WO2009133716A1 - ダイオードおよびそれを備えた光センサ回路並びに表示装置 - Google Patents
ダイオードおよびそれを備えた光センサ回路並びに表示装置 Download PDFInfo
- Publication number
- WO2009133716A1 WO2009133716A1 PCT/JP2009/050371 JP2009050371W WO2009133716A1 WO 2009133716 A1 WO2009133716 A1 WO 2009133716A1 JP 2009050371 W JP2009050371 W JP 2009050371W WO 2009133716 A1 WO2009133716 A1 WO 2009133716A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- diode
- photodiode
- semiconductor region
- diodes
- channel
- Prior art date
Links
- 239000000758 substrate Substances 0.000 claims abstract description 51
- 239000004065 semiconductor Substances 0.000 claims description 214
- 230000003287 optical effect Effects 0.000 claims description 66
- 239000003990 capacitor Substances 0.000 claims description 39
- 238000001514 detection method Methods 0.000 claims description 33
- 230000008859 change Effects 0.000 claims description 32
- 239000012535 impurity Substances 0.000 claims description 32
- 230000010354 integration Effects 0.000 description 29
- 239000010408 film Substances 0.000 description 15
- 238000005468 ion implantation Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 11
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 10
- 229910052710 silicon Inorganic materials 0.000 description 10
- 239000010703 silicon Substances 0.000 description 10
- 230000007423 decrease Effects 0.000 description 9
- 238000004519 manufacturing process Methods 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- 239000011159 matrix material Substances 0.000 description 8
- 230000008569 process Effects 0.000 description 6
- 238000004904 shortening Methods 0.000 description 6
- 239000004973 liquid crystal related substance Substances 0.000 description 5
- 230000035945 sensitivity Effects 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical group [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000007935 neutral effect Effects 0.000 description 3
- 230000003071 parasitic effect Effects 0.000 description 3
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 3
- 229920005591 polysilicon Polymers 0.000 description 3
- 230000003321 amplification Effects 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 230000006798 recombination Effects 0.000 description 2
- 238000005215 recombination Methods 0.000 description 2
- 230000009291 secondary effect Effects 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 101100214491 Solanum lycopersicum TFT3 gene Proteins 0.000 description 1
- 229910021417 amorphous silicon Inorganic materials 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 239000002772 conduction electron Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000002513 implantation Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 230000004044 response Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
- H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
- H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
- H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
- H01L31/105—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier being of the PIN type
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/10—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void
- G01J1/16—Photometry, e.g. photographic exposure meter by comparison with reference light or electric value provisionally void using electric radiation detectors
- G01J1/1626—Arrangements with two photodetectors, the signals of which are compared
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
- G01J1/44—Electric circuits
- G01J1/46—Electric circuits using a capacitor
Definitions
- the present invention basically relates to a diode structure, and more particularly to a diode structure that can eliminate individual differences in characteristics, a photosensor circuit including the diode, and a display device including the photosensor circuit. Is.
- a plurality of photosensors are arranged at regular intervals in a display device having a photosensor in a frame region around the display screen or a display panel having a plurality of pixels, and the photosensors are assigned to corresponding pixels.
- a display device provided inside has been developed. By utilizing the light amount detection function of the optical sensor, these display devices may have various functions such as a backlight dimming function, a touch panel function, an OCR function for character recognition, or a security function such as fingerprint authentication. it can.
- a PIN photodiode is used as an optical sensor included in the display device as described above.
- the structure of the PIN photodiode includes a vertical structure in which a P layer, an I layer, and an N layer are stacked in this order on a substrate, and a horizontal type in which the P layer, the I layer, and the N layer are arranged in the in-plane direction on the substrate ( Lateral) structure.
- the P layer is a semiconductor layer having a high P-type impurity concentration
- the I layer is an intrinsic semiconductor layer or a semiconductor layer having a low impurity concentration
- the N layer is a semiconductor layer having a high N-type impurity concentration.
- the lateral structure is a structure in which the P layer, the I layer, and the N layer do not overlap each other, and as a result, the parasitic capacitance between the layers is reduced, resulting in a sensing speed that is faster than the vertical structure.
- the lateral structure has an advantage that it can be manufactured by using the same process as a TFT having a configuration such as PNP, PIP, NPN, or NIN.
- FIG. 17 shows an optical sensor formed by a lateral structure PIN photodiode (see Patent Document 1 below).
- the optical sensor 81 of FIG. 17 includes a P layer 82, an I layer 83, and an N layer 84 formed on the silicon film 85.
- the P layer 82, the I layer 83, and the N layer 84 are sequentially arranged along the in-plane direction of the silicon film 85.
- the silicon film 85 is formed on a glass substrate 90 that serves as a base of the active matrix substrate.
- the electrode pattern 88 is connected to the P layer 82 via the contact plug 86, and the electrode pattern 89 is connected to the N layer 84 via the contact plug 87.
- a mask having a pattern for forming the P layer 82 is applied to the silicon film 85, for example, and ion implantation of P-type impurities such as boron is performed, while the N layer 84 is formed. Then, another mask having a pattern for forming n is applied, and ion implantation of N-type impurities such as phosphorus and arsenic is performed.
- the length W of the long side where the I layer 83 is in contact with the P layer 82 and the N layer 84 is better.
- the relationship shown in FIG. 18 is established between the short side length L of the I layer 83 (hereinafter referred to as the channel length L) and the current magnitude I.
- the first problem that it is difficult to manufacture a PIN photodiode having stable characteristics, and the channel width W must be increased in order to increase the light receiving sensitivity. Therefore, there arises a second problem that the occupied area becomes large when the PIN photodiode is formed on the substrate.
- the first problem is that by providing such an optical sensor 81, the various functions given to the display device vary from device to device.
- the second problem is that in the case of a display device in which such a photosensor 81 is incorporated in a pixel, the area occupied by the photosensor 81 in the pixel is increased, and thus a high-definition display device with a high pixel density is manufactured. This makes it difficult, or causes the optical sensor 81 to lower the aperture ratio of the pixel. This causes a negative effect such that the display screen becomes a dark display device instead of having the various functions.
- the channel length L of the I layer 83 is L ⁇ L.
- the design current I0 with respect to the design value L0 cannot be obtained, corresponding to L0 ⁇ L.
- a reduced current I0- ⁇ I is obtained. That is, the variation in the channel length L causes a variation in the detection value based on the current generated by the optical sensor 81.
- the design current I0 is not only decreased, but may increase.
- the increase occurs, for example, when the mask at the time of forming the N layer 84 is shifted in the opposite direction to the above example and the channel length L becomes larger than the design value L0.
- the shift of the mask for forming the P layer also causes variations in the channel length L independently of the shift of the mask for forming the N layer.
- the present invention has been made in view of the above-described problems, and an object of the present invention is to stabilize characteristics in a diode having a lateral structure in which an intrinsic semiconductor region is sandwiched between impurity semiconductor regions, and in a substrate.
- An object of the present invention is to provide a display device that can be stabilized.
- the diode according to the present invention (1) a first semiconductor region having a relatively high impurity concentration and exhibiting a first polarity; a channel region which is a semiconductor region having a relatively low impurity concentration; A diode that is in contact with each other and is arranged in order along a specific direction included in the plane of the substrate is defined as a reference diode, and a channel width of the reference diode is defined as a reference diode.
- the channel length is a length of a channel region formed between the first semiconductor region and the second semiconductor region in a direction parallel to the specific direction included in the plane of the substrate, In other words, it is the length from the boundary between the first semiconductor region and the channel region to the boundary between the channel region and the second semiconductor region.
- the channel width is the line length at the boundary between the first semiconductor region and the channel region, and is also the line length at the boundary between the channel region and the second semiconductor region.
- the magnitude of the photocurrent of the photodiode has a maximum value with respect to the channel length, and the photocurrent increases in the range of the channel length from 0 to the maximum value. It shows a change that current decreases.
- the IV characteristic representing the relationship between the diode current and the voltage applied to the diode changes linearly with respect to the range that is linearly changing with respect to the channel length or the range that can be regarded as linearly changing. It cannot be regarded as being, but has a non-linearly changing range.
- the diode of the present invention has a channel width W1 smaller than the channel width W and substantially equal to each other without changing the size of each semiconductor region in the direction parallel to the channel length of the reference diode.
- the diode of the present invention has a range that the channel width W1 and the channel length can take.
- the electrical connection is appropriately selected from a parallel connection, a series connection, and a combination of these two connections.
- the layout on the substrate related to the arrangement of the even number of diodes configured as described above is devised as follows. That is, the arrangement directions of the respective semiconductor regions constituting the plurality of diodes are all parallel to the specific direction, and the mutual positional relationship of the respective semiconductor regions is a line-symmetrical or point-symmetrical position as a whole. It is arranged on the substrate so as to be related.
- the specific direction is equal to the direction parallel to the channel length.
- the channel length of a diode in which a mask used when forming the first semiconductor region by ion implantation of impurities is located on one side of a line-symmetrical or point-symmetrical positional relationship, for example.
- the mask is also shifted in the same first direction for the diode (referred to as diode ⁇ ) located on the other side of the line-symmetrical or point-symmetrical positional relationship.
- the first direction is, for example, a direction from the first semiconductor region to the channel region for the diode ⁇ , and is in a line symmetric or point symmetric positional relationship for the diode ⁇ .
- the direction is toward the first semiconductor region.
- the mask for forming the first semiconductor region is shifted in the direction from the channel region toward the first semiconductor region, so that the channel length is increased.
- the length of the channel length of the diode ⁇ is equal to the length of the diode ⁇ of which the channel length is shortened.
- the shortening of the channel length in the diode ⁇ is offset by the extension of the channel length in the diode ⁇ .
- the channel obtained by averaging the shortened channel length of the diode ⁇ and the elongated channel length of the diode ⁇ The length is equal to the channel length of the reference diode.
- the IV of the diode depends on the degree of mask displacement. Although another problem of characteristic variation occurs, the present invention is not so, and two conflicting characteristic changes cancel each other out. As already described, this is ensured by the condition that “the plurality of diodes are electrically connected to each other, thereby performing the same function as the reference diode”.
- the channel width W1 of each diode is smaller than the channel width W of the reference diode, the region occupied by the diode on the substrate can be narrowed in a direction parallel to the channel width.
- the channel length of each channel region of the N diodes is such that the IV characteristic representing the relationship between the diode current and the voltage applied to the diode is linear with respect to the change in channel length. It is selected from a range that can be considered to change.
