JP2005317994A - Semiconductor photodetector device and electrical equipment equipped with the semiconductor photodetector device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light-receiving element capable of detecting the intensity of only visible light among received light, and electrical equipment equipped with the semiconductor light-receiving element. <P>SOLUTION: The semiconductor light-receiving element comprises a light-receiving region where optical energy of received light is converted into electrical energy, equipped with the pair of light-receiving elements having at least two light-receiving elements insulated from each other and an operational circuit that calculates the electrical signals output by each light-receiving element. The pair of light-receiving elements comprise a coloring light-receiving element which deposits resin with a dye or pigment on the first coating portion covering the first light-receiving region in light-receiving region, and non-colored light-receiving element which does not deposit the resin on the second coating portion covering the second light-receiving region. Alternatively, the pair of light-receiving elements comprise a coloring light-receiving element that includes die or pigment and non-colored light-receiving element that does not include die or pigment on the second coating portion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a semiconductor light-receiving device and an electrical apparatus including the semiconductor light-receiving device.

  Conventionally, there are electrical devices that change operation according to ambient brightness, for example, portable electrical devices that change display brightness according to ambient brightness, and lighting devices that switch power according to ambient brightness. is there. These electric devices are usually provided with a light receiving element for detecting the received light. As the light receiving element, a photodiode having a PN junction that converts received light into optical energy is used.

  In addition, when a photodiode is used to detect the illuminance of the received light, a special filter that transmits or reflects light of a specific wavelength on the light receiving unit such as a photodiode, for example, visibility correction A filter or the like was provided.

  There is also a light receiving element in which a protective film covering the surface of a photodiode chip is coated with a resin containing a predetermined dye.

  Conventionally, the brightness around the electrical equipment has been detected by using these light receiving elements.

  However, when a special filter is used, the overall size of the light receiving device increases, and the manufacturing cost of the light receiving device increases. In addition, in the case of a surface mount type, there is a problem that it is difficult to externally attach a filter because an element is mounted on a printed board and then heated by a reflow process.

  In addition, the method of coating a resin containing a dye on the protective film has a problem that there is no appropriate dye that sufficiently absorbs infrared light and transmits only visible light.

  Therefore, conventionally, an electric device that includes a light receiving device and whose operation is changed according to the ambient brightness does not perform a predetermined operation or malfunctions depending on the difference between the light of the fluorescent lamp and the light of the incandescent lamp. There was a thing.

  Accordingly, an object of the present invention is to provide a semiconductor light-receiving element that can detect the illuminance of only visible light in the received light and an electric device including the semiconductor light-receiving element.

  A semiconductor light-receiving device according to an embodiment of the present invention includes at least two light-receiving elements that each include a light-receiving region that converts optical energy of received light into electrical energy, and is insulated from each other, and each of the light-receiving elements And an arithmetic circuit for calculating an electrical signal output from the computer.

  By comparing the photoelectrons generated in one light receiving element of the semiconductor light receiving element and the semiconductor light receiving element according to the present invention with the photoelectrons generated in the other color light receiving elements, a predetermined value around the semiconductor light receiving element or the electric device is obtained. The illuminance of the light can be detected.

  In addition, the operation of the electric apparatus including the light receiving device according to the present invention can be reliably changed according to the ambient brightness, and does not malfunction due to the difference between the fluorescent light and the incandescent light.

  FIG. 1 is an enlarged plan view of a semiconductor light receiving device according to a first embodiment of the present invention. A light receiving unit 150 is provided in a part of the semiconductor substrate 110. The light receiving unit 150 is divided into two, and forms the stained light receiving element 120 and the unstained light receiving element 130 that are electrically insulated from each other. The stained light receiving element 120 and the unstained light receiving element 130 form one light receiving element pair.

  2A and 2B are schematic cross-sectional views along the line AA ′ of the embodiment in FIG. With reference to FIG. 2 and FIG. 1, the semiconductor light receiving device 100 according to the present embodiment will be described in more detail.

  A PN junction is formed on the semiconductor substrate 110 of the semiconductor light receiving device 100. This PN junction generates a photocurrent according to the energy of incident light.

