JP3246062B2 - Photo sensor system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo sensor system, and more particularly, to a photo sensor system capable of obtaining high sensitivity characteristics as a solid-state image sensor.

[0002]

2. Description of the Related Art Conventionally, a photo sensor system is usually
A plurality of photosensors are arranged in a matrix using a photodiode or a thin film transistor (TFT) as a light receiving element (photosensor). And
Each photosensor generates an electric charge according to the amount of irradiated light, and the luminance can be known by checking the amount of the electric charge. A scanning voltage is applied from the horizontal scanning circuit and the vertical scanning circuit to the photosensors arranged in a matrix, and the charge amount of each photosensor is detected. However, in a conventional photosensor, when a closed circuit is formed, generated charges are released as a current.
A selection transistor is formed for each photosensor separately from the photosensor and connected, and the selection transistor is driven by the horizontal scanning circuit and the vertical scanning circuit, thereby detecting the charge amount of each photosensor.

In particular, in a conventional photosensor system using a single crystal silicon substrate, the light receiving section and the scanning circuit are formed on the same plane of the substrate. ) And a CCD (Charge Coupled Dev) using a photodiode with a low signal current
ice) and the like, in order to achieve higher sensitivity, a multilayer structure in which an amorphous semiconductor is formed as a light receiving surface over the entire surface of a silicon substrate on which a scanning circuit is formed is being improved.

[0004]

However, in such a conventional photosensor system, since a selection transistor is formed for each photosensor and connected, each photosensor cell becomes large and the photosensor system becomes large. There is a problem that the pixel itself becomes large, which becomes an obstacle when pixels are densely mounted.

In the above-described photosensor system having a laminated structure, the light receiving portion is made of amorphous silicon (a).
-Si) Since it is formed of a photodiode, the signal current per unit area is small. For example, when the element size is on the order of 100 μm, the light current (current at the time of light irradiation) is 1 nA (nanoampere) to 10 pA (picoampere). ), And the difference from the dark current (current when no light is irradiated) is small, so that the sensitivity of the photosensor is reduced.

Accordingly, an object of the present invention is to provide a photosensor system which has a large difference between a bright current and a dark current, has high sensitivity light characteristics, and has a simplified manufacturing process. .

[0007]

A photosensor system according to the present invention generates a predetermined charge corresponding to the amount of irradiation light , and
Photoelectric conversion means having a gate electrode, a photoelectric conversion drive control means for driving and controlling the photoelectric conversion means, and a signal transport means for transporting an output signal of the photoelectric conversion means to the photoelectric conversion drive control means, At least a main part of the photoelectric conversion unit and at least a main part of the photoelectric conversion drive control unit are stacked and formed on a substrate made of single crystal silicon ,
Due to the high concentration impurity diffusion layer formed in single crystal silicon
Circuit element of the photoelectric conversion drive control means and the photoelectric conversion
The above object is achieved by forming the gate electrode of the switching means .

[0008] In this case, the photoelectric conversion means may include:
As described in, a source electrode and a drain electrode are disposed opposite to each other with a semiconductor layer made of amorphous silicon therebetween, and an insulating film is interposed on both sides of the semiconductor layer, the source electrode and the drain electrode with the insulating layer interposed therebetween. A first gate electrode and a second gate electrode opposed to the semiconductor layer are disposed, and one of the first gate electrode side and the second gate electrode side is a light irradiation side, and irradiation is performed from the light irradiation side. Alternatively, the photosensor may be a double-gate thin film transistor in which the light passes through the insulating film on the light irradiation side and irradiates the semiconductor layer.

According to a third aspect of the present invention, the first
Either the gate electrode side or the second gate electrode side
It is formed of a transparent conductive material, and the other is the single crystal silicon.
Formed by the high-concentration impurity diffusion layer formed during recon
Alternatively, the gate electrode may be a modified gate electrode .

