Photoelectric converter

Claim 2

A photoelectric converter comprising a photosensor element, said photosensor element comprising: a transistor including a first semiconductor region having a first conductivity type, a first conductor, and an ohmic contact layer disposed between the first semiconductor region and the first conductor and comprising a semiconductor having the same conductivity type as and a higher impurity concentration than the first semiconductor region, a second semiconducor region disposed contiguous to the first semiconductor region, the second semiconductor region having the same conductivity type as and a lower impurity concentration than the first semiconductor region, a third semiconductor region disposed contiguous to the second semiconductor region and having a different conduct type from that of the second semiconductor region, an electric insulating region disposed contiguous to the third semiconductor region, and a second conductor connected to the electrically insulating region; the third semiconductor region, the electrically insulating region and the second conductor in combination being arranged to constitute a capacitor; and a fourth semiconductor region disposed contiguous to the third semiconductor region and having a different conductivity type from that of the third semiconductor region, and a third conductor; whereby said third semiconductor region is in a floating state so that the third semiconductor region stores a charge generated by photoexcitation by controlling the potential of the third semiconductor region through said electrically insulating region, an electric signal corresponding to the charge stored in the third semiconductor region is read out from the third conductor, and then the stored charge is refreshed through the third conductor.

Claim 3

The photoelectirc converter according to claim 1, wherein a fourth conductor different from said second conductor is connected to said electrically insulating region.

Claim 4

The photoelectric converter according to claim 1, wherein said second semiconductor region is at least partially surrounded by a fifth semiconductor region, said fifth semiconductor region having the same conductivity type as that of and a higher impurity concentration than that of the second semiconductor region.

Claim 5

The photoelectric converter according to claim 1, wherein a fifth semiconductor region having the same conductivity type as that of said third semiconductor region is buried in said first semiconductor region.

Claim 6

The photoelectric converter according to claim 1, wherein a fifth semiconductor region having the same conductivity type as that of said third semiconductor region is disposed laterally from the third semiconductor region through said second semiconductor region.

Claim 7

The photoelectric converter according to claim 1, wherein a diode is connected to said third semiconductor region through a fourth conductor.

Claim 8

The photoelectric converter according to claim 6, wherein said diode is a pn junction diode.

Claim 9

The photoelectric converter according to claim 1, wherein said photosensor element further comprises an insulated-gate type transistor having a drain region constituted by said fourth semiconductor region.

Claim 10

The photoelectric converter according to claim 1, wherein said photosensor element further comprises a MOS transistor having a source region constituted by said third semiconductor region.

Claim 11

The photoelectric converter according to claim 1, wherein said fourth semiconductor region has a thickness in the depth direction of from 0.2 to 0.3 micron or less.

Claim 12

The photoelectric converter according to claim 1, wherein said fourth semiconductor region has an impurity concentration of 1×1020 cm 3 or above.

Claim 13

The photoelectric converter according to claim 1, wherein said fourth semiconductor region has a distribution of impurity concentration decreasing from the side of the light incidence surface toward the opposite side.

Claim 14

The photoelectric converter according to claim 1, wherein said third semiconductor region has a distribution of impurity concentration decreasing from the side of the light incidence surface toward the opposite side.

Claim 15

The photoelectric converter according to claim 1, wherein said fourth semiconductor region is grounded when the charge is stored in said third semiconductor region.

Claim 16

The photoelectric converter according to claim 1, wherein said fourth semiconductor region is floated when the charge is stored in said third semiconductor region.

