to a third aspect of the present invention, the light shielding film (40) is formed in multiple layers on the light transmissive film (30), and the opening angle (50) formed in the light shielding film (40) of each layer increases the elevation angle of light. The specified configuration is good. According to this, since the multilayer light shielding film (40) is located between the pair of light receiving elements (21, 22), the light incident from the certain opening (51) corresponds to the opening (51). Incident light receiving elements (22) other than the receiving light receiving element (21) are suppressed. Thereby, it is suppressed that disturbance noise is contained in the output signal of each light receiving element (21, 22).

The operational effects of the inventions according to claims 4 to 6 are the same as the operational effects of the invention according to any one of claims 1 to 3, so the description thereof is omitted.

It is a top view which shows schematic structure of the optical sensor which concerns on 1st Embodiment. It is sectional drawing which follows the II-II line | wire of FIG. It is a block diagram for demonstrating schematic structure of a correction | amendment part. It is a top view which shows the modification of an optical sensor. It is a top view which shows the modification of an optical sensor.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment when an optical sensor according to the present invention is mounted on a vehicle will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a plan view showing a schematic configuration of the photosensor according to the first embodiment. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is a block diagram for explaining a schematic configuration of the correction unit. In FIG. 1, light receiving elements 21 and 22 described later are indicated by broken lines, the overlapping areas J1 and J2 are hatched, and the correction unit 60 is omitted. In the following, the direction passing through the front and rear of the vehicle along the formation surface 10a of the light receiving element 20 is indicated as the front-rear direction, and the direction passing through the left and right of the vehicle along the formation surface 10a is indicated as the left and right direction. And the direction orthogonal to the formation surface 10a is shown as a height direction.

  The optical sensor 100 is mounted on the front panel of the vehicle and is mainly used to detect the position of the sun. As shown in FIGS. 1 to 3, the optical sensor 100 includes, as main parts, a semiconductor substrate 10, a light receiving element 20, a light transmissive film 30, a light shielding film 40, an opening 50, a correction unit 60, Have The light receiving element 20 is formed on the formation surface 10 a side of the semiconductor substrate 10, the light transmitting film 30 is formed on the formation surface 10 a of the light receiving element 20, and the light shielding film 40 is formed on the light transmitting film 30. A light-transmitting opening 50 is formed in the light shielding film 40, and light enters the light receiving element 20 through the opening 50. The output signal of the light receiving element 20 is converted into a digital signal by an AD conversion circuit (not shown), then output to the correction unit 60, corrected by the correction unit 60, and then output to an external element (not shown). Is done.

  The semiconductor substrate 10 has a rectangular shape, and the above-described light receiving element 20 and electronic elements (not shown) constituting the correction unit 60 are formed. These electronic elements are electrically connected via a wiring pattern (not shown) formed on the semiconductor substrate 10.

  The light receiving element 20 converts light into an electrical signal. The light receiving element 20 according to the present embodiment is a photodiode having a PN junction, and is formed on the formation surface 10 a side of the semiconductor substrate 10. As shown in FIG. 1, a pair of light receiving elements 21 and 22 are formed on the forming surface 10 a in a line-symmetric relationship via a virtual straight line VL along the front-rear direction.

  The translucent film 30 is made of a material having optical transparency and insulating properties. An example of a material having such properties is an acrylic resin. As shown in FIG. 2, the translucent film 30 is formed as a single layer on the formation surface 10a.

  The light shielding film 40 is made of a material having light shielding properties and conductivity. An example of a material having such properties is aluminum. As shown in FIG. 2, the light shielding film 40 is formed in a single layer on the light transmitting film 30, and an opening 50 for light transmission is formed. Although not shown, the light shielding film 40 is electrically connected to a wiring pattern formed on the semiconductor substrate 10 and functions as a wiring for electrically connecting each electronic element.

  The opening 50 defines light incident on the light receiving element 20. As shown in FIG. 1, the light shielding film 40 is formed with a pair of openings 51 and 52 that are in a line-symmetric relationship via a virtual straight line VL. These openings 51 and 52 define the elevation angle of light incident on the light receiving elements 21 and 22, and the position of the openings 51 and 52 and the light receiving elements 21 and 22 determines the light incident on the light receiving elements 21 and 22. Left and right corners are defined.

  The correction unit 60 corrects the output signals S1, S2 of the light receiving elements 21, 22. The correction unit 60 stores a later-described first correction number ΔG1 and calculates a multiplication unit 61 that multiplies the input signal by the first correction number ΔG1, and outputs signals from the light receiving elements 21 and 22 and an output signal from the multiplication unit 61. And an arithmetic unit 62.