[0010]

According to the photo sensor system of the first aspect, the light
At least a main part of the photoelectric conversion means and a photoelectric conversion drive control means.
At least the main part of the step is laminated on the substrate
Therefore, the photo sensor system itself can be downsized.
Pixel density and the light-receiving area aperture ratio
It is possible to increase the sensitivity and increase the sensitivity.

Further , a photosensor system according to claim 1 is provided.
High impurity concentration formed in the single crystal silicon substrate
Circuit element of photoelectric conversion drive control means is formed by object diffusion layer
This simplifies the film-forming process,
Various circuit elements can be configured with the same.

The photosensor system according to claim 1
In one embodiment, one of the gate electrodes of the photoelectric conversion means is
Due to the high concentration impurity diffusion layer formed in single crystal silicon
Simplifies the manufacturing process
be able to.

According to a second aspect of the present invention, there is provided a photo sensor system comprising:
As photoelectric conversion means, amorphous silicon or
A source electrode and a drain electrode are provided with a semiconductor layer
This semiconductor layer, the source electrode and the drain electrode
On both sides of the semiconductor layer via the insulating film.
Double gate with two gate electrodes provided at opposing positions
Uses a photosensor composed of thin-film transistors
As a result, the photoelectric conversion efficiency is increased, and high sensitivity optical characteristics are obtained.
Can be

[0014] In the photosensor system according to the third aspect,
Is either the first gate electrode side or the second gate electrode side
Light can be easily applied to the semiconductor layer from either side
Therefore, the photoelectric conversion efficiency can be increased, and the other is a single crystal
Formed by high concentration impurity diffusion layer formed in silicon
Has made it possible to further simplify the manufacturing process.
it can.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.

FIGS. 1 to 3 show a first embodiment of a photosensor system. FIG. 1 is a side sectional view showing the structure of the photosensor system, and FIG. FIG. 3 is a characteristic curve diagram showing output characteristics of the photosensor system when a voltage is applied.

In FIG. 1, a photo sensor system 1
Is a photosensor 2 of a photoelectric conversion unit that converts a light irradiation amount into a charge amount, a data line 3 that carries a signal from the photosensor 2, and a field effect that performs a switching action for reading a signal from the data line 3. Type n channel MO
S (Metal Oxide Semiconductor) transistor (n-M
OSFET) 4 and the like.

This photo sensor system 1
Here, a glass of a predetermined thickness or a CVD (Chemical Vapor Depositio) is formed on a p-type single crystal silicon substrate 5.
n) An insulating substrate 6 on which silicon oxide or silicon nitride is deposited by a method or the like is formed, the photosensor 2 is provided on the insulating substrate 6, and the single crystal silicon substrate 5 is An n-MOSFET 4 and the like are provided.

As shown in FIG. 1, the structure of the photosensor 2 is such that a bottom gate electrode 7 is formed on an insulating substrate 6 so as to cover the bottom gate electrode (BG) 7 and the insulating substrate 6. In addition, an insulating film 8 made of silicon nitride (SiN) is provided. Then, on the bottom gate electrode (BG) 7, at a position opposed to the bottom gate electrode (BG) 7 via the insulating film 8,
A semiconductor layer 9 is formed. This semiconductor layer 9 is formed of i-type amorphous silicon (ia-Si). A source electrode (S) 10 and a drain electrode (D) 11 made of an electrode material such as aluminum are formed on the semiconductor layer 9 at positions facing each other at a predetermined interval with the semiconductor layer 9 interposed therebetween. . These source electrodes (S)
The drain electrode (D) 11 is connected to the semiconductor layer 9 via ohmic contact layers 12 and 13 made of n ⁺ amorphous silicon in which a dopant such as phosphorus is diffused. Thus, a bottom transistor is formed.

The portion between the source electrode (S) 10 and the drain electrode (D) 11 and the portion between the ohmic contact layers 12 and 13 are made of the same insulating film 8 made of transparent silicon nitride. And a transparent conductive material (IT) on the semiconductor layer 9 at a position facing the bottom gate electrode (BG) 7 with an insulating film 8 interposed therebetween.
An O) top gate electrode (TG) 14 is formed.