Claim 17

A photoelectric converter comprising a multiplicity of photosensor elements disposed in a matrix of rows and columns in a semiconductor body, each photosensor element comprising: a transistor including a first semiconductor region having a first conductivity type, a first conductor, and an ohmic contact layer disposed between the first semiconductor region and the first conductor and comprising a semiconductor having the same conductivity type as and a higher impurity concentration than the first semiconductor region, a second semiconductor region disposed contiguous to the first semiconductor region, the second semiconductor region having the same conductivity type as and a lower impurity concentration than the first semiconductor region, a third semiconductor region disposed contiguous to the second semiconductor region and having a different conductivity type from that of the second semiconductor region, an electrically insulating region disposed contiguous to the third semiconductor region, and a second conductor connected to the electrically insulating region; said third semiconductor region, said electrically insulating region and said second conductor in combination being arranged to constitute a capacitor; and a fourth semiconductor region disposed contiguous to the third semiconductor region and having a different conductivity type from that of the third semiconductor region, and a third conductor; said multiplicity of photosensor elements being isolated from each other with respect to their essential parts by element isolation regions, whereby said third semiconductor region is in a floating state so that the third semiconductor region stores a charge generated by photoexcitation by controlling the potential of the third semiconductor region through said electrically insulating region, an electric signal corresponding to the charge stored in the third semiconductor region is read out from the third conductor, and then the stored charge is refreshed through the third conductor.

Claim 18

A photoelectric converter comprising a multiplicity of photosensor elements disposed in a matrix of rows and columns in a semiconductor body, each photosensor element comprising: a transistor including a first semiconductor region having a first conductivity type, a first conductor, and an ohmic contact layer disposed between the first semiconductor region and the first conductor and comprising a semiconductor having the same conductivity type as and a higher impurity concentration than the first semiconductor region, a second semiconductor region disposed contiguous to the first semiconductor region, the second semiconductor region having the same conductivity type as and a lower impurity concentration than the first semiconductor region, a third semiconductor region disposed contiguous to the second semiconductor region and having a different conductivity type from that of the second semiconductor region, an electrically insulating region disposed contiguous to the third semiconductor region, and a second conductor connected to the electrically insulating region; said third semiconductor region, said electrically insulating region and said second conductor in combination being arranged to constitute a capacitor; and a fourth semiconductor region disposed contiguous to the third semiconductor region and having a different conductivity type from that of the third semiconductor region, and a third conductor; said multiplicity of photosensor elements being isolated from each other with respect to their essential parts by element isolation regions, whereby said third semiconductor region is in a floating state so that the third semiconductor region stores a charge generated by photoexcitation by controlling the potential of the third semiconductor region through said electrically insulating region, an electric signal corresponding to the charge stored in the third semiconductor region is read out from the third conductor, and then the stored charge is refreshed through the third conductor.

Claim 19

The photoelectric converter according to claim 16, wherein a fourth conductor different from said second conductor is connected to said electrically insulating region.

Claim 20

The photoelectric converter according to claim 16, wherein said second semiconductor region is at least partially surrounded by a fifth semiconductor region, said fifth semiconductor region having the same conductivity type as that of and a higher impurity concentration than that of the second semiconductor region.

Claim 21

The photoelectric converter according to claim 16, wherein a fifth semiconductor region having the same conductivity type as that of said third semiconductor region is buried in said first semiconductor region.

Claim 22

The photoelectric converter according to claim 16, wherein a fifth semiconductor region having the same conductivity type as that of said third semiconductor region is disposed laterally from the third semiconductor region through said second semiconductor region.

Claim 23

The photoelectric converter according to claim 16, wherein a diode is connected to said third semiconductor region through a fourth conductor

Claim 24

The photoelectric converter according to claim 21, wherein said diode is a pn junction diode.

Claim 25

The photoelectric converter according to claim 16, wherein said photosensor element further comprises an insulated-gate type transistor having a drain region constituted by said fourth semiconductor region.

Claim 26

The photoelectric converter according to claim 16, wherein said photosensor element further comprises a MOS transistor having a source region constituted by said third semiconductor region.

Claim 27

The photoelectric converter according to claim 16, wherein said fourth semiconductor region has a thickness in the depth direction of from 0.2 to 0.3 micron.

Claim 28

The photoelectric converter according to claim 16, wherein said fourth semiconductor region has an impurity concentration of 1×10 20 cm -3 or above.

Claim 29

The photoelectric converter according to claim 16, wherein said fourth semiconductor region has a distribution of impurity concentration decreasing from the side of the light incidence surface toward the opposite side.

Claim 30

The photoelectric converter according to claim 16, wherein said third semiconductor region has a distribution of impurity concentration decreasing from the side of the light incidence surface toward the opposite side.