- the IV characteristics of the diode that can be considered to change linearly cancel each other out between the diode ⁇ and the diode ⁇ .
- the above configuration provides a design guideline for the channel length for the diode of the present invention to perform the same function as the reference diode.
- the channel width W1 can be regarded as a linear change of the IV characteristics of the diode with respect to the change of the channel width. Then, for example, when the channel width W1 is W / N, the IV characteristics of the N diodes constituting the diode of the present invention are linear relations between the channel width W1 and the IV characteristics of the diode. 1 / N of the IV characteristic of the reference diode.
- each channel width W1 may be set to W / N.
- N diodes having the channel width W1 of W / N can be connected in parallel to each other.
- the channel width W1 is selected from a range in which the IV characteristics of the diode can be considered to change linearly with respect to the change in channel width.
- N 2
- the diode of the present invention performs the same function as the reference diode.
- the channel width W1 is selected from a range in which the IV characteristics of the diode can be considered to change linearly with respect to the change in the channel width, and N diodes are electrically connected in parallel, the channel width W1 And N are inversely related.
- the diode according to the present invention includes a first set in which N / 2 diodes are electrically connected in series, and a second set in which N / 2 diodes are electrically connected in series.
- the second set and the second set may be electrically connected in parallel so that the channel width W1 is W / 2.
- the channel width W1 is selected from a range in which the IV characteristics of the diode can be considered to change linearly with respect to the change in channel width.
- the voltage applied to one diode is the voltage applied to the entire N / 2 diodes.
- the value obtained by multiplying the number connected in series, that is, the reciprocal of N / 2 is reduced to 2 / N. Therefore, based on the linear relationship between the IV characteristics of the diodes and the channel width, the IV characteristics when N / 2 diodes are electrically connected in series constitute N / 2 diodes. This is the same as the IV characteristic of one diode.
- the channel width W1 is set to W / 2.
- the above configuration has two diodes connected in parallel with the channel width W1 set to W / 2. However, this is the same as when the IV characteristics of the reference diode are the same.
- the N is a diode including a configuration of 2, in other words, is configured by at least two diodes, and the two diodes are used as a first diode and a second diode.
- the first diode and the second diode are formed in one Si island, and the first semiconductor region or the second semiconductor region is the first diode and the second diode. May be shared.
- the first semiconductor region is shared by the first diode and the second diode. Then, if the respective second semiconductor regions are electrically connected, the first diode and the second diode are connected in parallel, and the IV characteristics of the diode are affected by changes in channel length and channel width. On the other hand, by appropriately selecting the channel length and the channel width from each range that can be considered to change linearly, a diode that performs the same function as the reference diode can be obtained.
- the arrangement directions of the semiconductor regions constituting the plurality of diodes are all parallel to the specific direction, and the mutual positional relationship of the semiconductor regions is generally line-symmetric or point-symmetric.
- the first diode in the first diode, the second semiconductor region, the channel region, and the first semiconductor region are arranged along the specific direction.
- the second diode has a configuration in which the shared first semiconductor region, channel region, and second semiconductor region are arranged in this order along the specific direction. .
- the first diode and the second semiconductor region are formed in a single Si island. Two diodes can be built. It is therefore advantageous to reduce the area of the diode that occupies on the substrate.
- the diode includes a configuration in which N is 4, in other words, is configured by at least four diodes.
- the four diodes are arranged in the order in which the four diodes are arranged in the specific direction.
- a third diode and a fourth diode, and the first semiconductor region is shared by the second diode and the third diode
- the second diode and the fourth diode are structurally equivalent, and the fourth diode is arranged in series with the third diode along the specific direction.
- the first diode and the third diode are structurally equivalent, and the first diode is arranged in series with the second diode along the specific direction.
- the first diode and the second diode share the second semiconductor region
- the third diode and the fourth diode also share the second semiconductor region
- the first semiconductor regions are electrically connected to each other
- the second semiconductor regions are also electrically connected to each other. It may be a form.
- the first to fourth diodes share either the first semiconductor region or the second semiconductor region with adjacent diodes. is doing. Therefore, four diodes can be built in a single Si island. It is therefore advantageous to reduce the area of the diode that occupies on the substrate.
- the arrangement order of the semiconductor regions (first and second semiconductor regions and channel region) in the second diode and the fourth diode is the same.
- the arrangement order of the semiconductor regions in the first diode and the third diode is the same.
- the arrangement of the semiconductor regions in the second diode and the third diode is reverse, that is, symmetrical, and the arrangement of the semiconductor regions in the first diode and the fourth diode. Is also in reverse order, ie symmetric.
- the configuration described above is as follows: “The arrangement directions of the semiconductor regions constituting the plurality of diodes are all parallel to the specific direction, and the positional relationship between the semiconductor regions is linear as a whole. The above-mentioned condition of “arranged on the substrate so as to have a symmetrical or point-symmetrical positional relationship” is satisfied.
- the configurations of (6) and (7) above mean that the first to fourth diodes are electrically connected in parallel. Therefore, as already described, by appropriately selecting the channel length and channel width from each range in which the IV characteristics of the diode can be considered to change linearly with changes in the channel length and channel width, the same function as the reference diode is achieved. A diode is obtained.
- the optical sensor circuit according to the present invention is characterized in that any one of the above-described diodes is used as a photodiode.
- the arrangement of the semiconductor regions on the substrate is arranged in line symmetry or point symmetry, and functions in the same manner as the reference diode. Therefore, an optical sensor circuit using the diode as a photodiode can have a stable light receiving characteristic that is not affected by the displacement of the mask in the manufacturing process.
- the photosensor circuit according to the present invention may employ a layout in which the channel width is reduced with respect to the layout on the substrate. it can.
- the photosensor circuit when the photosensor circuit is incorporated in a pixel of a liquid crystal display device, a plurality of diodes can be dispersed in different pixels one by one, and with respect to the vertical width of the pixel.
- the ratio occupied by the channel width may be smaller than the ratio occupied by the channel width of the reference diode.
- a display device is characterized in that the photosensor circuit according to claim 9 is incorporated in at least one of a plurality of pixels constituting a display screen.
- the light receiving characteristics of the optical sensor circuit are stable without variation depending on the display device, so that the backlight dimming function using the function of the optical sensor, the touch panel function, etc. are stable.
- a display device can be provided.
- the display device includes one photosensor circuit for each of a predetermined number of adjacent pixels among the plurality of pixels, and the diode constituting one of the photosensor circuits. And other elements are distributed and arranged in the predetermined number of pixels.
- the predetermined number is an integer of 2 or more. Accordingly, it is possible to provide a display device in which various functions such as a backlight dimming function using a function of an optical sensor, a touch panel function, an OCR function for character recognition, or a security function such as fingerprint authentication are stable.
- a display device can be provided.
- a combination of a configuration described in a certain claim and a configuration described in another claim is limited to a combination of the configuration described in the claim cited in the claim.
- combinations with configurations described in the claims not cited in the focused claims are possible.
- FIG. 2 is a circuit diagram showing a configuration of an optical sensor circuit provided, and an explanatory diagram showing a problem that a channel region decreases.
- It is a schematic block diagram which shows the structure of the display apparatus which concerns on this invention.
- It is a circuit diagram which shows the structure of the circuit for a display which comprises the pixel circuit provided in 1 pixel of the said display apparatus, and an optical sensor circuit. It is a timing chart which shows operation
- FIG. 9 is a schematic plan view showing an example of a layout of an optical sensor circuit in which the photodiode of FIG. 8A is built in one pixel.
- FIG. 9 is a schematic plan view showing an example of a layout of an optical sensor circuit in which the photodiode of FIG. 8B is built in one pixel.
- It is a circuit diagram which shows the example of the optical sensor circuit using N photodiodes connected in parallel.
- It is explanatory drawing which shows the example which comprised the group which formed two photodiodes in one Si island, and comprised two or more sets in parallel.
- FIG. 9 is a schematic plan view showing an example of a layout of an optical sensor circuit in which the photodiode of FIG. 8A is built in one pixel.
- FIG. 9 is a schematic plan view showing an example of a layout of an optical sensor circuit in which the photodiode of FIG. 8B is built in one pixel.
- It is a circuit diagram which shows the example of the optical sensor
- FIG. 4 is a circuit diagram showing an example in which two sets of a plurality of photodiodes connected in series are connected in parallel to form a photodiode and applied to an optical sensor circuit. It is explanatory drawing which shows the example which lays out four photodiodes linearly in one Si island, and comprises a photodiode by connecting in parallel.
- FIG. 16 is a circuit diagram illustrating a configuration of an optical sensor circuit using the photodiode of FIG. 15. It is a typical top view which shows an example of the layout of the circuit for a display which comprises the pixel circuit provided in 1 pixel of the conventional display apparatus, and an optical sensor circuit. It is a graph which shows the characteristic curve showing the relationship between the photoelectric current which a photodiode receives and generate
- FIG. 1 (a) and 1 (b) are examples of an optical sensor circuit having the same function.
- FIG. 1 (a) is an optical sensor circuit using the diode of the present invention, and
- FIG. ) Shows an optical sensor circuit using a conventional diode.
- (Reference diode) 1B has a relatively high impurity concentration, and a P (first polarity) type semiconductor region 5a (first semiconductor region) and an intrinsic semiconductor region (relative impurity concentration).
- a channel region 5b which is a low semiconductor region, and an N (opposite polarity with respect to the first polarity) type semiconductor region 5c (second semiconductor region) having a relatively high impurity concentration are in contact with each other and the substrate It is the structure arranged in order along the specific direction contained in the surface.
- the photodiode 5 functions in the same manner as the combination of the photodiodes 1 and 2 in FIG. 1A (the diode of the present invention), and serves as a reference channel width for the photodiodes 1 and 2. W and channel length L. Therefore, the photodiode 5 in FIG. 1B is hereinafter referred to as a reference diode 5.
- the specific direction is a direction in which one impurity semiconductor region, a channel region, and the other impurity semiconductor region constituting the diode are arranged.
- the diode of the present invention includes N diodes that are even numbers of 2 or more, and one impurity semiconductor region, a channel region, and the other impurity semiconductor region that constitute each diode are included. All the arrangement directions are aligned in parallel with the specific direction.
- the specific direction is, for example, parallel to the row direction, orthogonal to the column direction, and parallel to the row direction, which will be described later. It is parallel to the reset signal line 8 or row selection signal line 9 and is orthogonal to the power supply line 6 or output signal line 7 parallel to the column direction.