  Next, a method for manufacturing the optical sensor 100 according to the present embodiment will be described. First, the pair of light receiving elements 21 and 22 are formed on the formation surface 10a side so as to be line symmetric via the virtual straight line VL. The above is the element forming process.

  After the element formation step, the light-transmitting film 30 and the light-shielding film 40 are formed on the formation surface 10a so that the pair of openings 51 and 52 are symmetric with respect to the virtual straight line VL. The above is the film forming process.

  After the film forming step, light along the height direction is irradiated to the light receiving elements 21 and 22 through the openings 51 and 52, and the output signals SV1 and SV2 of the pair of light receiving elements 21 and 21 are detected. Then, SV1 and SV2 are compared, and when SV1 is lower than SV2, (SV2−SV1) / (SV1 + SV2) is stored in the multiplier 61 as the first correction number ΔG1. The calculation unit 62 is programmed to calculate (1 + ΔG1) S1 obtained by adding the output signals ΔG1S1 and S1 of the multiplication unit 61 and (1−ΔG1) S2 obtained by subtracting the output signals ΔG1S2 and S2 of the multiplication unit 61. To do. On the contrary, when SV1 is larger than SV2, (SV1−SV2) / (SV1 + SV2) is stored in the multiplier 61 as the first correction number ΔG1. Then, the calculation unit 62 is programmed to calculate (1−ΔG1) S1 and (1 + ΔG1) S2. The above is the storage process.

  The optical sensor 100 is manufactured by performing the above processes. In the present embodiment, it is assumed that SV1 is lower than SV2, and the first correction number ΔG1 = (SV2−SV1) / (SV1 + SV2) is stored in the multiplier 61. Further, it is assumed that the calculation unit 62 is programmed to calculate (1 + ΔG1) S1 and (1−ΔG1) S2.

  Next, feature points of the optical sensor 100 according to the present embodiment will be described. As described above, the pair of light receiving elements 21 and 22 are line symmetric with respect to the virtual line VL, and the pair of openings 51 and 52 are line symmetric with respect to the virtual line VL. The first light receiving element 21 is located on the left side from the virtual straight line VL, and the second light receiving element 22 is located on the right side from the virtual straight line VL. Similarly, the first opening 51 is located to the left from the virtual straight line VL, and the second opening 52 is located to the right from the virtual straight line VL.

  As shown in FIG. 1, a part of the projection surface of the openings 51 and 52 projected onto the formation surface 10 a by light along the height direction overlaps with the light receiving surfaces of the corresponding light receiving elements 21 and 22. Thereby, when the light receiving elements 21 and 22 are irradiated with light along the height direction through the openings 51 and 52, the output signals SV1 and SV2 output from the light receiving elements 21 and 22 may be the same. Be expected.

  Further, as shown in FIG. 1, the remaining part of the projection surface protrudes from the light receiving surface toward the virtual straight line VL along the left-right direction, and the projection surface and the light receiving surface are formed on the formation surface 10a. Has a substantially convex shape. Due to this shape, the first light receiving element 21 easily receives light incident from the right side through the first opening 51 and hardly receives light incident from the left side. On the other hand, the second light receiving element 22 is easy to receive light incident from the left through the second opening 52 and is difficult to receive light incident from the right. Further, the first light receiving element 21 receives light incident from the right front and right rear through the first opening 51 to the same extent as light incident from the right, and in the front-rear direction of the light It becomes difficult to depend on ingredients. Similarly, the second light receiving element 22 receives light incident from the left front and left rear via the second opening 52 to the same extent as light incident from the left, and in the longitudinal direction of the light. It becomes difficult to depend on ingredients.

  The correction unit 60 corrects the output signals S1 and S2 of the light receiving elements 21 and 22 based on the output signals SV1 and SV2 so that the output signals SV1 and SV2 coincide with each other. The multiplication unit 61 outputs ΔG1S1 and ΔG1S2 obtained by multiplying the output signals S1 and S2 by ΔG1, and this output signal is input to the calculation unit 62. The calculating unit 62 calculates (1 + ΔG1) S1 obtained by adding the output signals ΔG1S1 and S1 of the multiplying unit 61 and (1−ΔG1) S2 obtained by subtracting the output signals ΔG1S2 and S2 of the multiplying unit 61, and outputs the calculated signal. Output to external element. This calculation corresponds to “(1 + ΔG1) multiplied by the output signal S1 and (1−ΔG1) multiplied by the output signal S2” described in the claims.