Claim 31

The photoelectric converter according to claim 16, wherein said fourth semiconductor region is grounded when the charge is stored in said third semiconductor region.

Claim 32

The photoelectric converter according to claim 16, wherein said fourth semiconductor region is floated when the charge is stored in said third semiconductor region.

Claim 33

A photoelectric converter comprising a photosensor element which in turn comprises a first transistor and a second transistor, said first transistor including a first conductor, a first semiconductor region connected to the first conductor, a second semiconductor region, a high-resistivity third semiconductor region, and a fourth semiconductor region, and said second transistor including said said second semiconductor region, said high-resistivity third semiconductor region, said fourth semiconductor region, a fifth semiconductor region, and a second conductor connected to the fifth semiconductor region, said first semiconductor region and said fifth semiconductor region having conductivity types different from each other, said second semiconductor region having a different conductivity type from that of the first semiconductor region and being disposed contiguous to said first semiconductor region, said fourth semiconductor region having a different conductivity type from that of the fifth semiconductor region and being disposed contiguous to said fifth semiconductor region, said high resistivity third semiconductor region being disposed between said second and fourth semiconductor regions and electrically connecting said second and fourth semiconductor regions, one of said second and fourth semiconductor regions functioning to store holes of electron-hole pairs generated by photo-excitation and the other to store electrons.

Claim 34

A photoelectric converter comprising a photosensor element which in turn comprises a first transistor and a second transistor, said first transistor including a first conductor, a first semiconductor region connected to the first conductor, a second semiconductor region, a high-resistivity third semiconductor region, and a fourth semiconductor region, and said second transistor including said said second semiconductor region, said high-resistivity third semiconductor region, said fourth semiconductor region, a fifth semiconductor region, and a second conductor connected to the fifth semiconductor region, said first semiconductor region and said fifth semiconductor region having conductivity types different from each other, said second semiconductor region having a different conductivity type from that of the first semiconductor region and being disposed contiguous to said first semiconductor region, said fourth semiconductor region having a different conductivity type from that of the fifth semiconductor region and being disposed contiguous to said fifth semiconductor region, said high resistivity third semiconductor region being disposed between said second and fourth semiconductor regions and electrically connecting said second and fourth semiconductor regions, one of said second and fourth semiconductor regions functioning to store holes of electron-hole pairs generated by photo-excitation and the other to store electrons.

Claim 35

The photoelectric converter according to claim 31, wherein said first semiconductor region has the conductivity type of n+, and said fifth semiconductor region has the conductivity type of p + .

Claim 36

The photoelectric converter according to claim 31, wherein said second semiconductor region has the conductivity type of p.

Claim 37

The photoelectric converter according to claim 31, wherein said high-resistivity third semiconductor region is an n - region.

Claim 38

The photoelectric converter according to claim 31, said photosensor element further comprises an insulated-gate type transistor, said insulate-gate type transistor comprising: said second semiconductor region, a sixth semiconductor region having the same conductivity type as that of the second semiconductor region and disposed spaced apart from the second semiconductor region, a seventh semiconductor region disposed between the second and sixth semiconductor regions, having a different conductivity type from that of the second and sixth semiconductor regions and electrically connecting the second and sixth semiconductor regions, an electrically insulating region disposed on said seventh semiconductor region, and

Claim 39

a third conductor disposed above said seventh semiconductor region through said electric insulating region.

Claim 40

a third conductor disposed above said seventh semiconductor region through said electric insulating region.

Claim 41

The photoelectric converter according to claim 35, wherein said third conductor extends above said second semiconductor region along with said electrically insulating layer so that it has a function of controlling the potential of the second semiconductor region.

Claim 42

The photoelectric converter according to claim 36, wherein the portions of the third conductor and the electrically insulating region extending above the second semiconductor region constitute a MOS capacitor in combination with the second semiconductor region below the third electrode.

Claim 43

The photoelectric converter according to claim 35, wherein said electrically insulating region extends above said fourth semiconductor region and a fourth conductor is disposed on the extending portion of the electrically insulating region.

Claim 44

The photoelectric converter according to claim 38, wherein the fourth conductor, the portion of the electrically insulating region extending above the fourth semiconductor region and the fourth semiconductor region below the second electrode, in combination, form a MOS capacitor.