  In the embodiment shown in FIG. 2A, the dyed light receiving element 120 of FIG. 1 has a light receiving region 170 on which light is incident, and the light receiving region 170 is covered with a covering portion 180. A resin 190 containing a dye or a pigment is deposited on the covering portion 180. On the other hand, the unstained light receiving element 130 also has a light receiving region 170 on which light is incident, and the light receiving region 170 is covered with a covering portion 180. However, the resin 190 containing a dye or a pigment is not deposited on the covering portion 180.

  The resin 190 in FIG. 2A is selectively formed by a CVD process. However, the present invention is not limited to the CVD method, and it may be applied by spin coating, ink jet printing, or other known methods.

  In the embodiment shown in FIG. 2B, the covering portion 181 that covers the light receiving region 170 of the dyed light receiving element 120 in FIG. 1 contains a dye or a pigment. On the other hand, the covering portion 182 that covers the light receiving region 170 of the unstained light receiving element 130 does not contain a dye or a pigment.

The cover portion 181 in FIG. 2B is selectively formed by a process such as CVD, separately from the manufacturing process of the cover portion 182. As a material for the covering portions 180, 181, and 182, SiO ₂ or the like is used. Further, as the material of the dye or pigment, a material having a small particle size is preferable. The covering portions 180, 181, and 182 are also used as a protective film for protecting the light receiving region 170 and the PN junction. Accordingly, the covering portion 181 is a film that blocks visible light, and is also a protective film that protects the light receiving region 170 and the PN junction.

  Although the embodiments according to FIGS. 2A and 2B differ in structure, both have a portion containing a dye or pigment on the dyed light receiving element 120. In the present embodiment, the dye or pigment absorbs visible light. Accordingly, only the infrared light of the light received by the dyed light receiving element 120 reaches the light receiving region 170 of the dyed light receiving element 120. On the other hand, almost all of the light received by the unstained light receiving element 130 reaches the light receiving region 170 of the unstained light receiving element 130.

  Since the stained light receiving element 120 and the unstained light receiving element 130 are electrically insulated, the photoelectrons generated at the PN junction portion of the stained light receiving element 120 and the photoelectrons generated at the PN junction portion of the unstained light receiving element 130 are independent of each other. Can be detected. The terminals 140 and 142 in FIG. 1 are electrically connected to the dyed light receiving element 120 and the undyed light receiving element 130, respectively. Accordingly, the terminal 140 and the terminal 142 can detect photoelectrons generated in the dyed light receiving element 120 and photoelectrons generated in the unstained light receiving element 130, respectively.

  The electrical signals detected by the terminals 140 and 142 are processed by the peripheral circuit region 160 other than the light receiving unit 150 on the surface of the semiconductor substrate 110.

According to the semiconductor light receiving device according to the present embodiment, the photocurrent generated by the infrared light among the light received by the light receiving unit 150 in the dyed light receiving element 120 can be detected, and the light receiving unit 150 received by the unstained light receiving element 130. The photocurrent generated by all of the light can be detected. Therefore, by comparing the photoelectrons generated in the dyed light receiving element 120 and the photoelectrons generated in the unstained light receiving element 130, the illuminance of visible light among the light received by the light receiving unit 150 can be detected. (See Figure 5)
The dye or pigment is not limited to one that absorbs visible light. Accordingly, a dye or pigment that absorbs light of a specific wavelength may be used.

  In addition, any of the embodiments shown in FIG. 2 (A) or FIG. 2 (B) may be used in the embodiments of FIGS.

  FIG. 3 is an enlarged plan view of a second embodiment of the semiconductor light receiving device according to the present invention, which is different from the embodiment of FIG. In the light receiving unit 250 of the semiconductor light receiving device 200 according to the present embodiment, a plurality of light receiving element pairs of the embodiment of FIG. 1 are reduced and arranged.

  A plurality of dyed light receiving elements 220 and a plurality of undyed light receiving elements 230 form a plurality of light receiving element pairs. The plurality of stained light receiving elements 220 are electrically connected in parallel by wirings 241, and the plurality of unstained light receiving elements 230 are electrically connected in parallel by wirings 243. On the other hand, electrical insulation is maintained between the dyed light receiving element 220 and the non-dyed light receiving element 230.

  The dyed light receiving element 220 and the unstained light receiving element 230 are arranged adjacent to each other while maintaining electrical insulation. That is, when both the dyed light receiving element 220 and the undyed light receiving element 230 are square, a checkered pattern is formed.