- the specific direction may be determined in any direction on the substrate as long as the layout relationship with other wirings or elements is not considered.
- the reference diode 5 generates a photocurrent having an intensity proportional to the channel width W (corresponding to the reference channel width W) and the channel length L when the received light intensity is the same. That is, the light receiving characteristics of the reference diode 5 (IV characteristics representing the relationship between the diode current and the voltage applied to the diode) and the channel width W and the channel length L have a linear relationship. Or, in other words, the channel width W and the channel length L are selected from each range showing a linear change or a change that can be regarded as linear with respect to the IV characteristic.
- the channel length L of the reference diode 5 is set to L0 in FIG. 18, the channel length L0 is included in a range in which the photocurrent and the channel length can be regarded as linearly changing.
- the channel length Lp is clearly not included in the range in which the photocurrent and the channel length can be considered to change linearly.
- the channel length L may be selected from a range of 0 ⁇ L ⁇ Lp or may be selected from a range of Lp ⁇ L.
- the photocurrent increases when the channel length L decreases, and when the channel length L increases, the photocurrent increases when the channel length L is selected from the former range. Decrease.
- the photosensor circuit of FIG. 1A includes two photodiodes 1 and photodiodes 2.
- a P-type semiconductor region 1a, a channel region 1b that is an intrinsic semiconductor region, and an N-type semiconductor region 1c are in contact with each other and are arranged in order along the specific direction.
- the N-type semiconductor region 2 a, the channel region 2 b that is an intrinsic semiconductor region, and the P-type semiconductor region 2 c are in contact with each other and are sequentially arranged along the specific direction. Yes.
- each of the regions 1a, 1b, 1c, 2a, 2b, 2c in the direction parallel to the specific direction is equal to the size of the corresponding region 5a, 5b, 5c of the reference diode 5 in the direction parallel to the specific direction. It is the same.
- the channel width of the photodiode 1 and the photodiode 2 satisfies the condition that the channel width W of the reference diode 5 is smaller than the channel width W. More specifically, the channel widths of the photodiode 1 and the photodiode 2 under the condition that the IV characteristic of the reference diode 5 and the channel width W and the channel length L have a relationship that can be regarded as linear. Are set to W / 2, respectively.
- the photodiode 1 and the photodiode 2 are configured such that the N-type semiconductor region 1 c and the N-type semiconductor region 2 a having the same polarity are electrically connected, and The P-type semiconductor region 1a and the P-type semiconductor region 2c having the same polarity are electrically connected. That is, the photodiode 1 and the photodiode 2 are electrically connected in parallel.
- each of the photodiodes 1 and 2 is half the photocurrent (intensity I) generated by the reference diode 5 for the same received light intensity. A photocurrent with an intensity of (I / 2) is generated.
- the photodiodes 1 and 2 connected in parallel generate a photocurrent having the same intensity as the photocurrent (intensity I) generated by the reference diode 5. That is, the photodiodes 1 and 2 function in the same manner as the reference diode 5.
- the arrangement directions of the regions 1a, 1b, 1c, 2a, 2b, 2c are all parallel to the specific direction, and the positional relationship between the regions 1a, 1b, 1c, 2a, 2b, 2c Are arranged on the substrate so as to have a line-symmetrical or point-symmetrical positional relationship as a whole.
- the arrangement of the regions 1a, 1b, and 1c and the arrangement of the regions 2a, 2b, and 2c are line symmetric (mirror symmetry) in the case of FIG.
- a bias direction (a direction from the P-type semiconductor region 1a toward the N-type semiconductor region 1c) when a forward bias is applied to the photodiode 1
- a bias when a forward bias is applied to the photodiode 2 The direction (the direction from the P-type semiconductor region 2c toward the N-type semiconductor region 2a) is opposite.
- the photodiode 1 and the photodiode 2 need only have a layout parallel to the specific direction, and need not be linearly arranged on the same line as shown in FIG. For example, even if the photodiode 1 and the photodiode 2 are arranged on two parallel lines that are parallel to each other in the row direction but are spaced apart from each other, the arrangement relationship is point-symmetric. Is satisfied.
- the reference diode 5 is always provided. It is possible to stably manufacture a diode having the same IV characteristics.
- the channel length L of the photodiode 1 is shortened by ⁇ L and becomes La. Even so, in the photodiode 2, the channel length L increases by ⁇ L and becomes Lb. That is, according to the present invention, even if the mask is misaligned, the shortening of the channel length L in the photodiode 1 is offset by the extension of the channel length L in the photodiode 2. That is, the average channel length of the shortened channel length La of the photodiode 1 and the elongated channel length Lb of the photodiode 2 is equal to the original channel length L.
- the photocurrent increases in the photodiode 2 as much as the photocurrent decreases in the photodiode 1.
- the magnitude of the photocurrent generated by the photodiodes 1 and 2 is the same as the magnitude of the photocurrent generated by the reference diode 5 regardless of the mask misalignment.
- the optical sensor circuit using the photodiode having the configuration of the present invention does not have individual differences in IV characteristics (light receiving characteristics), and can uniformly have desired IV characteristics.
- the display device incorporates a photosensor circuit using photodiodes having a symmetrical layout as described above.
- the display device 10 includes a transparent substrate 12 on which all the circuit elements constituting various drivers and pixels are integrated.
- the material of the transparent substrate 12 is, for example, glass.
- “Monolithically formed” means that a device is formed directly on a glass substrate by a physical process and / or a chemical process, and does not include mounting a semiconductor circuit on the glass substrate. is there.
- the display device 10 includes an active matrix region 13, a source driver 14, a gate driver 15, a sensor row driver 16, and a sensor reading driver 17.
- source signal lines and scanning signal lines are formed in a matrix, and there are known elements constituting the pixel, such as a switching element and a pixel electrode for driving the pixel, corresponding to the intersection position of the two lines. Is formed. Further, an optical sensor circuit is provided in each pixel.
- the source driver 14 supplies a display signal via a source signal line
- the gate driver 15 supplies a pixel selection signal to each pixel via a scanning signal line.
- the sensor row driver 16 selects and drives the photosensor circuit for each row, and the sensor reading driver 17 applies a power supply voltage VDD having a constant potential to the photosensor circuit and reads a photodetection signal from the photosensor circuit.
- FIG. 3 shows a circuit configuration of the pixel circuit 18 provided in one of the pixels constituting the active matrix region 13.
- the pixel circuit 18 includes a display circuit 18a and a photosensor circuit 18b. Note that the display circuit 18a is provided for each pixel, whereas the photosensor circuit 18b is not necessarily provided for all pixels, and the necessary pixels (in accordance with the resolution required for light detection). For example, it may be provided for every predetermined number of pixels).
- the display circuit 18 a is formed at or near each intersection of the source signal line 21 and the gate signal line 22 arranged in rows and columns (column direction and row direction), and includes a thin film transistor (hereinafter referred to as TFT) 23,
- TFT thin film transistor
- the liquid crystal capacitor 25 is configured between the pixel electrode connected to one end and the common electrode 24 facing the pixel electrode, and the auxiliary capacitor 27 is connected between the common signal line 26.
- the optical sensor circuit 18b is configured as a 1T (abbreviation of transistor) type circuit using only one transistor.
- TFT: M1 (corresponding to TFT3 shown in FIG. 1) functions as a source follower transistor (voltage follower transistor).
- the drain of the TFT M1 is connected to the power supply line 28 (corresponding to the power supply line 6 shown in FIG. 1), and the source is connected to the output signal line 29 (corresponding to the output signal line 7 shown in FIG. 1). Yes.
- the power supply line 28 and the output signal line 29 are connected to the sensor reading driver 17, and the power supply voltage VDD is applied to the power supply line 28 from the sensor reading driver 17.
- the gate of the TFT M1 is connected to the cathode (third electrode) of the photodiodes 1 and 2 equivalent to the reference diode 5 (hereinafter, the photodiodes 1 and 2 are collectively referred to as the photodiode 30).
- One end (second electrode) of an integration capacitor 31 (corresponding to the integration capacitor 4 in FIG. 1) connected in series with the photodiode 30 is connected.
- the anode (fourth electrode) of the photodiode 30 is connected to a reset signal line (initialization signal input line) 32 to which a reset signal RST is sent from the sensor row driver 16, and the other end (first electrode) of the integration capacitor 31. ) Is connected to a row selection signal line (selection signal input line) 33 to which a row selection signal RWS is sent.
- the row selection signal RWS has a role of selecting a specific row of the photosensor circuits arranged in a matrix and outputting a detection signal from the photosensor circuit in the specific row.
- the silicon film for forming the photodiode 30 is formed at the same time as the silicon film for forming an active element such as TFT: M1 is formed on the transparent substrate 12.
- Each of the regions 1a, 1b, 1c, 2a, 2b, and 2c includes P that constitutes the active element and circuit elements included in the source driver 14, the gate driver 15, the sensor row driver 16, and the sensor reading driver 17. It is formed using a step of forming a type or N type semiconductor region (ion implantation step).
- the N-type semiconductor region 1c and the N-type semiconductor region 2a can be formed by an N-type semiconductor region forming process (ion implantation process) of an active element.
- the N-type semiconductor region of the active element is formed by multiple ion implantations having different implantation conditions from those of the N-type semiconductor regions 1c and 2a, the N-type semiconductor region is selected from the multiple ion implantation steps. The optimum ion implantation process for the formation of 1c and 2a is selected.
- the channel regions 1b and 2b are formed so as to be electrically more neutral than the adjacent impurity semiconductor regions.
- the above-described mask is provided in the formation region of the channel regions 1b and 2b, or the formed silicon film is electrically
- the channel regions 1b and 2b can be formed by performing ion implantation also in the formation regions of the channel regions 1b and 2b.
- the silicon film can be formed of an amorphous silicon film, a polysilicon film, a continuous grain boundary crystal silicon (CGS) film, or the like.
- the silicon film is preferably formed of a polysilicon film or a CGS film, and particularly preferably formed of a CGS film having the highest electron mobility.
- a high level reset signal RST is sent from the sensor row driver 16 to the reset signal line 32 in order to reset the gate potential VINT of the TFT: M1.
- the forward bias is applied to the photodiode 30 during the reset period (t1 to t2), so that the integration capacitor 31 is charged, the gate potential VINT gradually rises, and finally reaches the initialization potential (V DDR ). To do.
- the gate potential VINT is obtained by subtracting the forward voltage drop (V F ) in the photodiode 30 and the voltage drop ( ⁇ V RST ) caused by the parasitic capacitance of the photodiode 30 from the initialization potential (V DDR ). Value.