Claim 45

The photoelectric converter according to claim 35, wherein said second, sixth and seventh semiconductor regions are all disposed in said high-resistivity third semiconductor region.

Claim 46

The photoelectric converter according to claim 31, wherein said high-resistivity third semiconductor region is disposed in said fourth semiconductor region.

Claim 47

The photoelectric converter according to claim 31, wherein said first semiconductor region is disposed in said second semiconductor region.

Claim 48

The photoelectric converter according to claim 38, wherein said fourth conductor has a function of controlling the potential of said fourth semiconductor region.

Claim 49

The photoelectric converter according to claim 31, wherein said photosensor element further comprises an insulated-gate type transistor connected to said fourth semiconductor region.

Claim 50

The photoelectric converter according to claim 44, wherein said insulated-gate type transistor is an n-channel MOS transistor.

Claim 51

A photoelectric converter comprising a multiplicity of photosensor elements disposed in a matrix of rows and columns in a semiconductor body, each photosensor element comprising: a first transistor including a first conductor, a first semiconductor region connected to the first conductor, a second semiconductor region, a high-resistivity third semiconductor region, and a fourth semiconductor region, and a second transistor including said second semiconductor region, said high resistivity third semiconductor region, said fourth semiconductor region, a fifth semiconductor region, and a second conductor connected to the fifth semiconductor region, said first semiconductor region and said fifth semiconductor region having a conductivity types different from each other, said second semiconductor region having a different conductivity type from that of the first semiconductor region and being disposed contiguous to said first semiconductor region, said fourth semiconductor region having a different conductivity type from that of the fifth semiconductor region and being disposed contiguous to said fifth semiconductor region, said high-resistivity third semiconductor region being disposed between said second and fourth semiconductor regions and electrically connecting said second and fourth semiconductor regions, one of said second and fourth semiconductor regions functioning to store holes of electron-hole pairs generated by photo-excitation and the other to store electrons.

Claim 52

A photoelectric converter comprising a multiplicity of photosensor elements disposed in a matrix of rows and columns in a semiconductor body, each photosensor element comprising: a first transistor including a first conductor, a first semiconductor region connected to the first conductor, a second semiconductor region, a high-resistivity third semiconductor region, and a fourth semiconductor region, and a second transistor including said second semiconductor region, said high resistivity third semiconductor region, said fourth semiconductor region, a fifth semiconductor region, and a second conductor connected to the fifth semiconductor region, said first semiconductor region and said fifth semiconductor region having a conductivity types different from each other, said second semiconductor region having a different conductivity type from that of the first semiconductor region and being disposed contiguous to said first semiconductor region, said fourth semiconductor region having a different conductivity type from that of the fifth semiconductor region and being disposed contiguous to said fifth semiconductor region, said high-resistivity third semiconductor region being disposed between said second and fourth semiconductor regions and electrically connecting said second and fourth semiconductor regions, one of said second and fourth semiconductor regions functioning to store holes of electron-hole pairs generated by photo-excitation and the other to store electrons.

Claim 53

The photoelectric converter according to claim 46, wherein said first semiconductor region has the conductivity type of n + , and said fifth semiconductor region has the conductivity type of p + .

Claim 54

The photoelectric converter according to claim 46, wherein said second semiconductor region has the conductivity type of p.

Claim 55

The photoelectric converter according to claim 46, wherein said high-resistivity third semiconductor region is an n - region.

Claim 56

The photoelectric converter according to claim 46, wherein said photosensor element further comprises an insulated-gate type transistor, said insulated-gate type transistor comprising: said second semiconductor region, a sixth semiconductor region having the same conductivity type as that of the second semiconductor region and disposed spaced apart from the second semiconductor region, a seventh semiconductor region disposed between the second and sixth semiconductor regions, having a different conductivity type from that of the second and sixth semiconductor regions and electrically connecting the second and sixth semiconductor regions, an electrically insulating region disposed on said seventh semiconductor region, and a third conductor disposed above said seventh semiconductor region through said electrically insulating region.