  The semiconductor light receiving device 200 can be viewed almost accurately even when the intensity or wavelength of light applied to a part of the light receiving unit 250 is different from the intensity or wavelength of light applied to another part of the light receiving unit 250. The illuminance of light can be detected.

  For example, when only the intensity of light irradiated to the light receiving region A in a part of the light receiving unit 250 is different, the photocurrent generated in the light receiving element pair in the light receiving region A is generated in the light receiving element pair in the other part of the light receiving unit 250. Different from photocurrent. However, since the light receiving area A includes the entire light receiving element pair of the dyed light receiving element 220 and the unstained light receiving element 230, the illuminance of visible light in the light receiving area A is generated in the dyed light receiving element 220 in the light receiving area A. It can be detected by the difference between the photocurrent and the photocurrent generated in the unstained light receiving element 230. Therefore, the illuminance of visible light of the entire light receiving unit 250 is accurately determined by the difference between the photocurrent generated in the dyed light receiving element 220 of the entire light receiving unit 250 and the photocurrent generated in the unstained light receiving element 230 of the entire light receiving unit 250. Can be detected.

  FIG. 4 is an enlarged plan view of a third embodiment of the semiconductor light-receiving device according to the present invention, which is different from the embodiments of FIGS. In the light receiving unit 350 of the semiconductor light receiving device 300, a plurality of light receiving element pairs are further reduced and arranged in a plurality of numbers than the light receiving element pairs in the embodiment of FIG.

  The stained light receiving element 320 and the unstained light receiving element 330 are arranged adjacent to each other while maintaining electrical insulation. That is, when both the dyed light receiving element 320 and the unstained light receiving element 330 are square, a checkered pattern is formed.

  In FIG. 4, wirings and terminals are omitted for easy understanding.

  In the semiconductor light receiving device 300, the light receiving unit 350 includes more light receiving element pairs than the light receiving element pairs included in the light receiving unit 250 of FIG. Therefore, the semiconductor light receiving device 300 can be used for semiconductor light even when the intensity or wavelength of light applied to a part of the light receiving unit 350 is different from the intensity or wavelength of light applied to another part of the light receiving unit 350. The illuminance of visible light can be detected more finely and more accurately than the light receiving device 200.

  The light receiving element pairs may be further reduced than the light receiving element pairs in the embodiment of FIG. 4 and a plurality of light receiving element pairs may be arranged. Thereby, the semiconductor light receiving device can detect the illuminance of visible light more finely and more accurately than the semiconductor light receiving device 300.

  FIG. 5 is a diagram showing an embodiment of a light receiving element and a peripheral circuit 500 for detecting a photocurrent included in the semiconductor light receiving device according to the present invention. In this example, the dyed light receiving element 120 and the undyed light receiving element 130 in the embodiment of FIG. 1 are used. Although the peripheral circuit 500 is included in the peripheral circuit region 160 (see FIG. 1), the peripheral circuit 500 is described between the dyed light receiving element 120 and the non-dyed light receiving element 130 for easy understanding.

The stained light receiving element 120 and the unstained light receiving element 130 respectively output a photocurrent I ₁₃₀ and a photocurrent I ₁₄₀ corresponding to the received light energy. A voltage V ₃ and a voltage V ₄ corresponding to the photocurrent I ₁₃₀ and the photocurrent I ₁₄₀ are generated by the resistors R ₁₃₀ and R ₁₄₀ having the same resistance value, respectively. The voltage V ₃ and the voltage V ₄ are input to a known differential amplifier circuit 510. The differential amplifier circuit 510 outputs a voltage V ₁₃₀ and a voltage V ₁₄₀ obtained by amplifying the voltage V ₃ and the voltage V ₄ . The difference between the photocurrent I ₁₃₀ and the photocurrent I ₁₄₀ can be calculated from the difference between the voltage V ₁₃₀ and the voltage V ₁₄₀ .

  Note that the present invention is not limited to the detection of the difference in photocurrent by the differential amplifier circuit, and other various operations may be executed using other circuits.