The top gate electrode (TG) 14 is formed not only in the channel region of the semiconductor layer 9 for generating an electron-hole pair described later, but also on the upper surface of the ohmic contact layers 12 and 13 as shown in FIG. It is desirable to form it in a size that covers the same.

The top gate electrode (TG) 1
A transparent insulating film 8 (overcoat film) made of silicon nitride is formed on 4, and protects the photosensor 2.

In this embodiment, as shown in FIG. 1, the photo sensor 2 is irradiated with light from the top gate electrode (TG) 14 side in the direction of the arrow, and this irradiated light is irradiated with the top gate electrode (TG) 14 and When the semiconductor layer 9 is irradiated through the insulating film 8, electron-hole pairs corresponding to the amount of irradiation are induced in the semiconductor layer 9.

The thickness of each part of the photosensor 2 is, for example, 500 angstroms for the bottom gate electrode (BG) 7, 1500 angstroms for the semiconductor layer 9, 500 angstroms for the source electrode (S) and the drain electrode (D), and ohmic. The contact layers 12 and 13 are 250 Å, the insulating film 8 between the bottom gate electrode (BG) 7 and the semiconductor layer 9 is 2000 Å, and the insulating film 8 between the top gate electrode (TG) 14 and the semiconductor layer 9 is 2000 angstrom, the top gate electrode (TG) 14 is formed at 500 angstrom, and the insulating film (overcoat film) 8 covering the top gate electrode (TG) 14 is formed at 2000 angstrom.
In this embodiment, the gate length (L) between the source electrode (S) 10 and the drain electrode (D) 11 on the semiconductor layer 9 is 7 μm, and the gate width (W) in the depth direction is 10 μm.
It is formed at 0 μm.

As shown in FIG. 1, an n-MOSFET 4 which is a part of a circuit for controlling the drive of the photosensor 2 is formed on the single crystal silicon substrate 5. The output signal from the photo sensor 2 is read through the interface.

The n-MOSFET 4 has a single-crystal silicon substrate 5 in which a dopant such as phosphorus is diffused at a high concentration.
⁺ Source region (S) 15 and drain region (D) 16 are formed at predetermined intervals, and the source region (S) 1
A gate electrode 17 made of a conductive material is buried in the insulating substrate 6 with a predetermined thickness serving as a gate insulating film on a channel region between the drain region 5 and the drain region (D) 16. Then, a voltage exceeding the threshold voltage is applied to the gate electrode 17 to turn on the n-MOSFET 4, and a signal is read from the photosensor 2.

Although not shown in FIG. 1, on the single crystal silicon substrate 5, various circuit elements for driving and controlling the photosensor 2 described later are formed.

FIG. 2 is a functional block diagram of the photo sensor system shown in FIG. As shown in FIG. 2, the photosensor system 1 has a double gate (WG) amorphous silicon formed on an insulating substrate 6 using a T gate.
FT photo sensor 22 and its TFT photo sensor 22
And various circuit elements 23 formed on the single-crystal silicon substrate 5 for controlling the driving of the substrate.

The photoelectric conversion unit 24 of the TFT photo sensor 22
Is to extract the irradiation light amount as a charge amount. Since a TFT photosensor having a double gate structure using amorphous silicon for the semiconductor layer 9 is employed, the photoelectric conversion efficiency is increased, and high sensitivity optical characteristics can be obtained. Conventionally, C
A photodiode, such as a CD, having a transfer circuit for sequentially transferring charges on a semiconductor surface from one electrode to another electrode is used. However, as the photoelectric conversion means of this embodiment, a TFT photosensor or a phototransistor having a double gate structure is used, and the above transfer circuit becomes unnecessary and the S / N ratio is improved. It is possible to perform high-sensitivity light detection with little influence of the above.