- the light detection result reading period that is, the detection signal reading period (t3 to t4) is entered, and then the high-level row is connected to the other end of the integration capacitor 31 from the sensor row driver 16 via the row selection signal line 33.
- a selection signal RWS is applied.
- the gate potential VINT is pushed up through the integration capacitor 31, so that the gate potential VINT is set to a potential obtained by adding the high level potential of the row selection signal RWS to the detection potential (for example, the potential V1 shown in FIG. 4). Become.
- the potential V1 shown in FIG. 4 corresponds to the bright state when the photodiode 30 receives strong light and the gate potential VINT falls to the lowest level at t3.
- the threshold voltage for turning on the TFT: M1 is exceeded, so that the TFT: M1 is turned on.
- a voltage controlled at an amplification factor according to the level of the gate potential VINT that is, according to the light intensity, is detected as a detection signal (for example, VPIX in the bright state shown in FIG. 4) from the source of the TFT: M1.
- the signal is output and sent to the sensor reading driver 17 via the output signal line 29.
- the gate potential VINT is pushed up through the integration capacitor 31, so that the gate potential VINT is set to the initialization potential to the high level of the row selection signal RWS. Is substantially equal to the added potential (for example, the potential V2 shown in FIG. 4).
- the detection signal for example, the dark state VPIX shown in FIG. 4
- the TFT M1 shows the maximum level.
- a detection signal having a level corresponding to the intensity of light received by the photodiode 30 is generated, and the detection signal is generated in each pixel in which the photosensor circuit 18b is built. Therefore, by using the light of the backlight that the display device 10 shown in FIG. 2 has as a light source for display, the coordinates on the display screen can be read with respect to the detection target arranged close to the display screen of the display device 10. Detection operations such as character reading or fingerprint reading can be performed.
- the optical sensor circuit 18b is configured by an extremely small number of elements as compared with a conventional CMOS photosensor circuit described later with reference to FIG. For this reason, since the area occupied by the photosensor circuit 18b in the pixel is small, the 1T photosensor circuit 18b is very advantageous in increasing the aperture ratio of the pixel. Further, if the number of elements is small, the self-parasitic capacitance of the optical sensor circuit 18b is reduced, so that the response speed of the detection operation is increased, and the problem that the dynamic range is reduced by pulling in the parasitic capacitance can be improved. it can.
- the light detection accuracy varies from display device to display device. There is no problem, and any display device can obtain a desired detection characteristic and can provide an excellent display device that performs bright display.
- FIG. 6 is an enlarged plan view schematically showing the vicinity of the optical sensor circuit 18b in one pixel composed of red, green, blue (RGB) three-color sub-pixels 35R, 35G, and 35B.
- RGB red, green, blue
- the sub-pixels 35R, 35G, and 35B are each provided with the display circuit 18a.
- the source signal line 21 extends in the column direction between the sub-pixels 35R, 35G, and 35B adjacent to each other in the row direction, and supplies display signals of the respective colors to the TFTs 23 (FIG. 3) that are components of the respective display circuits 18a. To do.
- the source signal line 21 provided between the sub-pixels 35R and 35G also serves as the power supply line 28, and the source signal line 21 provided between the sub-pixels 35G and 35B35G is It also serves as the output signal line 29.
- the optical sensor circuit 18b is provided by using one end side region in the column direction of the sub-pixels 35R, 35G, and 35B.
- the one end side region is partitioned by the reset signal line 32 and the row selection signal line 33 orthogonal to the source signal line 21. Note that the reset signal line 32 and the row selection signal line 33 are provided at regular intervals in the column direction.
- the TFT: M1 that is a component of the optical sensor circuit 18b is provided in the one end side region of the subpixel 35G, and the photodiodes 1 and 2 as the photodiode 30 are respectively subpixels 35R. And the one end side region of the sub-pixel 35B.
- a line 36a for connecting the gate of the TFT M1 and the cathode (N layer) of the photodiode 1 is provided, for example, below the source signal line 21 between the sub-pixels 35R and 35G.
- An extending portion 37a that is a part of the selection signal line 33 extends.
- An integration capacitor 31a which is a part of the integration capacitor 31 is formed by the overlap of the line 36a and the extending portion 37a.
- a line 36b that connects the gate of the TFT M1 and the cathode (N layer) of the photodiode 2 is provided, for example, below the source signal line 21 between the sub-pixels 35G and 35B.
- An extending portion 37 b that is a part of the row selection signal line 33 extends.
- An integration capacitor 31b which is a part of the integration capacitor 31 is formed by the overlap of the line 36b and the extending portion 37b.
- the lines 36a and 36b can be formed of Si, for example.
- the drain of the TFT: M1 is connected to the source signal line 21 also serving as the power supply line 28 via the contact portion 38a, and the source of the TFT: M1 is connected to the source signal line 21 also serving as the output signal line 29 and the contact portion 38b. Connected through. Further, the anode (P layer) of the photodiode 1 is connected to the reset signal line 32 via the contact portion 38c, and the anode (P layer) of the photodiode 2 is also connected to the reset signal line 32 via the contact portion 38d. It is connected.
- the photosensor circuit 18b is composed of very few components compared to the conventional CMOS photosensor circuit shown in FIG. 7A, which contributes to an improvement in the aperture ratio. It can be seen that bright display is possible.
- Photosensor elements such as thin-film photodiodes made of low-temperature polysilicon (LPS) have relatively high sensitivity to blue light and relatively low sensitivity to red light. ing. Because of this characteristic, placing the photo sensor element on a red pixel has the demerit that the dynamic range is narrowed due to poor sensitivity, but it has the merit that the signal quality is improved because the stray light that wraps around the pixel is not read. . On the other hand, placing a photosensor element on a blue pixel has the advantage of widening the dynamic range because of its high sensitivity, but it has the disadvantage of reducing signal quality because it tends to pick up stray light.
- LPS low-temperature polysilicon
- the photo sensor elements are arranged in both the red pixel and the blue pixel, by combining the above advantages and disadvantages, the photo sensor has a good balance between the dynamic range and the signal quality. ing.
- FIG. 7 shows a variation of the optical sensor circuit 18b.
- the photodiode 62 can be replaced with an even number of photodiodes arranged symmetrically of the present invention.
- FIG. 7C shows a 1T-type optical sensor circuit having the same configuration as the optical sensor circuit 18b already described with reference to FIGS. That is, the constituent elements of the optical sensor circuit 18b shown in FIG. 3 correspond to the constituent elements of the optical sensor circuit shown in FIG. 7C as follows.
- FIG. 7A shows a 3T-type conventional CMOS photosensor circuit including three TFTs 64, 65 and 66.
- a photodiode 62 and an integration capacitor 63 are connected in parallel.
- the anode of the photodiode 62 and one end of the integration capacitor 63 are grounded, while the cathode of the photodiode 62 and the other end of the integration capacitor 63 are connected to the gate of the TFT 65. And connected to the source of the TFT 64.
- the gate of the TFT 64 is connected to the reset signal line 32 that supplies the reset signal RST, and the drain is connected to the power supply line 28 that supplies the power supply voltage VDD.
- the source of the TFT 65 and the output signal line 29 are connected via the drain and source of the TFT 66.
- the gate of the TFT 66 is connected to the row selection signal line 33 that supplies the row selection signal RWS.
- the integration capacitor 63 is charged by the power supply voltage VDD and holds the gate potential VINT of the TFT 65 at the initialization potential. At this time, a reverse bias is applied to the photodiode 62.
- the TFT 66 is turned on, and the voltage corresponding to the gate potential VINT of the TFT 65, that is, the maximum in the dark state where the light receiving intensity is 0. In the bright state where the received light intensity is sufficiently strong, a voltage indicating the minimum value is output from the source of the TFT 65 to the output signal line 29 via the TFT 66.
- FIG. 7B shows a 2T-type photosensor circuit that uses two transistors, reduces the number of components by one from the 3T-type photosensor circuit, and improves the aperture ratio.
- the TFT 64 that is on / off controlled by the reset signal RST is omitted from the 3T photosensor circuit, and one electrode (second electrode) of the integration capacitor 63 is connected to the gate of the TFT 65 and the photodiode 62.
- the other electrode (first electrode) of the integration capacitor 63 is connected to a power supply line for supplying the power supply voltage VDD.
- the reset signal RST is supplied to the anode (fourth electrode) of the photodiode 62 as in the case of the 1T-type photodiode 62.
- the 2T photosensor circuit is (1) Two drain-source conductive paths are formed in series between the power supply line 6 that supplies the power supply voltage VDD and the output signal line 7 that outputs a photodetection signal of the photosensor circuit. Connected TFT 65 and TFT 66; (2) the row selection signal line 9 for supplying the row selection signal RWS to the gate of the TFT 66 during the reading period of the light detection signal; (3) It changes between a first voltage that applies a forward bias to the photodiode 62 during the reset period of the photodiode 62 and a second voltage that applies a reverse bias to the photodiode 62 during the light detection period.
- the reset signal line 8 for supplying the reset signal RST, (4)
- the cathode of the photodiode 62 is connected to the gate of the TFT 65 and is connected to the power supply line 6 via the integration capacitor 63.
- a high level reset signal RST equal to the power supply voltage VDD is applied to the anode of the photodiode 62 in order to reset the gate potential VINT of the TFT 65.
- a forward bias is applied to the photodiode 62 during the reset period.
- the gate potential VINT is an initialization potential obtained by subtracting the forward voltage drop of the photodiode 62 from the power supply voltage VDD.
- the cathode potential of the photodiode 62 becomes higher than the anode potential, so that the photodiode 62 is reverse-biased. .
- a photocurrent due to reverse bias flows to the photodiode 62 in accordance with the intensity of light.
- the gate potential VINT is a voltage obtained by subtracting the voltage applied to the integration capacitor 31 from the power supply voltage VDD. That is, the gate potential VINT falls according to the light intensity.
- the detection signal reading period starts, and then the high-level row selection signal RWS is applied to the gate of the TFT 66.
- the TFT 66 is turned on, so that a voltage controlled with an amplification factor corresponding to the level of the gate potential VINT, that is, the light intensity, is output from the source of the TFT 66 as a detection signal.
- the 2T photosensor circuit is configured with a smaller number of elements than the 3T photosensor circuit, which is advantageous in increasing the aperture ratio of the pixel.
- the photodiodes 1 and 2 are formed on separate Si islands. In contrast, in the present embodiment, two photodiodes are formed in one Si island.
- FIG. 8A shows a photodiode 40 equivalent to the photodiodes 1 and 2 shown in FIG.
- the N-type semiconductor region 1c and the N-type semiconductor region 2a are separate regions and are electrically connected, whereas in the photodiode 40, the N-type semiconductor region 1c and the N-type semiconductor region 2a are shared by the photodiodes 1 and 2.
- the positional relationship between the semiconductor regions is a line-symmetrical or point-symmetrical positional relationship as a whole. It can be placed on a substrate and can act the same as a reference diode.
- the area of the photodiode occupying the substrate can be reduced as compared with the case where the two photodiodes are formed on different Si islands. 35B or either of the sub-pixels 35B), it is advantageous for downsizing the pixel or improving the aperture ratio.
- FIG. 8B shows a photodiode 41 having a configuration in which two photodiodes share a P-type semiconductor region.
- the arrangement order of the P-type semiconductor region and the N-type semiconductor region is opposite to each other, but the reset signal RST is supplied to the P-type semiconductor region constituting the anode to constitute the cathode. Since the wiring is made so that the integration capacitor is connected to the N-type semiconductor region, the functions are exactly the same.
- FIG. 9 shows a circuit diagram in which the photodiodes 1 and 2 shown in FIG.
- the optical sensor circuit shown in FIG. (1) TFT 3 that forms a drain-source conductive path between the power supply line 6 that supplies the power supply voltage VDD and the output signal line 7 that outputs a photodetection signal of the photosensor circuit; and (2) photodetection.
- the row selection signal line 9 for supplying the row selection signal RWS for raising the gate potential of the TFT 3 through a capacitor during a signal reading period; (3)
- the reset signal that changes between a first voltage that applies a forward bias to the photodiode 41 during a reset period of the photodiode 41 and a second voltage that applies a reverse bias to the photodiode 41 during a light detection period.
- a reset signal line 8 for supplying RST.
- the configuration shown in FIG. (4) The cathode of the photodiode 41 is connected to the conductive path connecting the row selection signal line 9 and the gate of the TFT 3 via the first capacitor CINT as the capacitor, while the anode is the reset signal line 8.
- the cathode is connected to the conductive path connecting the row selection signal line 9 and the gate of the TFT 3 via the first photodiode connected to the second capacitor CINT and the second capacitor CINT as the capacitor, while the anode is the reset signal.
- a second photodiode connected to the line 8.
- FIG. 10 shows an example of a layout of an optical sensor circuit in which the photodiode 40 is built in one pixel (for example, any one of the sub-pixels 35R, 35G, and 35B).
- a TFT whose drain is connected to the source signal line 21 which also serves as the power supply line 28 and whose source is connected to the source signal line 21 which also serves as the output signal line 29; the N-type semiconductor region of the photodiode 40 is located at the gate of M1. It is connected.
- the electrode 42 extends from the N-type semiconductor region of the photodiode 40 to the row selection signal line 33 that runs parallel to the specific direction in which the semiconductor regions of the photodiode 40 are arranged. As a result, the integration capacitor 31 is formed.
- connection wiring is formed so as to straddle the row selection signal line 33 from the reset signal line 32 running parallel to the row selection signal line 33 to the P-type semiconductor regions at both ends of the photodiode 40.
- FIG. 11 shows an example of a layout of an optical sensor circuit in which the photodiode 41 is built in one pixel (for example, any one of the sub-pixels 35R, 35G, and 35B).
- the drain is connected to the source signal line 21 that also serves as the power supply line 28, and the source is connected to the source signal line 21 that also serves as the output signal line 29, as in FIG.
- a bifurcated electrode 43 extends from the gate and is connected to the N-type semiconductor regions at both ends of the photodiode 41.
- the electrode 43 extends to the row selection signal line 33 through the N-type semiconductor region, and forms an integration capacitor 31 as a result of forming an overlap with the row selection signal line 33.
- connection wiring is formed so as to straddle the row selection signal line 33 from the reset signal line 32 to the P-type semiconductor region of the photodiode 40.
- the photodiode of this embodiment has a configuration in which N photodiodes that are an even number of 4 or more are connected in parallel. That is, the cathodes of the N photodiodes are electrically connected, and the anodes are electrically connected. As in the photosensor circuit shown in FIG. 1A, each cathode is connected to the gate of the TFT 3, and the reset signal RST is input to each anode.
- each of the N photodiodes The channel length L is the same as that of the diode 5, and the channel width is 1 / N of the channel width W of the reference diode 5, that is, W / N.
- the N photodiodes having the channel width and the channel length set in this manner are electrically connected in parallel, and thus, the same function as the reference diode 5 is achieved.
- N photodiodes As shown by a frame B in FIG. 12, two photodiodes form one set, and a plurality of sets (N / 2 sets) of photodiodes are arranged in the vertical direction.
- the two photodiodes forming one set have bias directions opposite to each other, and the cathodes face each other.
- the arrangement directions of the semiconductor regions constituting the N photodiodes are all parallel to the specific direction, and the mutual positional relationship of the semiconductor regions is line-symmetric or point-symmetric as a whole. It arrange
- FIG. 13 shows an example in which two sets in which two photodiodes are formed in one Si island are prepared and the two sets of photodiodes are connected in parallel as shown in FIG.
- the relationship with the specific direction is exactly the same for the N photodiodes constituting the photodiode shown in FIG. That is, the arrangement directions of the semiconductor regions constituting the N photodiodes are all parallel to the specific direction, and the mutual positional relationship of the semiconductor regions is generally line symmetric or point symmetric. It arrange
- a first group in which N / 2 photodiodes are electrically connected in series and a second group (frame in which N / 2 photodiodes are electrically connected in series). D), and the first set and the second set are electrically connected in parallel.
- the cathodes of the photodiodes located at each end of the first set and the second set are connected to conductive paths that connect the row selection signal line 9 and the gate of the TFT 3 via the integration capacitor 4, respectively.
- the anodes of the photodiodes located at the other ends of the first group and the second group are respectively connected to the reset signal line 8.
- the channel width is selected from a range in which the IV characteristics of the photodiode can be considered to change linearly with respect to the change in the channel width, all the channel widths of the N photodiodes are W / 2. It is. The reason for this is as follows.
- the voltage applied to one photodiode is connected in series to the voltage applied to the entire N / 2 photodiodes. It becomes a value obtained by multiplying the number, that is, the inverse of N / 2, and decreases to 2 / N. Therefore, the IV characteristic when N / 2 photodiodes are electrically connected in series is not different from the IV characteristic of one diode constituting the N / 2 photodiodes.
- the first set and the second set are electrically connected in parallel, and the channel width is set to W / 2. This is the same as when two diodes having a channel width of W / 2 are connected in parallel and have the same IV characteristics as the reference diode.
- the photodiode shown in FIG. 15 has a configuration advantageous for reducing the area of the photodiode occupying on the substrate by forming four photodiodes in one Si island.
- the configuration is as follows (1) to (7).
- the four photodiodes are defined as first, second, third, and fourth photodiodes 51, 52, 53, and 54 in the order in which they are arranged along the specific direction, and, for example, a P-type semiconductor region A (first semiconductor region) 55 is shared by the second photodiode 52 and the third photodiode 53.
- the second photodiode 52 and the fourth photodiode 54 are structurally equivalent, and the fourth photodiode 54 is arranged along the specific direction with the third photodiode 53. Are connected in series.
- the first photodiode 51 and the third photodiode 53 are structurally equivalent, and the first photodiode 51 is arranged along the specific direction with the second photodiode 52. Are connected in series.
- the first photodiode 51 and the second photodiode 52 share an N-type semiconductor region (second semiconductor region) 56.
- the third photodiode 53 and the fourth photodiode 54 also share another N-type semiconductor region (second semiconductor region) 57.
- the P-type semiconductor region 55 and the P-type semiconductor regions 58 and 59 of the first and fourth photodiodes 51 and 54 are electrically connected to each other. It is connected to the.
- the N-type semiconductor regions 56 and 57 are also electrically connected to each other.
- the reset signal RST is supplied to the P-type semiconductor regions 55, 58 and 59, while the N-type semiconductor region 56, 57 is connected to the gate of the TFT 3 and one electrode of the integration capacitor 4.
- the arrangement order of the semiconductor regions in the second photodiode 52 and the fourth photodiode 54 is the same, and according to the configuration of (3), the first photodiode
- the arrangement order of the semiconductor regions in 51 and the third photodiode 53 is the same.
- the arrangement of the semiconductor regions in the second photodiode 52 and the third photodiode 53 is reverse, that is, symmetrical, and the first photodiode 51 and the fourth photodiode are symmetrical.
- the semiconductor regions in the diode 54 are also arranged in reverse order, that is, symmetrical.
- the configuration described above is as follows: “The arrangement directions of the semiconductor regions constituting the plurality of photodiodes are all parallel to the specific direction, and the mutual positional relationship of the semiconductor regions is as a whole. The above-mentioned condition of “arranged on the substrate so as to have a line-symmetrical or point-symmetrical positional relationship” is satisfied.
- the configurations of (6) and (7) above mean that the first to fourth photodiodes 51 to 54 are electrically connected in parallel. Therefore, when the channel width is selected from a range in which the IV characteristics of the photodiode can be considered to change linearly with respect to the change in channel width, the channel length is set to L and the channel width is set to W. By selecting / 4, a photodiode that functions in the same manner as the reference diode 5 is obtained.
- FIG. 16 is an example in which four photodiodes are connected in parallel.
- the N-type semiconductor regions are connected to each other to form a P-type. If the semiconductor regions are connected to each other, the number N is not limited to 4, and can be an even number of 4 or more.
- the “intrinsic semiconductor region” may be a region that is electrically more neutral than the adjacent semiconductor region having the first polarity and the semiconductor region having the second polarity.
- the “intrinsic semiconductor region” is preferably a region containing no impurities or a region having the same conduction electron density and hole density.
- the diode of the present invention can be applied to other types of semiconductor elements such as TFTs.
- the channel width and the channel length can be appropriately selected between the selected channel width and channel length and characteristics, as in the diode of the present invention.
- the element is such that a linear relationship or a relationship that can be regarded as a linear relationship is established.
- Such a semiconductor element can be specified as follows.
- These semiconductors include at least a first semiconductor region having a relatively high impurity concentration, a channel region that is a semiconductor region having a relatively low impurity concentration, and a second semiconductor region having a relatively high impurity concentration.