  FIG. 6 is a diagram showing an embodiment of an electric apparatus provided with a semiconductor optical passive device according to the present invention. FIG. 6 shows a main body 801, a display 802, a keyboard 803, a mouse 804, and a printer 805 of a computer 800. A semiconductor optical passive device 1000 is provided near the screen of the display 802. Accordingly, when the periphery of the display 802 is dark and the illuminance of visible light detected by the semiconductor optical passive device 1000 is below the reference value, the computer 800 can increase the output of the display 802 and increase the screen brightness. . Further, the keyboard 803 and other switches (not shown) may be turned on.

  On the other hand, when the periphery of the display 802 is bright and the illuminance of visible light detected by the semiconductor optical passive device 1000 is greater than or equal to the reference value, the computer 800 can weaken the output of the display 802 and reduce the screen brightness. . Further, the keyboard 803 and other switches may be turned off. It helps to save energy. In this embodiment, a desktop computer is shown, but it can be used in a notebook computer as well.

  In addition to the embodiment of FIG. 6, the semiconductor optical passive device can be deployed in various electrical devices.

  For example, the semiconductor optical passive device can be used for a portable electric device (not shown) equipped with a liquid crystal monitor such as a mobile phone or a mobile computer. By detecting the illuminance of ambient light, the semiconductor optical passive device deployed in mobile phones, etc., adjusts the LCD backlight to darken when the surroundings are bright, preventing the battery from being consumed more than necessary. be able to.

  In addition, by deploying the semiconductor optical passive device in an air conditioner (not shown), the semiconductor optical passive device detects the illuminance of the light around the air conditioner, and after a predetermined time after the air conditioner becomes dark, the air conditioner switches on the switch. It can also be turned off automatically.

  Also, by placing the semiconductor optical passive device in an electric pot (not shown), the semiconductor optical passive device detects the illuminance of light around the electric pot, and the electric pot is kept warm after the surrounding of the electric pot becomes dark The temperature can also be lowered automatically.

Also, by arranging the semiconductor light passive device in a fluorescent lamp (not shown), the semiconductor light passive device detects the illuminance of the light around the fluorescent lamp, and when the fluorescent light is dark, It can also be turned on automatically. On the other hand, when the surroundings of the fluorescent lamp become bright, the fluorescent lamp can be automatically turned off. Also, by disposing the semiconductor optical passive device in the refrigerator (not shown), the semiconductor optical passive device is installed in the refrigerator. When the illuminance of light is detected and the inside of the refrigerator becomes bright, the refrigerator can automatically release the air curtain so that the cool air is not missed.

  Also, by placing the semiconductor optical passive device on a television (not shown), the semiconductor optical passive device detects the illuminance of the ambient light of the television, and when the ambient light of the television becomes brighter, the television The brightness can be adjusted automatically.

  In addition, by deploying a semiconductor optical passive device in the camera (not shown), the semiconductor optical passive device detects the illuminance of the ambient light of the camera, and when the ambient of the camera becomes brighter, the camera It can also be adjusted automatically. Furthermore, the semiconductor optical passive device can be used for various other electric devices.

1 is an enlarged plan view of a first embodiment of a semiconductor light-receiving device according to the present invention. FIG. 2 is a schematic cross-sectional view taken along the line AA ′ of the embodiment in FIG. 1. The enlarged plan view of 2nd Embodiment of the semiconductor light-receiving device by this invention different from embodiment of FIG. FIG. 4 is an enlarged plan view of a third embodiment of a semiconductor light receiving device according to the present invention, which is different from the embodiment of FIGS. 1 and 3. The figure which showed embodiment of the peripheral circuit for detecting the light receiving element contained in the semiconductor light-receiving device by this invention and a photocurrent. The figure which showed embodiment of the electric equipment provided with the semiconductor optical passive device by this invention.

Explanation of symbols

100, 200, 300, 1000 Semiconductor light receiving device 110, 210, 310 Semiconductor substrate 120, 220, 320 Dye light receiving element 130, 230, 330 Unstained light receiving element 140, 142, 240, 242, 340, 342 Terminals 150, 250, 350 Light Receiving Unit 160 Peripheral Circuit Area 170 Light Receiving Area 180 Covering Section 190 Resin 500 Peripheral Circuit 510 Differential Amplifier Circuit 800 Computer

Claims (1)

At least two light receiving elements each including a light receiving region that converts optical energy of received light into electrical energy and insulated from each other;
An arithmetic circuit for calculating an electrical signal output from each of the light receiving elements;
A semiconductor light receiving device.

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