Further, since the various circuit elements 23 for controlling the driving of the TFT photosensor 22 are formed on the single crystal silicon substrate 5, the various elements can be easily formed by using the impurity diffusion layer formed by the impurity diffusion step. It can be formed, and the manufacturing process can be simplified.

Various circuit elements 23 are connected to an external device to control a light detecting operation, a controller 25, an address decoder 26 for instructing an address at the time of horizontal scanning and vertical scanning of a photo sensor arranged in a matrix, A voltage level converter 27 for applying a predetermined voltage value to each electrode of the TFT photosensor having a double gate structure according to the light detection state of the converter 24, and a sense amplifier 28 for amplifying a signal read from the photoelectric converter 24. , A data transfer unit 26 for transferring the amplified signal, an output buffer 27 for outputting transfer data, and the like.

Next, the operation will be described.

As shown in FIG. 1, when a positive voltage, for example, +10 V is applied to the bottom gate electrode (BG) 7 of the photosensor 1, an n-channel is formed in the bottom transistor. Here, when a positive voltage of, for example, +5 V is applied between the source electrode (S) 10 and the drain electrode (D) 11, electrons are supplied from the source electrode (S) 10 side and a current flows. In this state, the top gate electrode (TG) 1
When a negative voltage, for example, −20 V, at which the channel due to the electric field of the bottom gate electrode (BG) 7 disappears, an electric field from the top gate electrode (TG) 14 is changed to an electric field from the bottom gate electrode (BG) 7. It works in a direction to reduce the influence on the channel layer, and as a result, the depletion layer extends in the thickness direction of the semiconductor layer 9 and pinches off the n-channel. At this time, when light is irradiated from the top gate electrode (TG) 14 side, the top gate electrode (T
G) An electron-hole pair is induced on the 14 side. However, since −20 V is applied to the top gate electrode (TG) 14, the induced holes are accumulated in the channel region and cancel the electric field of the top gate electrode (TG) 14. Therefore, an n-channel is formed in the channel region of the semiconductor layer 9, and a drain current _IDS flows between the source electrode (S) 10 and the drain electrode (D) 11. The drain current I _DS changes according to the amount of irradiation light.

As described above, the photosensor 2 controls the electric field from the top gate electrode (TG) 14 so as to act in a direction to prevent the electric field from the bottom gate electrode (BG) 7 from forming a channel. Since the n-channel is pinched off, the drain current (dark current) I _DS flowing when no light is irradiated becomes extremely small, for example, about 10 ⁻¹⁴ A. As a result, the photosensor 2 can sufficiently increase the difference between the drain current at the time of light irradiation (bright) and the drain current at the time of no light irradiation (dark), and the amplification factor of the bottom transistor at this time is:
Since the S / N ratio can be increased depending on the amount of light irradiated, a high-sensitivity photosensor can be obtained.

In the photosensor 2, when the top gate electrode (TG) 14 is set to, for example, 0 V while a positive voltage (+10 V) is applied to the bottom gate electrode (BG) 7, the semiconductor layer 9 and the top Holes can be discharged from trap levels of the insulating film 8 between the gate electrode (TG) 14 and refresh, that is, reset can be performed.
That is, when the photosensor 2 is used continuously, the insulating film 8 is used.
Trap level between the semiconductor layer 9 and the semiconductor layer 9 is filled with holes generated by light irradiation and holes injected from the drain electrode (D) 11, and the channel resistance in the non-light-irradiated state also decreases. In addition, the drain current increases when no light is irradiated. Therefore, 0 V is applied to the top gate electrode (TG) 14.
Is applied to cause the holes to be discharged, and reset.