Claim 57

The photoelectric converter according to claim 50, wherein said third conductor extends above said second semiconductor region along with said electrically insulating region so that it has a function of controlling the potential of the second semiconductor region.

Claim 58

The photoelectric converter according to claim 51, wherein the portions of the third conductor and the electrically insulating region extending above the second semiconductor region constitue a MOS capacitor in combination with the second semiconductor region below the third conductor.

Claim 59

The photoelectric converter according to claim 50, wherein said electrically insulating region extends above said fourth semiconductor region and a fourth conductor is disposed on the extending portion of the electrically insulating region.

Claim 60

The photoelectric converter according to claim 53, wherein the fourth conductor, the portion of the electrically insulating region extending above the fourth semiconductor region and the fourth semiconductor region below the second electrode, in combination, form a MOS capacitor.

Claim 61

The photoelectric converter according to claim 50, wherein said second, sixth and seventh semiconductor regions are all disposed in said high-resistivity third semiconductor region.

Claim 62

The photoelectric converter according to claim 46, wherein said high-resistivity third semiconductor region is disposed in said fourth semiconductor region.

Claim 63

The photoelectric converter according to claim 46, wherein said first semiconductor region is disposed in said second semiconductor region.

Claim 64

The photoelectric converter according to claim 53, wherein said fourth conductor has a function of controlling the potential of said fourth semiconductor region.

Claim 65

The photoelectric converter according to claim 46, wherein said photosensor element further comprises an insulated-gate type transistor connected to said fourth semiconductor region.

Claim 66

The photoelectric converter according to claim 59, wherein said insulated-gate type transistor is an n-channel MOS transistor.

Claim 67

A photoelectric converter comprising a photosensor element, said photosensor element comprising: a first transistor including a first and a second semiconductor region respectively having a first conductivity type, a first and a second conductor connected to the first and second semiconductor regions, respectively, and a third semiconductor region having a second conductivity type opposite to the first conductivity type and being in a floating state; a second transistor including a fourth semiconductor region having said second conductivity type and directly connected to said third semiconductor region, a fifth semiconductor region having said second conductivity type, a third conductor connected to the fifth semiconductor region, and a sixth semiconductor region having said first conductivity and being in a floating state; and a fourth conductor connected to said sixth semiconductor region through an electrically insulating layer so as to control the potential of the sixth semiconductor region.

Claim 68

A photoelectric converter comprising a photosensor element, said photosensor element comprising: a first transistor including a first and a second semiconductor region respectively having a first conductivity type, a first and a second conductor connected to the first and second semiconductor regions, respectively, and a third semiconductor region having a second conductivity type opposite to the first conductivity type and being in a floating state; a second transistor including a fourth semiconductor region having said second conductivity type and directly connected to said third semiconductor region, a fifth semiconductor region having said second conductivity type, a third conductor connected to the fifth semiconductor region, and a sixth semiconductor region having said first conductivity and being in a floating state; and a fourth conductor connected to said sixth semiconductor region through an electrically insulating layer so as to control the potential of the sixth semiconductor region.

Claim 69

The photoelectric converter according to claim 61, wherein a first high resistivity semiconductor region is interposed between said first and third semiconductor regions.

Claim 70

The photoelectric converter according to claim 61, wherein a second high resistivity semiconductor region is interposed between said fourth and sixth semiconductor regions.

Claim 71

The photoelectric converter according to claim 63, wherein said second high resistivity semiconductor region is a region where charge carriers are generated through photo-excitation.

Claim 72

The photoelectric converter according to claim 64, wherein, of the charge carriers photo-generated in said second high resistivity regions, one polarity of carriers are stored in said third semiconductor region and the other polarity of carriers are stored in said sixth semiconductor region.

Claim 73

The photoelectric converter according to claim 1, wherein said fourth semiconductor region has the same conductivity type as that of said first semiconductor region.

Claim 74

The photoelectric converter according to claim 16, wherein said fourth semiconductor region has the same conductivity type as that of said first semiconductor region.

Claim 75

The photoelectric converter according to claim 1, wherein said fourth semiconductor region has a surface area smaller than that of said first semiconductor region.

Claim 76

The photoelectric converter according to claim 16, wherein said fourth semiconductor region has a surface area smaller than that of said first semiconductor region.