- the semiconductor element arranged in order along a specific direction included in the plane of the substrate is a reference semiconductor element, and the channel width of the reference semiconductor element is W.
- the channel width is smaller than the channel width W and N equal to two or more even numbers having the same channel width W1
- the direction of arrangement of the semiconductor regions constituting each of the plurality of semiconductor elements is all parallel to the specific direction, and the positional relationship between the semiconductor regions as a whole is a line-symmetrical or point-symmetrical positional relationship.
- the semiconductor element having the above asymmetric structure is, for example, a TFT whose channel length is defined by an n ⁇ region and a gate end. More specifically, such a TFT corresponds to a TFT having a one-sided GOLD structure in which an LDD region is provided only on the drain side, for example, among TFTs having a GOLD structure.
- the GOLD structure refers to a structure in which the gate electrode is not only opposed to the channel region, but is further opposed so that the gate electrode overlaps the LDD region.
- the display device of the present invention may be a display device including an active matrix substrate, and may be not only a liquid crystal display device but also an EL display device.
- the diode according to the present invention can also be configured as follows. That is, the first semiconductor region having a relatively high impurity concentration and exhibiting the first polarity, the channel region being a semiconductor region having a relatively low impurity concentration, and the first polarity having a relatively high impurity concentration.
- a second semiconductor region having a polarity opposite to that of the first diode is arranged in contact with each other and arranged in a permutation in the in-plane direction of the substrate, and has a size substantially equal to each semiconductor region of the first diode
- a second diode having each semiconductor region is symmetrically disposed on the substrate so that the bias direction of the first diode and the bias direction of the second diode are opposite to each other;
- the first diode and the second diode are electrically connected in parallel, and the first diode or the second diode has a function equivalent to that of a diode whose channel width is doubled. Ord.
- the second diode when the first semiconductor region, the channel region, and the second semiconductor region are arranged in this order in the in-plane direction of the substrate, According to the condition that “the first diode bias direction and the second diode bias direction are symmetrically arranged on the substrate so as to be opposite to each other”, the second diode The second semiconductor region, the channel region, and the first semiconductor region are arranged in this order along the same direction as the arrangement direction of the respective semiconductor regions of the first diode from the side closer to the diode. It becomes the composition which is.
- the two first semiconductor regions are electrically connected to each other, and the two second semiconductor regions are connected. They are also electrically connected.
- the mask used when forming the first semiconductor region by ion implantation of impurities is shifted, for example, in the first direction to shorten the channel length of the first diode. Also for the second diode, the mask shifts in the same first direction.
- the first direction is a direction from the first semiconductor region to the channel region for the first diode, and a direction from the channel region to the first semiconductor region for the second diode. is there.
- the channel length of the second diode is increased.
- a relationship is established in which the length of the channel length of the second diode is equal to the length of the channel length of the first diode.
- the shortening of the channel length in the first diode is offset by the extension of the channel length in the second diode.
- the IV of the diode depends on the degree of mask displacement. Although another problem of characteristic variation occurs, the present invention is not so, and two conflicting characteristic changes cancel each other out.
- the diode when used as a photodiode, the magnitude of the photocurrent generated by the diode by light reception is always proportional to the channel width, while if the channel length range is appropriately selected, It is also almost proportional to the channel length.
- the above-mentioned condition “acts equivalently to a diode in which the channel width of the first diode or the second diode is doubled” is the range of the channel length in which the IV characteristic of the diode is proportional to the channel length. This means that the configuration is appropriately selected.
- each of the first diode and the second diode is halved compared to a diode whose channel width is doubled, so that the region occupied by the diode in the substrate is in a direction parallel to the channel width. Can be narrowed.
- the diode according to the present invention has a relatively high impurity concentration and a first semiconductor region that exhibits the first polarity, and a channel region that is a semiconductor region that has a relatively low impurity concentration.
- a diode in which a second semiconductor region having a high impurity concentration and a polarity opposite to the first polarity is in contact with each other and arranged in order along a specific direction included in the plane of the substrate is a reference diode
- the channel width of the reference diode is W
- the channel width is smaller than the channel width W and equal to each other without changing the size of each semiconductor region in the direction parallel to the channel length of the reference diode.
- N diodes which are two or more even numbers, and each of the semiconductor regions constituting each of the plurality of diodes is parallel to the specific direction.
- the respective semiconductor regions are arranged on the substrate so that the mutual positional relationship of the respective semiconductor regions is a line-symmetrical or point-symmetrical positional relationship as a whole, and the plurality of diodes are electrically connected to each other.
- the configuration is equivalent to that of the reference diode.
- the mask for forming the first semiconductor region or the mask for forming the second semiconductor region is independently displaced, it always functions as the reference diode. It is possible to manufacture a diode having stable characteristics.
- the photosensor circuit according to the present invention has a configuration in which any of the above-described diodes is used as a photodiode.
- the photosensor circuit according to the present invention can have a stable light receiving characteristic that is not affected by the positional deviation of the mask in the manufacturing process.
- the photosensor circuit is incorporated in a pixel of a liquid crystal display device. Then, there is an effect that a secondary effect such as improving the aperture ratio of the pixel can be obtained.