Further, when a positive voltage is not applied to the bottom gate electrode (BG) 7,
A channel is not formed in the bottom transistor, and even when light irradiation is performed, a drain current does not flow and a non-selected state can be obtained. That is, the photosensor 2 can control the selected state and the non-selected state by controlling the voltage _VBG applied to the bottom gate electrode (BG) 7. When 0 V is applied to the top gate electrode (TG) 14 in this non-selected state, as described above,
The holes can be discharged from the trap levels of the insulating film 8 between the semiconductor layer 9 and the top gate electrode (TG) 14 to reset the holes.

Next, the above operation will be described with reference to FIG. 3 showing a drain current characteristic curve with respect to a voltage applied to each electrode of the photosensor 2. FIG. 3 is a graph showing the relationship between the bottom gate voltage V _BG applied to the bottom gate electrode (BG) 7 and the presence or absence of irradiation light as parameters.
G) Drain current characteristics when the top gate voltage V _TG applied to 14 is changed.

Therefore, as shown in FIG. 3, when the bottom gate voltage V _BG of the photosensor 2 is set to 0 V, the drain current characteristic curve when light is irradiated (during light) is T1, and when the light is not irradiated ( The dark current characteristic curve is T
2. That is, in this state, the top gate voltage V
_{Even if TG} changes from 0 V to −20 V, and regardless of the presence or absence of light irradiation, the drain current I _DS is 10 pA (picoamps) or less, and the photosensor 2 is in a non-selected state.

Further, even if the bottom gate voltage V _BG of the photosensor 2 is set to +10 V and the top gate voltage V _TG is changed from 0 V to −20 V in a state where light is irradiated, the drain current I _DS is shown in FIG. as in the B2 drain current characteristic curve of the bright time, always, 1 .mu.A or more drain current I _DS flows, light irradiation is detected. When the photosensor 2 is not irradiated with light, the top gate voltage V _TG is -14 as shown by B1 in the drain current characteristic curve at the time of darkness shown in FIG.
Below V, a drain current I _{DS of} 10 pA or less flows, and when the top gate voltage V _TG becomes higher than that, the drain current I _DS increases.

Therefore, as shown in FIG. 3, the photosensor 2 can control the sense state and the reset state by controlling the top gate voltage V _TG to, for example, 0 V and −20 V. Further, by controlling the bottom gate voltage V _BG to, for example, 0 V and +10 V, the selected state and the non-selected state can be controlled.
As a result, the top gate voltage V _TG and the bottom gate voltage V _TG
By controlling the _BG , the photo sensor 2 can operate as a photo sensor having both a function as a photo sensor and a function as a selection transistor.

As described above, in the photosensor system of the first embodiment, an insulating substrate having a predetermined thickness is provided on a single crystal silicon substrate, and an amorphous silicon having a double gate structure is provided on the insulating substrate. Since the TFT photosensor using is formed, the photoelectric conversion efficiency is increased, and high-sensitivity optical characteristics can be obtained. As a result, HDTV (HighDefi
nition Television) and the like. Also, since the signal current of the sensor section can be increased, the signal reading section can be configured by an XY-address method using MOS transistors, and can be used for high-speed reading by making full use of parallel-serial conversion. can do. Furthermore, this TF
Various circuits for driving and controlling the T photosensor are formed by using an impurity diffusion layer that selectively diffuses impurities into a single crystal silicon substrate, thereby reducing the number of film forming steps and making the device simple. Can be formed.
In addition, a structure in which the TFT photosensor is stacked on various circuits for driving and controlling the TFT photosensor is employed, so that the photosensor system can be miniaturized, the density of pixels can be increased, and the aperture ratio of the light receiving portion. And the sensitivity can be further increased.

[Second Embodiment] FIG. 4 is a side sectional view showing the structure of a photosensor system according to a second embodiment.

In FIG. 4, the photo sensor system 41
Is a photosensor 42 of a photoelectric conversion unit that converts a light irradiation amount into a charge amount, a data line 43 that carries a signal from the photosensor 42, and a field effect that performs a switching action for reading a signal from the data line 43. And an n-channel MOS (Metal Oxide Semiconductor) transistor (n-MOSFET) 44 or the like.