  In the external element, the corrected first light-receiving element based on the output signal of the calculation unit 62, that is, the output signals (1 + ΔG1) S1 and (1-ΔG1) S2 of the light-receiving elements 21 and 22 corrected by the correction unit 60 21 (the first value) obtained by dividing the output signal 21 by the sum of the output signals of the two light receiving elements 21 and 22 after correction, and the two light receptions after correcting the output signal of the second light receiving element 22 after correction. A value (second value) divided by the sum of the output signals of the elements 21 and 22 is calculated. Then, the right / left ratio of light, which is the ratio of these two values, is calculated. The incident angle of light is approximated by this left / right ratio. Further, based on the left / right ratio and the corrected output signals (1 + ΔG1) S1 and (1−ΔG1) S2 of the light receiving elements 21 and 22, the light irradiation amount is estimated.

  Next, functions and effects of the optical sensor 100 according to the present embodiment will be described. As described above, when the light receiving elements 21 and 22 are irradiated with light along the height direction through the openings 51 and 52, the output signals SV1 and SV2 output from the light receiving elements 21 and 22 are the same. It is expected. However, if manufacturing variations occur in the openings 51 and 52, the overlapping areas of the light receiving surface and the projection surface differ and the output signals SV1 and SV2 differ due to the manufacturing variation. As a result, the first value and the second value described above are different, and the detection accuracy of the right / left ratio of light, which is the ratio of these two values, may be reduced.

  On the other hand, in the present embodiment, the output signals S1 and S2 are corrected based on the output signals SV1 and SV2 so that the output signals SV1 and SV2 coincide with each other. According to this, since the manufacturing variation of the openings 51 and 52 included in the output signals of the light receiving elements 21 and 22 is corrected, a decrease in the detection accuracy of the right / left ratio of light is suppressed.

  The multiplication unit 61 stores the first correction number ΔG1 = (SV2−SV1) / (SV1 + SV2), multiplies ΔG1 by the output signals S1 and S2, and outputs the output signal ΔG1S1 of the multiplication unit 61. And (1 + ΔG1) S1, and (1−ΔG1) S2 is calculated by subtracting the output signals ΔG1S2 and S2 of the multiplier 61 from each other.

  The light-transmitting film 30 and the light-shielding film 40 are laminated on the formation surface 10a. In the process of laminating them, the film 30 and 40 at the time of design and the shape of the opening 50 are maintained in parallel translation. As described above, the arrangement positions of the films 30 and 40 may be shifted. When the arrangement position is shifted, an overlapping area (hereinafter, referred to as a first overlapping area J1) between the light receiving surface of the first light receiving element 21 and the projection surface of the first opening 51 corresponding to the first light receiving element 21 is reduced. The overlapping area (hereinafter referred to as second overlapping area J2) between the light receiving surface and the corresponding projection surface of the second opening 52 increases. Alternatively, the first overlapping area J1 increases and the second overlapping area J2 decreases. The overlapping areas J1 and J2 and the output signals SV1 and SV2 are in a proportional relationship. In this embodiment, since SV1 is lower than SV2, the first overlapping area J1 decreases and the second overlapping area J2 increases. Will be doing.

  The amount of decrease and the amount of increase are the same, and the amount corresponds to the displacement of the arrangement position (manufacturing variation of the opening 50) (hereinafter, the amount of displacement is denoted by ΔJ). Therefore, if the overlapping area (design area) when there is no manufacturing variation is J, J1 = J−ΔJ and J2 = J + ΔJ are established.

  As described above, the overlapping areas J1 and J2 and the output signals SV1 and SV2 are in a proportional relationship. Therefore, approximately SV1 / SV2 = J1 / J2 is established. Substituting J1 = J−ΔJ and J2 = J + ΔJ into this equation and solving for ΔJ, ΔJ = J × (SV2−SV1) / (SV1 + SV2) = JΔG1. Therefore, when the output signal of the light receiving elements 21 and 22 when there is no manufacturing variation is SV, the output signal shift amount ΔS due to the manufacturing variation is expressed as SVΔG1.

  In the first light receiving element 21, since the overlapping area is reduced, the output signal is reduced by ΔS. Accordingly, if ΔS is added to the output signal S1, the manufacturing variation is corrected. The value is approximately expressed as (1 + ΔG1) S1. On the contrary, in the second light receiving element 22, since the overlapping area is increased, the output signal is increased by ΔS. Therefore, if the difference is ΔS from the output signal S2, the manufacturing variation is corrected. The value is approximately expressed as (1-ΔG1) S2.

  As described above, each output signal S1, S2 is corrected by calculating (1 + ΔG1) S1 and calculating (1−ΔG1) S2.

  As shown in FIG. 1, the planar shape formed by the projection surface and the light receiving surface has a substantially convex shape in which a part of the projection surface protrudes in the left-right direction. In the case of this configuration, since the light receiving surface is positioned in the front-rear direction of the projection surface, even if the arrangement positions of the light-transmitting film 30 and the light-shielding film 40 are shifted not only in the left-right direction but also in the front-rear direction. The overlap area is prevented from increasing or decreasing due to the deviation. This more effectively suppresses the left / right ratio detection accuracy from being reduced due to manufacturing variations.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the present embodiment, an example in which the optical sensor 100 is mounted on a vehicle is shown. However, the application of the optical sensor 100 is not limited to the above example.

  In the present embodiment, an example in which ΔG1S1 and ΔG1S2 obtained by multiplying the output signals S1 and S2 by ΔG1 is output from the multiplication unit 61 is shown. However, each time the output signals S1 and S2 are input, the multiplication unit 61 calculates the second correction number ΔG2 = (S2−S1) / (S1 + S2) + ΔG1, and outputs ΔG2S1 and ΔG2S2 obtained by multiplying them. Also good. In this case, the calculating unit 62 calculates (1 + ΔG2) S1 obtained by adding the output signals ΔG2S1 and S1 of the multiplying unit 61 and (1−ΔG2) S2 obtained by subtracting the output signals ΔG2S2 and S2 of the multiplying unit 61 to calculate The signal is output to an external element.

  The above (1 + ΔG2) can be expressed as 2S2 / (S1 + S2) + ΔG1, and (1−ΔG2) can be expressed as 2S1 / (S1 + S2) + ΔG1. These second terms are terms for correcting manufacturing variations, and the first term is obtained by dividing the output signal of the first light receiving element 21 before correction by the sum of the output signals of the two light receiving elements 21 and 22 before correction. Twice the first value and the value (second value) obtained by dividing the output signal of the second light receiving element 22 before correction by the sum of the output signals of the two light receiving elements 21 and 22 before correction. Is the value of When the incident angle of light changes from the height direction to the left and right, the incident area of the light varies, and the absolute values of the output signals S1 and S2 vary. The amount of variation is proportional to the incident angle of the light, and the incident angle is schematically represented by the first value and the second value. Therefore, as described above, by calculating (1 + ΔG2) S1 and calculating (1−ΔG2) S2, it is possible to obtain an output signal in which manufacturing variation is suppressed and it is difficult to depend on the incident angle of light. . Thereby, the amount of solar radiation can be detected.

  In the present embodiment, as shown in FIG. 1, an example in which a pair of light receiving elements 21 and 22 and a pair of openings 51 and 52 are arranged in the left-right direction is shown. However, it is only necessary that the shapes of the pair of light receiving elements 21 and 22 and the pair of openings 51 and 52 have a line-symmetric structure, and the respective arrangement positions are not limited to the above example. As shown in FIG. 4, the pair of light receiving elements 21 and 22 and the pair of openings 51 and 52 do not have to be shifted in the front-rear direction and aligned in the left-right direction. FIG. 4 is a plan view showing a modification of the optical sensor.

  In the present embodiment, an example in which the pair of light receiving elements 21 and 22 are formed on the semiconductor substrate 10 is shown. However, the number of pairs of light receiving elements 20 forming a pair may be two or more. For example, as shown in FIG. 5, light receiving elements 23 and 24 that are paired in the front-rear direction may be formed. FIG. 5 is a plan view showing a modification of the optical sensor.

  In the present embodiment, an example in which the light-transmitting film 30 is one layer and the light-shielding film 40 is one layer is shown. However, the number of layers of each of the light transmitting film 30 and the light shielding film 40 is not limited to the above example. For example, a configuration in which the light transmitting film 30 has two layers and the light shielding film 40 has two layers may be employed. According to this, since the multilayer light shielding film 40 is located between the pair of light receiving elements 21 and 22, light incident from a certain opening 50 is a light receiving element other than the light receiving element 20 corresponding to the opening 50. 20 is suppressed from entering. Thereby, it is suppressed that disturbance noise is included in the output signal of each light receiving element 20.

  In this embodiment, the example which the light shielding film 40 consists of a material which has light-shielding property and electroconductivity was shown. However, when the electronic elements formed on the semiconductor substrate 10 do not have to be electrically connected by the light shielding film 40, the light shielding film 40 may be formed of a material that absorbs light.

DESCRIPTION OF SYMBOLS 10 ... Semiconductor substrate 20 ... Light receiving element 30 ... Translucent film 40 ... Light shielding film 50 ... Opening 60 ... Correction | amendment part 100 ... Optical sensor

Claims (6)

A plurality of light receiving elements (20) are formed on the semiconductor substrate (10), and a light shielding film (30) is formed on the formation surface (10a) of the light receiving element (20) in the semiconductor substrate (10) via a light transmitting film (30). 40), a light-transmitting opening (50) is formed in the light shielding film (40), and the light sensor (20) receives light through the opening (50). Because
A pair of the light receiving elements (21, 22) having a line symmetrical relationship via a virtual straight line (VL) along one direction of the formation surface (10a) is formed on the semiconductor substrate (10),
A pair of openings (51, 52) having a line-symmetric relationship via the virtual straight line (VL) is formed in the light shielding film (40) corresponding to the pair of light receiving elements (21, 22). ,
A part of the projection surface of each of the pair of openings (51, 52) projected onto the formation surface (10a) along the height direction orthogonal to the formation surface (10a) corresponds to the corresponding light receiving element. It overlaps the light receiving surface,
Output signals output from the pair of light receiving elements (21, 22) when the light along the height direction is irradiated to the light receiving elements (21, 22) through the openings (51, 52). The pair of light receiving elements (21, 22) output when light along the height direction enters the light receiving elements (21, 22) through the openings (51, 52), respectively. as the output signal of coincide with each other, have a correction unit (60) for correcting the respective output signals,
Of the pair of light receiving elements (21, 22), the output signal of one of the light receiving elements (21) is S1, the other output signal is S2, and the light along the height direction is the opening (51, 52). Assuming that the output signal S1 when incident on the light receiving element (21, 21) via SV1 is SV1 and the output signal S2 is SV2, the correction unit (60) has the first correction number ΔG1 = (SV2−SV1) / (SV1 + SV2) is stored, and (1 + ΔG1) is multiplied by the output signal S1, and (1-ΔG1) is multiplied by the output signal S2, thereby correcting each output signal S1, S2. Sensor. A part of the projection surface protrudes from the light receiving surface in a direction perpendicular to the virtual straight line (VL) along the forming surface (10a), and the projection surface and the light receiving surface are on the forming surface (10a). the optical sensor of claim 1 in which the planar shape is characterized that you have forms a substantially convex shape formed on. It said light shielding film (40), the formed multilayer on transparent film (30), by the opening formed in each layer of the light shielding film (40) (50), the Rukoto elevation of the light is defined the optical sensor of claim 1 or claim 2, characterized. A method for manufacturing an optical sensor according to claim 1,
When light along the height direction enters the light receiving element (21, 22) through the opening (51, 52), one of the light receiving elements of the pair of light receiving elements (21, 22) is received. When the output signal of the device (21) SV1, the other output signal SV2, to calculate the first correction number .DELTA.G1 = a (SV2-SV1) / (SV1 + SV2), having a memory to keep storing step Rukoto the method of manufacturing an optical sensor you characterized. The pair of openings (51, 52) are symmetrical with respect to the virtual straight line (VL), and the pair of openings (51, 52) projected onto the formation surface (10a) along the height direction. A film forming step of forming the light-shielding film (40) and the light-transmitting film (30) on the formation surface (10a) such that a part of each projection surface overlaps the light-receiving surface of the corresponding light-receiving element. Have
In the film forming step, a part of the projection surface protrudes from the light receiving surface along the formation surface (10a) in a direction perpendicular to the virtual straight line (VL), and the projection surface and the light receiving surface are the optical sensor of claim 4 planar shape formed on the forming surface (10a) is to form a generally convex shape, characterized that you form the light shielding film (40) and said transparent film (30) Manufacturing method . In the film forming step, the light shielding film (40) is formed in multiple layers on the light transmitting film (30), and the elevation angle of light is defined by the opening (50) formed in the light shielding film (40) of each layer. the method of manufacturing an optical sensor according to claim 5, wherein to Rukoto.

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