- the display device has a configuration in which the photosensor circuit is incorporated in at least one of a plurality of pixels constituting the display screen.
- the present invention relates to a semiconductor element in which a linear relationship or a relationship that can be regarded as a linear relationship is established between channel width and channel length and characteristics, an electronic circuit using the semiconductor element, and an apparatus including the electronic circuit Can be applied to.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Electromagnetism (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Light Receiving Elements (AREA)
- Solid State Image Pick-Up Elements (AREA)
- Transforming Light Signals Into Electric Signals (AREA)
Abstract
Description
(1)相対的に不純物濃度が高く、第1の極性を示す第1の半導体領域と、相対的に不純物濃度の低い半導体領域であるチャネル領域と、相対的に不純物濃度が高く、第1の極性とは逆極性を示す第2の半導体領域とが、互いに接しており、かつ基板の面内に含まれる特定方向に沿って順に配列されたダイオードを基準ダイオードとし、その基準ダイオードのチャネル幅をWとしたとき、
(2)基準ダイオードのチャネル長に平行な上記特定方向の各半導体領域のサイズを変えずに、チャネル幅が上記チャネル幅Wより小さく、かつ互いに実質的に等しいチャネル幅W1を備えた2以上の偶数であるN個のダイオードを備え、
(3)上記N個のダイオードをそれぞれ構成する各半導体領域の配列の方向が、全て上記特定方向に平行であり、かつ、上記各半導体領域の互いの位置関係が、全体として線対称または点対称の位置関係となるように上記基板上に配置され、
(4)上記N個のダイオードが互いに電気的に接続されていることによって、上記基準ダイオードと同等の働きをすることを特徴とする。
(1)上記Nが4の構成を含むダイオードであり、言い換えれば、少なくとも4個のダイオードによって構成されており、当該4個のダイオードを、上記特定方向に沿って並んだ順に第1、第2、第3および第4のダイオードとし、かつ、上記第1の半導体領域が、上記第2のダイオードおよび第3のダイオードによって共有されている場合であって、
(2)上記第2のダイオードと上記第4のダイオードとは構成的に等価であり、上記第4のダイオードは、上記特定方向に沿って、上記第3のダイオードに対し直列接続されて配置され、
(3)上記第1のダイオードと上記第3のダイオードとは構成的に等価であり、上記第1のダイオードは、上記特定方向に沿って、上記第2のダイオードに対し直列接続されて配置され、
(4)上記第1のダイオードおよび第2のダイオードは、上記第2の半導体領域を共有し、
(5)上記第3のダイオードおよび第4のダイオードもまた、上記第2の半導体領域を共有し、
(6)上記第1の半導体領域同士が相互に電気的に接続され、
(7)上記第2の半導体領域同士もまた相互に電気的に接続されている、
という形態でもよい。
1a P型半導体領域
1b チャネル領域
1c N型半導体領域
2 フォトダイオード(N個のダイオードの1つ、第2のダイオード)
2a N型半導体領域
2b チャネル領域
2c P型半導体領域
3 TFT(その他の素子)
4 積分容量(その他の素子)
5 基準ダイオード
5a P型半導体領域(第1の半導体領域)
5b チャネル領域
5c N型半導体領域(第2の半導体領域)
10 表示装置
18b 光センサ回路
31 積分容量(その他の素子)
35R 副画素
35G 副画素
35B 副画素
40 フォトダイオード
41 フォトダイオード
51 第1のフォトダイオード
52 第2のフォトダイオード
53 第3のフォトダイオード
54 第4のフォトダイオード
C 枠囲み(ダイオードを直列接続した第1の組)
D 枠囲み(ダイオードを直列接続した第2の組)
L チャネル長
M1 TFT(その他の素子)
W チャネル幅(基準のチャネル幅)
本発明の一実施形態について図を参照しながら説明すれば、以下の通りである。
なお、以下で参照する各図は、説明の便宜上、本発明の一実施形態の構成部材のうち、本発明を説明するために必要な主要部材のみを簡略化して示したものである。また、各図中の部材の寸法は、実際の構成部材の寸法及び各部材の寸法比率等を忠実に表したものではない。このことは、後述する他の実施形態についても同様である。
図1の(b)のフォトダイオード5は、相対的に不純物濃度が高く、P(第1の極性)型半導体領域5a(第1の半導体領域)と、真性半導体領域(相対的に不純物濃度の低い半導体領域)であるチャネル領域5bと、相対的に不純物濃度が高いN(第1の極性に対し逆極性)型半導体領域5c(第2の半導体領域)とが、互いに接しており、かつ基板の面内に含まれる特定方向に沿って順に配列された構成である。
一方、図1の(a)の光センサ回路は、2個のフォトダイオード1およびフォトダイオード2を備えている。フォトダイオード1においては、P型半導体領域1aと、真性半導体領域であるチャネル領域1bと、N型半導体領域1cとが、互いに接しており、かつ上記特定方向に沿って順に配列されている。
次に、フォトダイオード1,2を構成する各領域1a,1b,1c,2a,2b,2cの、基板上におけるレイアウト(配置関係)について説明する。
本発明に係る表示装置は、上記のように対称的なレイアウトを持つフォトダイオードを使用した光センサ回路を内蔵している。
本実施の形態において、上記フォトダイオード30を形成するためのシリコン膜は、TFT:M1などのアクティブ素子を形成するためのシリコン膜を透明基板12上に形成するのと同時に形成されている。また、上記各領域1a,1b,1c,2a,2b,2cは、上記アクティブ素子や、上記ソースドライバ14、ゲートドライバ15、センサ行ドライバ16およびセンサ読取ドライバ17に含まれる回路素子を構成するP型またはN型の半導体領域の形成工程(イオン注入工程)を利用して形成されている。
次に、図4を参照して、光センサ回路18bの動作を説明する。
まず、TFT:M1のゲート電位VINTをリセットするために、センサ行ドライバ16からリセット信号線32にハイレベルのリセット信号RSTが送られる。これにより、リセット期間(t1~t2)において、フォトダイオード30に順方向バイアスがかかるので、積分容量31が充電され、ゲート電位VINTは徐々に立ち上がり、最終的に初期化電位(VDDR)に到達する。
一方、上記光検出期間(t2~t3)において、フォトダイオード30に光が照射されない場合には、フォトダイオード30に光電流が発生しないため、ゲート電位VINTは、初期化電位をほぼ保持し続ける。実際には、わずかにリーク電流が生じるため、ゲート電位VINTは、初期化電位より若干低い検出電位になる。
上記光センサ回路18bをフルカラー表示を行う液晶表示装置の画素内に設けたときの素子レイアウトの一例について、図6を参照して説明する。
図7に、光センサ回路18bのヴァリエーションを示す。図7の(a)~(c)に示す光センサ回路61のいずれにおいても、フォトダイオード62を、本発明の対称的に配置された偶数個のフォトダイオードで置き換えることができる。
積分容量31 ---積分容量63
TFT:M1 ---TFT65(ソースフォロワトランジスタ)
(光センサ回路のヴァリエーション;3T方式)
一方、図7の(a)は、3つのTFT64,65,66を備えた3T方式の従来のCMOS光センサ回路である。フォトダイオード62と積分容量63とが並列に接続され、フォトダイオード62のアノードと積分容量63の一端とは接地される一方、フォトダイオード62のカソードと積分容量63の他端とは、TFT65のゲートに接続されるとともに、TFT64のソースに接続されている。
次に、図7の(b)は、トランジスタを2つ用い、3T方式の光センサ回路より構成要素を1つ減らし、開口率の向上を図った2T方式の光センサ回路を示している。
(1)電源電圧VDDを供給する上記電源供給線6と、光センサ回路の光検出信号を出力する出力信号線7との間に、2つのドレインソース導電路を直列に形成するように、直列接続されたTFT65およびTFT66と、
(2)上記光検出信号の読取期間中に、上記TFT66のゲートに上記行選択信号RWSを供給する上記行選択信号線9と、
(3)上記フォトダイオード62のリセット期間中に、上記フォトダイオード62に順方向バイアスをかける第1電圧と、光検出期間中に、上記フォトダイオード62に逆バイアスをかける第2電圧とに変化する上記リセット信号RSTを供給する上記リセット信号線8とを備え、
(4)上記フォトダイオード62のカソードが、上記TFT65のゲートに接続されているとともに、積分容量63を介して上記電源供給線6に接続されている。
まず、TFT65のゲート電位VINTをリセットするために、電源電圧VDDに等しいハイレベルのリセット信号RSTがフォトダイオード62のアノードに印加される。これにより、リセット期間において、フォトダイオード62に順方向バイアスがかかる。ゲート電位VINTは、電源電圧VDDからフォトダイオード62の順方向電圧降下分を差し引いた初期化電位になる。
本発明の他の実施形態について図を参照しながら説明すれば、以下の通りである。なお、説明の便宜上、前記実施の形態に登場した構成要素と同等の構成要素には、同じ記号を付し、重複した説明を省略する。このことは、後述する他の実施形態についても同様である。
前記実施の形態1では、図6に示したとおり、フォトダイオード1,2を別々のSiアイランドに形成していた。これに対し、本実施の形態では、2つのフォトダイオードが1つのSiアイランドの中に形成されている。
図8の(b)は、2つのフォトダイオードが、P型半導体領域を共有した構成を持つフォトダイオード41を示している。
(1)上記電源電圧VDDを供給する電源供給線6と、光センサ回路の光検出信号を出力する出力信号線7との間に、ドレインソース導電路を形成するTFT3と、(2)光検出信号の読取期間中に、TFT3のゲートの電位を容量を介して突き上げる前記行選択信号RWSを供給する前記行選択信号線9と、
(3)フォトダイオード41のリセット期間中に、フォトダイオード41に順方向バイアスをかける第1電圧と、光検出期間中に、フォトダイオード41に逆バイアスをかける第2電圧とに変化する前記リセット信号RSTを供給するリセット信号線8とを備えている。
(4)上記フォトダイオード41は、上記容量としての第1の容量CINTを介して行選択信号線9とTFT3のゲートとを接続する導電路にカソードが接続される一方、アノードがリセット信号線8に接続された第1のフォトダイオードと、上記容量としての第2の容量CINTを介して行選択信号線9とTFT3のゲートとを接続する導電路にカソードが接続される一方、アノードがリセット信号線8に接続された第2のフォトダイオードとを備えている。
図10は、フォトダイオード40を1つの画素(例えば、上記副画素35R,35G,35Bのいずれか)に内蔵させた光センサ回路のレイアウトの一例を示している。
図11は、フォトダイオード41を1つの画素(例えば、上記副画素35R,35G,35Bのいずれか)に内蔵させた光センサ回路のレイアウトの一例を示している。
本発明のさらに他の実施形態について図を参照しながら説明すれば、以下の通りである。
本発明のさらに他の実施形態について図を参照しながら説明すれば、以下の通りである。
本発明のさらに他の実施形態について図を参照しながら説明すれば、以下の通りである。
基準半導体素子のチャネル長に平行な上記特定方向の各半導体領域のサイズを変えずに、チャネル幅が上記チャネル幅Wより小さく、かつ互いに等しいチャネル幅W1を備えた2以上の偶数であるN個の半導体素子を備え、
上記複数の半導体素子をそれぞれ構成する各半導体領域の配列の方向が、全て上記特定方向に平行であり、かつ、上記各半導体領域の互いの位置関係が、全体として線対称または点対称の位置関係となるように上記基板上に配置され、
上記複数の半導体素子が互いに電気的に接続されていることによって、上記基準半導体素子と同等の働きをすること
を特徴とする半導体素子。
すなわち、相対的に不純物濃度が高く、第1の極性を示す第1の半導体領域と、相対的に不純物濃度の低い半導体領域であるチャネル領域と、相対的に不純物濃度が高く、第1の極性とは逆極性を示す第2の半導体領域とが、互いに接して、かつ基板の面内方向に順列配置された第1のダイオードと、第1のダイオードの各半導体領域と実質的に等しいサイズの各半導体領域を備えた第2のダイオードとが、第1のダイオードのバイアス方向と、第2のダイオードのバイアス方向とを、互いに逆向きとするように、上記基板上に対称的に配置され、かつ、第1のダイオードと第2のダイオードとが電気的に並列接続され、第1のダイオードまたは第2のダイオードのチャネル幅を2倍にしたダイオードと同等の働きをすることを特徴とするダイオード。
Claims (14)
- 相対的に不純物濃度が高く、第1の極性を示す第1の半導体領域と、相対的に不純物濃度の低い半導体領域であるチャネル領域と、相対的に不純物濃度が高く、第1の極性とは逆極性を示す第2の半導体領域とが、互いに接しており、かつ基板の面内に含まれる特定方向に沿って順に配列されたダイオードを基準ダイオードとし、その基準ダイオードのチャネル幅をWとしたとき、
基準ダイオードのチャネル長に平行な上記特定方向の各半導体領域のサイズを変えずに、チャネル幅が上記チャネル幅Wより小さく、かつ互いに実質的に等しいチャネル幅W1を備えた2以上の偶数であるN個のダイオードを備え、
上記N個のダイオードをそれぞれ構成する各半導体領域の配列の方向が、全て上記特定方向に平行であり、かつ、上記各半導体領域の互いの位置関係が、全体として線対称または点対称の位置関係となるように上記基板上に配置され、
上記N個のダイオードが互いに電気的に接続されていることによって、上記基準ダイオードと同等の働きをすること
を特徴とするダイオード。 - 上記N個のダイオードの各チャネル領域のチャネル長は、ダイオード電流とダイオードに印加する電圧との関係を表すI-V特性がチャネル長の変化に対して、線形に変化するとみなせる範囲から選択されていること
を特徴とする請求の範囲第1項に記載のダイオード。 - 上記チャネル幅W1はW/Nであり、
N個のダイオードが互いに並列接続されていること
を特徴とする請求の範囲第1項または第2項に記載のダイオード。 - N/2個のダイオードを電気的に直列接続した第1の組と、N/2個のダイオードを電気的に直列接続した第2の組とを備え、
上記第1の組と第2の組とが、電気的に並列接続され、
上記チャネル幅W1はW/2であること
を特徴とする請求の範囲第1項または第2項に記載のダイオード。 - 上記Nが2の構成を含むダイオードであり、
当該2個のダイオードを第1のダイオードおよび第2のダイオードとするとき、第1のダイオードおよび第2のダイオードは、1つのSiアイランドの中に形成され、
かつ、上記第1の半導体領域または上記第2の半導体領域が、上記第1のダイオードおよび第2のダイオードによって、共有されていること
を特徴とする請求の範囲第1項または第2項に記載のダイオード。 - 上記Nが4の構成を含むダイオードであり、
当該4個のダイオードを、上記特定方向に沿って並んだ順に第1、第2、第3および第4のダイオードとし、かつ、上記第1の半導体領域が、上記第2のダイオードおよび第3のダイオードによって共有されている場合であって、
上記第2のダイオードと上記第4のダイオードとは構成的に等価であり、上記第4のダイオードは、上記特定方向に沿って、上記第3のダイオードに対し直列接続されて配置され、
上記第1のダイオードと上記第3のダイオードとは構成的に等価であり、上記第1のダイオードは、上記特定方向に沿って、上記第2のダイオードに対し直列接続されて配置され、