The photo sensor system 41
Is formed on a p-type single crystal silicon substrate 45 by forming an insulating substrate 46 on which glass of a predetermined thickness or silicon oxide or silicon nitride is deposited by a CVD (Chemical Vapor Deposition) method or the like. The photo sensor 42 is provided with the substrate 46 interposed therebetween, and the single crystal silicon substrate 45 is provided with the above-described n-MOSFET 44 and the like.

The characteristic structure of the photosensor 42 of the second embodiment is, as shown in FIG. 4, an n-type in which a dopant such as phosphorus is diffused in a p-type single crystal silicon substrate 45 at a high concentration.
That is, the bottom gate electrode 47 is formed by the high concentration diffusion layer of ⁺ . Then, a semiconductor layer 48 made of i-type amorphous silicon is formed directly above the bottom gate electrode 47 with the insulating substrate 46 interposed therebetween.

Then, a source electrode (S) 49 made of an electrode material such as aluminum is provided on the semiconductor layer 48 at a position opposed to the semiconductor layer 48 at a predetermined interval with the semiconductor layer 48 interposed therebetween.
And a drain electrode (D) 50 are formed. These source electrode (S) 49 and drain electrode (D) 50
Ohmic contact layers 51 each made of n ⁺ amorphous silicon in which a dopant such as phosphorus is diffused,
It is connected to the semiconductor layer 48 via 52. Thus, a bottom transistor is formed.

The portion between the source electrode (S) 49 and the drain electrode (D) 50 and the portion between the ohmic contact layers 51 and 52 are covered with an insulating film 53 made of transparent silicon nitride. And the semiconductor layer 4 described above.
8 is provided with a bottom gate electrode (BG) via an insulating film 53.
A top gate electrode (TG) 54 made of a transparent conductive material (ITO) is formed at a position facing 47.

Then, the top gate electrode (TG) 5
4, a transparent insulating film 53 (overcoat film) made of silicon nitride is formed.
Is protected.

In the second embodiment, as shown in FIG. 4, the photo sensor 42 has a top gate electrode (TG) 54
The light is irradiated in the direction of the arrow from the side, and the irradiated light passes through the top gate electrode (TG) 54 and the insulating film 53 and irradiates the semiconductor layer 48.
Hole pairs are induced in the semiconductor layer 48.

As shown in FIG. 4, an n-MOSFET 44, which is a part of a circuit for controlling the drive of the photosensor 42, is formed on the single crystal silicon substrate 45. Then, a voltage exceeding the threshold voltage is applied to the gate electrode 57 to turn on the n-MOSFET 44, and a signal is read from the photosensor 2.

The n-MOSFET 4 in the second embodiment
The characteristic configuration 4 is that an n ⁺ source region (S) 55 and a drain region (D) 56 in which a dopant such as phosphorus is diffused at a high concentration are formed at a predetermined interval in a single crystal silicon substrate 45. The insulating substrate 46 is used as a gate insulating film on a channel region between the source region (S) 55 and the drain region (D) 56, and a conductive film is formed on the insulating substrate 46 at an opposing position. A gate electrode 57 made of a material is formed.

Although not shown in FIG. 4, various circuit elements for driving and controlling the photosensor 42 are formed on the single crystal silicon substrate 45.

As described above, the photo sensor system 41 according to the second embodiment includes the photo sensor 42 and the n-MOSFET
44 is not stacked in the vertical position unlike the first embodiment, but one gate electrode of the double gate of the photosensor 42 is replaced with an n ⁺ high concentration impurity diffusion layer in the single crystal silicon substrate 45. Therefore, the film forming process can be simplified. A bottom gate electrode 47 formed of an n ⁺ high-concentration impurity diffusion layer formed in a p-type single crystal silicon substrate is element-isolated from other gate lines by a pn junction. 47 is 0V
And the selection operation is performed at +10 V, so that no current flows to the grounded p-type single-crystal silicon substrate side. Further, the insulating substrate 46 serves as a gate insulating film and a bottom gate insulating film of the n-MOSFET 44.
Is used, so that the manufacturing process can be further simplified.