Claim 77

The photoelectric converter according to claim 1, wherein said fourth semiconductor region is highly doped.

Claim 78

The photoelectric converter according to claim 16, wherein said fourth semiconductor region is highly doped.

Claim 79

The photoelectric converter according to claim 1, wherein said fourth semiconductor region is a high resistivity semiconductor region.

Claim 80

The photoelectric converter according to claim 16, wherein said fourth semiconductor region is a high resistivity semiconductor region.

Claim 81

A photoelectric conversion process comprising the steps of: (A) providing a photoelectric converter comprising: a transistor including a first semiconductor region having a first conductivity type, a first conductor, and an ohmic contact layer disposed between the first semiconductor region and the first conductor and comprising a semiconductor having the same conductivity type as and a higher impurity concentration than the first semiconductor region, a second semiconductor region disposed contiguous to the first semiconductor region, the second semiconductor region having the same conductivity type as and a lower impurity concentration than the first semiconductor region, a third semiconductor region disposed contiguous to the second semiconductor region and having a different conductivity type from that of the second semiconductor region, an electrically insulating region disposed contiguous to the third semiconductor region, and a second conductor connected to the electrically insulating region; said third semiconductor region, said electrically insulating region and said second conductor in combination being arranged to constitute a capacitor; and a fourth semiconductor region disposed contiguous to the third semiconductor region and having a different conductivity type from that of the third semiconductor region, and a third conductor; (B) sequentially and cyclically conducting the following stages of operations: (a) Charge Storage Operation, comprising setting the following initial conditions wherein: the first semiconductor region is held at a reverse polarity of voltage, the third semiconductor region is biased to a reverse polarity of voltage, and the fourth semiconductor region is grounded or floated and illuminating the photosensor element with incident light to store a charge corresponding to the incident light in the third semiconductor region, (b) Readout Operation, comprising holding the fourth semiconductor region in a floating state and forward biasing the third semiconductor region to output an electrical signal corresponding to the charge in the third semiconductor region; and (C) Refreshing Operation, comprising holding the first semiconductor region at a ground potential or a reverse polarity of voltage, holding the fourth semiconductor region at ground potential, and applying a forward polarity of voltage to the third semiconductor region to remove a charge remaining corresponding the photogenerated charge in the third semiconductor region.

Claim 82

A photoelectric conversion process comprising the steps of: (A) providing a photoelectric converter comprising: a transistor including a first semiconductor region having a first conductivity type, a first conductor, and an ohmic contact layer disposed between the first semiconductor region and the first conductor and comprising a semiconductor having the same conductivity type as and a higher impurity concentration than the first semiconductor region, a second semiconductor region disposed contiguous to the first semiconductor region, the second semiconductor region having the same conductivity type as and a lower impurity concentration than the first semiconductor region, a third semiconductor region disposed contiguous to the second semiconductor region and having a different conductivity type from that of the second semiconductor region, an electrically insulating region disposed contiguous to the third semiconductor region, and a second conductor connected to the electrically insulating region; said third semiconductor region, said electrically insulating region and said second conductor in combination being arranged to constitute a capacitor; and a fourth semiconductor region disposed contiguous to the third semiconductor region and having a different conductivity type from that of the third semiconductor region, and a third conductor; (B) sequentially and cyclically conducting the following stages of operations: (a) Charge Storage Operation, comprising setting the following initial conditions wherein: the first semiconductor region is held at a reverse polarity of voltage, the third semiconductor region is biased to a reverse polarity of voltage, and the fourth semiconductor region is grounded or floated and illuminating the photosensor element with incident light to store a charge corresponding to the incident light in the third semiconductor region, (b) Readout Operation, comprising holding the fourth semiconductor region in a floating state and forward biasing the third semiconductor region to output an electrical signal corresponding to the charge in the third semiconductor region; and (C) Refreshing Operation, comprising holding the first semiconductor region at a ground potential or a reverse polarity of voltage, holding the fourth semiconductor region at ground potential, and applying a forward polarity of voltage to the third semiconductor region to remove a charge remaining corresponding the photogenerated charge in the third semiconductor region.