上記第1のダイオードおよび第2のダイオードは、上記第2の半導体領域を共有し、
上記第3のダイオードおよび第4のダイオードもまた、上記第2の半導体領域を共有し、
上記第1の半導体領域同士が相互に電気的に接続され、
上記第2の半導体領域同士もまた相互に電気的に接続されていること
を特徴とする請求の範囲第1項または第2項に記載のダイオード。 - 請求の範囲第1項から第6項のいずれか1項に記載のダイオードをフォトダイオードとして用いたこと
を特徴とする光センサ回路。 - (1)電源電圧を供給する電源供給線と、光センサ回路の光検出信号を出力する出力信号線との間に、ドレインソース導電路を形成するトランジスタと、
(2)上記光検出信号の読取期間中に、上記トランジスタのゲートの電位を容量を介して突き上げる行選択信号を供給する行選択信号線と、
(3)上記フォトダイオードのリセット期間中に、上記フォトダイオードに順方向バイアスをかける第1電圧と、光検出期間中に、上記フォトダイオードに逆バイアスをかける第2電圧とに変化するリセット信号を供給するリセット信号線とを備えたこと、
を特徴とする請求の範囲第7項に記載の光センサ回路。 - 上記フォトダイオードを構成する上記N個のフォトダイオードのそれぞれのカソードは、上記行選択信号線と上記ゲートとを上記容量を介して接続する導電路に接続される一方、それぞれのアノードが上記リセット信号線に接続されたこと、
を特徴とする請求の範囲第8項に記載の光センサ回路。 - 上記フォトダイオードは、N/2個のフォトダイオードを電気的に直列接続した第1の組と、N/2個のフォトダイオードを電気的に直列接続した第2の組とを備え、
上記第1の組および第2の組の各一端に位置するフォトダイオードのカソードは、それぞれ、上記行選択信号線と上記ゲートとを上記容量を介して接続する導電路に接続される一方、上記第1の組および第2の組の各他端に位置するフォトダイオードのアノードは、それぞれ、上記リセット信号線に接続されていること、
を特徴とする請求の範囲第8項に記載の光センサ回路。 - (1)電源電圧を供給する電源供給線と、光センサ回路の光検出信号を出力する出力信号線との間に、2つのドレインソース導電路を直列に形成するように、直列接続された第1のトランジスタおよび第2のトランジスタと、
(2)上記光検出信号の読取期間中に、上記第2のトランジスタのゲートに行選択信号を供給する行選択信号線と、
(3)上記フォトダイオードのリセット期間中に、上記フォトダイオードに順方向バイアスをかける第1電圧と、光検出期間中に、上記フォトダイオードに逆バイアスをかける第2電圧とに変化するリセット信号を供給するリセット信号線とを備え、
(4)上記フォトダイオードのカソードが、上記第1のトランジスタのゲートに接続されているとともに、容量を介して上記電源供給線に接続されていること、
を特徴とする請求の範囲第7項に記載の光センサ回路。 - 表示画面を構成する複数の画素の少なくとも1つに、請求の範囲第7項から第11項のいずれか1項に記載の光センサ回路を内蔵したこと
を特徴とする表示装置。 - 上記複数の画素のうち、隣接し合った所定数の複数の画素に対し、上記光センサ回路を1つずつ内蔵し、
当該光センサ回路の1つを構成する上記ダイオードおよびその他の素子を、上記所定数の複数の画素に分散して配置したこと
を特徴とする請求の範囲第12項に記載の表示装置。 - 上記複数の画素のそれぞれは、赤緑青三色の副画素によって構成され、
上記光センサ回路の1つを構成する上記N個のダイオードを、赤色の副画素と、青色の副画素とに分散して配置したこと、
を特徴とする請求の範囲第12項に記載の表示装置。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN200980103935XA CN101933165A (zh) | 2008-04-28 | 2009-01-14 | 二极管和包括该二极管的光传感器电路以及显示装置 |
US12/867,151 US8294079B2 (en) | 2008-04-28 | 2009-01-14 | Diode, photodetector circuit including same, and display device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008117434 | 2008-04-28 | ||
JP2008-117434 | 2008-04-28 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2009133716A1 true WO2009133716A1 (ja) | 2009-11-05 |
Family
ID=41254940
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2009/050371 WO2009133716A1 (ja) | 2008-04-28 | 2009-01-14 | ダイオードおよびそれを備えた光センサ回路並びに表示装置 |
Country Status (3)
Country | Link |
---|---|
US (1) | US8294079B2 (ja) |
CN (1) | CN101933165A (ja) |
WO (1) | WO2009133716A1 (ja) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009294315A (ja) * | 2008-06-03 | 2009-12-17 | Toshiba Mobile Display Co Ltd | 液晶表示装置 |
JPWO2011059038A1 (ja) * | 2009-11-13 | 2013-04-04 | シャープ株式会社 | 半導体装置およびその製造方法 |
JP2015029354A (ja) * | 2009-11-12 | 2015-02-12 | 株式会社半導体エネルギー研究所 | 半導体装置 |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2472854A4 (en) * | 2009-08-26 | 2013-12-04 | Sharp Kk | LIGHT DETECTOR AND DISPLAY DEVICE |
DE102013110695A1 (de) * | 2012-10-02 | 2014-04-03 | Samsung Electronics Co., Ltd. | Bildsensor, Verfahren zum Betreiben desselben und Bildverarbeitungssystem mit demselben |
EP3224700B1 (en) | 2014-11-24 | 2023-03-08 | Hewlett-Packard Development Company, L.P. | Touch screen |
CN104915657B (zh) | 2015-06-29 | 2018-09-18 | 京东方科技集团股份有限公司 | 基于ltps技术的掌纹识别电路、掌纹识别方法以及显示屏 |
CN108732609B (zh) * | 2017-04-24 | 2022-01-25 | 睿生光电股份有限公司 | 感测装置 |
CN107479760B (zh) * | 2017-09-22 | 2021-09-24 | 京东方科技集团股份有限公司 | 阵列基板及其制作方法、显示面板和显示系统 |
US10818816B2 (en) * | 2017-11-22 | 2020-10-27 | Advanced Semiconductor Engineering, Inc. | Optical device with decreased interference |
CN108303176B (zh) * | 2018-01-02 | 2020-02-11 | 京东方科技集团股份有限公司 | 一种光传感器、光检测方法和显示装置 |
DE102022124808A1 (de) | 2022-09-27 | 2024-03-28 | Infineon Technologies Ag | Leistungs-halbleitervorrichtung, messsystem und verfahren zum bestimmen eines stroms einer leistungs-halbleitervorrichtung |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006129427A1 (ja) * | 2005-05-31 | 2006-12-07 | Sharp Kabushiki Kaisha | 光センサ及び表示装置 |
WO2008044370A1 (fr) * | 2006-10-11 | 2008-04-17 | Sharp Kabushiki Kaisha | Affichage à cristaux liquides |
WO2008047677A1 (fr) * | 2006-10-19 | 2008-04-24 | Sharp Kabushiki Kaisha | Appareil d'affichage |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006267967A (ja) | 2005-03-25 | 2006-10-05 | Toshiba Matsushita Display Technology Co Ltd | 平面表示装置 |
GB2439118A (en) | 2006-06-12 | 2007-12-19 | Sharp Kk | Image sensor and display |
GB2439098A (en) | 2006-06-12 | 2007-12-19 | Sharp Kk | Image sensor and display |
JP5292787B2 (ja) * | 2007-11-30 | 2013-09-18 | ソニー株式会社 | 固体撮像装置及びカメラ |
JP5749975B2 (ja) * | 2010-05-28 | 2015-07-15 | 株式会社半導体エネルギー研究所 | 光検出装置、及び、タッチパネル |
-
2009
- 2009-01-14 US US12/867,151 patent/US8294079B2/en not_active Expired - Fee Related
- 2009-01-14 CN CN200980103935XA patent/CN101933165A/zh active Pending
- 2009-01-14 WO PCT/JP2009/050371 patent/WO2009133716A1/ja active Application Filing
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2006129427A1 (ja) * | 2005-05-31 | 2006-12-07 | Sharp Kabushiki Kaisha | 光センサ及び表示装置 |
WO2008044370A1 (fr) * | 2006-10-11 | 2008-04-17 | Sharp Kabushiki Kaisha | Affichage à cristaux liquides |
WO2008047677A1 (fr) * | 2006-10-19 | 2008-04-24 | Sharp Kabushiki Kaisha | Appareil d'affichage |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2009294315A (ja) * | 2008-06-03 | 2009-12-17 | Toshiba Mobile Display Co Ltd | 液晶表示装置 |
JP2015029354A (ja) * | 2009-11-12 | 2015-02-12 | 株式会社半導体エネルギー研究所 | 半導体装置 |
JPWO2011059038A1 (ja) * | 2009-11-13 | 2013-04-04 | シャープ株式会社 | 半導体装置およびその製造方法 |
Also Published As
Publication number | Publication date |
---|---|
CN101933165A (zh) | 2010-12-29 |
US20100308212A1 (en) | 2010-12-09 |
US8294079B2 (en) | 2012-10-23 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2009133716A1 (ja) | ダイオードおよびそれを備えた光センサ回路並びに表示装置 | |
US11574978B2 (en) | Display panel and display apparatus | |
WO2009139204A1 (ja) | 薄膜トランジスタおよびそれを備えた光センサ回路並びに表示装置 | |
KR101041970B1 (ko) | 액정 표시 장치 | |
CN102630313B (zh) | 显示装置 | |
US20110122111A1 (en) | Display device | |
CN112510015B (zh) | 显示面板以及电子设备 | |
US11251249B2 (en) | Display panel, display apparatus, display substrate, and method of fabricating display panel and display apparatus | |
CN114651332B (zh) | 显示基板和显示装置 | |
KR20210039323A (ko) | 이미지 센서의 반도체 구조, 칩 및 전자 장치 | |
US20120001880A1 (en) | Display device | |
JP2008282961A (ja) | 固体撮像装置 | |
WO2006129427A1 (ja) | 光センサ及び表示装置 | |
WO2011152307A1 (ja) | タッチセンサ付き表示装置 | |
JPWO2009041112A1 (ja) | 表示装置 | |
US11600681B2 (en) | Display device and manufacturing method thereof | |
CN115104186B (zh) | 显示基板、显示面板、显示装置 | |
US20220344425A1 (en) | Display panel and display apparatus | |
CN114464137B (zh) | 显示基板及显示装置 | |
KR20210050621A (ko) | 유기 발광 표시 장치 | |
US20130207190A1 (en) | Semiconductor device, and method for producing same | |
CN111261683A (zh) | 显示基板、显示面板和显示装置 | |
US20240138191A1 (en) | Display panel and display apparatus | |
US20240138192A1 (en) | Display panel and display apparatus | |
WO2021085484A1 (ja) | 光検出器 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 200980103935.X Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09738653 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12867151 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
NENP | Non-entry into the national phase |
Ref country code: JP |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 09738653 Country of ref document: EP Kind code of ref document: A1 |