The operation of the photosensor system 41 according to the second embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

[0055]

According to the photo sensor system having such a photo sensor, an insulating substrate having a predetermined thickness is provided on a single crystal silicon substrate, and a double gate is provided on the insulating substrate as a photoelectric conversion means. Since a TFT photosensor using amorphous silicon of (WG) structure was formed,
The photoelectric conversion efficiency is increased, and high sensitivity optical characteristics can be obtained.
Further, since the photoelectric conversion drive control means for controlling the drive of the photoelectric conversion means is formed on the single crystal silicon substrate, various circuit elements can be constituted by a simple manufacturing process using the impurity diffusion layer.

Further, since the photoelectric conversion means is formed on an insulating substrate, and the photoelectric conversion drive control means can be formed on a single crystal silicon substrate to have a laminated structure, the size of the photosensor system itself can be reduced. As a result, the density of the pixels can be increased, and the aperture ratio of the light receiving section can be increased, so that the sensitivity can be increased.

Further, one of the gate electrodes of the photoelectric conversion means is formed of a high concentration impurity diffusion layer in a single crystal silicon substrate, and the insulating substrate is used as an insulating film between the gate electrode and the semiconductor layer. As a result, the manufacturing process can be further simplified.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a configuration of a photosensor system according to a first embodiment.

FIG. 2 is a circuit block diagram of the photo sensor system of FIG.

FIG. 3 is a characteristic curve diagram showing output characteristics of the photo sensor in a state where a voltage is applied.

FIG. 4 is a side sectional view showing a configuration of a photosensor system according to a second embodiment.

[Explanation of symbols]

 1, 41 Photosensor system 2, 42 Photosensor 3, 43 Data line 4, 44 n-MOSFET 5, 45 Single crystal silicon substrate 6, 46 Insulating substrate 7, 47 Bottom gate electrode 8, 48 Insulating film 9, 49 Semiconductor Layer 10, 50 Source electrode 11, 51 Drain electrode 12, 13, 52, 53 Ohmic contact layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 31/02-31/0392 H01L 31/10-31/119 H01L 27/14-27/15

Claims (3)

(57) [Claims] 1. A predetermined charge is generated according to the amount of irradiation light.
A photoelectric conversion unit having a gate electrode; a photoelectric conversion drive control unit for driving and controlling the photoelectric conversion unit; and a signal transfer unit for transferring an output signal of the photoelectric conversion unit to the photoelectric conversion drive control unit. Whether at least a main part of the photoelectric conversion means and at least a main part of the photoelectric conversion drive control means are single-crystal silicon
Is layered on Ranaru substrate, form in the single crystal silicon
The photoelectric conversion driving control is performed by the formed high-concentration impurity diffusion layer.
A circuit element of the control means and the gate electrode of the photoelectric conversion means.
A photosensor system, wherein a pole is formed . 2. The photoelectric conversion means, wherein a source electrode and a drain electrode are arranged opposite to each other with a semiconductor layer made of amorphous silicon therebetween, and on both sides of the semiconductor layer, the source electrode and the drain electrode. A first layer opposed to the semiconductor layer via an insulating film;
A gate electrode and a second gate electrode are provided, and one of the first gate electrode side and the second gate electrode side is set as a light irradiation side, and light irradiated from the light irradiation side is insulated on the light irradiation side. 2. The photosensor system according to claim 1, wherein the photosensor is a photosensor comprising a thin film transistor having a double gate structure that irradiates the semiconductor layer through a film. 3. The first gate electrode side or the second gate.
One of the electrodes is made of a transparent conductive material.
And the other is a high-concentration impurity formed in the single-crystal silicon.
It is a gate electrode formed by a pure substance diffusion layer.
3. The photosensor system according to claim 2, wherein: