Semiconductor photoelectric converter

Claim 2

A solid-state photoelectric converter having a principal surface and including a semiconductor substrate of a first conductivity type in juxtaposition with said principal surface and a unit photosensitive semiconductor region of said first conductivity type contiguous to said principal surface for converting a quantity of light projected onto said principal surface to an elementary electrical signal related to said quantity, wherein the improvement comprises an interposed semiconductor region of a second conductivity type opposite to said first conductivity type contiguous to said photosensitive semiconductor region and forming an elementary junction with said substrate and biassing means for reversedly biassing said junction to substantially completely deplete said interposed semiconductor region.

Claim 3

A solid-state photoelectric converter as claimed in Claim 1, wherein said interposed semiconductor region is given a predetermined impurity concentration and a predetermined thickness between said photosensitive semiconductor region and said substrate, said biassing means being for supplying a predetermined reverse bias voltage across said junction with said voltage selected in consideration of said impurity concentration and said thickness.

Claim 4

A solid-state photoelectric converter as claimed in Claim 2, wherein said impurity concentration and said thickness are selected between 10 14 and 10 16 atoms per cubic centimeter and 0.5 and 20 microns, respectively.

Claim 5

A solid-state photoelectric converter as claimed in Claim 1, 2, or 3, further comprising a covering semiconductor region of said first conductivity type covering said phtosensitive semiconductor region with a portion of said principal surface interposed.

Claim 6

A solid-state photoelectric converter as claimed in Claim 1, 2, or 3, further comprising a covering semiconductor region of said first conductivity type covering said photosensitive remiconductor region, said covering semiconductor region having an impurity concentration and a thickness selected between 10 15 and 10 20 atoms per cubic centimeter and between 0. 1 and 5 microns, respectively.

Claim 7

A solid-state photoelectric converter comprising a semiconductor substrate of first conductivity type, a first semiconductor layer of a second conductivity type opposite to said first conductivity type, said first semiconductor layer being formed on said semiconductor substrate to form a PN-junction therebetween a second semiconductor layer of said first conductivity type formed on said first semiconductor layer, said second semiconductor layer accumulating carriers generated in response to incident light therein, biasing means for reverse-biasing said PN-junction so as to deplete said first semiconductor layer, and means for deriving said charges accumulated in said second semiconductor layer as an electrical signal.

Claim 8

A solid-state photoelectric converter comprising a semiconductor substrate of first conductivity type, a first semiconductor layer of a second conductivity type opposite to said first conductivity type, said first semiconductor layer being formed on said semiconductor substrate to form a PN-junction therebetween a second semiconductor layer of said first conductivity type formed on said first semiconductor layer, said second semiconductor layer accumulating carriers generated in response to incident light therein, biasing means for reverse-biasing said PN-junction so as to deplete said first semiconductor layer, and means for deriving said charges accumulated in said second semiconductor layer as an electrical signal.

Claim 9

A solid-state photoelectric converter as claimed in Claim 6, wherein said first semiconductor layer has an impurity concentration between 10 14 and 10 16 atoms per cubic centimeter and a thickness between 0. 5 and 20 microns.

Claim 10

A solid-state photoelectric converter as claimed in Claim 6 or 7, further comprising a third semiconductor layer of said second conductivity type, said third semiconductor layer being disposed on said second semiconductor layer, and a junction between said second and third semiconductor layers being reversedly biased. -

Claim 11

A solid- state photoelectric converter as claimed in Claim 6 or 7, further comprising a third semiconductor layer of said second conductivity type formed on said second semiconductor layer and connected to said first semiconductor layer, said third semiconductor layer having an impurity concentration between 10 15 and 10 20 atoms per cubic centimeter and a thickness between 0. 1 and 5 microns.

Claim 12

A solid-state photoelectric converter comprising: a semiconductor substrate of first conductivity type; an interposed semiconductor region of second conductivity type opposite to said first conductivity type formed on said semiconductor substrate, said interposed semiconductor region having a first portion forming a first PN-junction with said semiconductor substrate and a second portion forming a second PN-junction with said semiconductor substrate; a plurality of photo-sensitive semiconductor regions of said first conductivity type formed in said first portion of said interposed semiconductor region, said photo-sensitive semiconductor regions being arranged in a line, and each of said photo-sensitive semiconductor regions accumulating charges therein in response to incident light; means for deriving charges accumulated in said photo-sensitive semiconductor regions as an electrical signal; and biasing means for reversely biasing said first and second PN-junctions so as to completely deplete said first portion of said interposed semiconductor region up to said photo- sensitive semiconductor regions and so as to partly deplete said second portion of said interposed semiconductor region.

Claim 13

A solid-state photoelectric converter comprising: a semiconductor substrate of first conductivity type; an interposed semiconductor region of second conductivity type opposite to said first conductivity type formed on said semiconductor substrate, said interposed semiconductor region having a first portion forming a first PN-junction with said semiconductor substrate and a second portion forming a second PN-junction with said semiconductor substrate; a plurality of photo-sensitive semiconductor regions of said first conductivity type formed in said first portion of said interposed semiconductor region, said photo-sensitive semiconductor regions being arranged in a line, and each of said photo-sensitive semiconductor regions accumulating charges therein in response to incident light; means for deriving charges accumulated in said photo-sensitive semiconductor regions as an electrical signal; and biasing means for reversely biasing said first and second PN-junctions so as to completely deplete said first portion of said interposed semiconductor region up to said photo- sensitive semiconductor regions and so as to partly deplete said second portion of said interposed semiconductor region.

Claim 14

A solid-state photoelectric converter as claimed in Claim 10, wherein said deriving means includes a region of said first conductivity type formed in said second portion to transfer the charges therealong.

Claim 15

A solid-state photoelectric converter as claimed in Claim 10, wherein said first and second portion have the same impurity concentration, and said first portion has a thickness thinner than that of second portion.

Claim 16

A solid-state photoelectric converter as claimed in Claim 12, wherein said impurity concentration of said first and second portion is between 10 14 and 10 16 atoms per cubic centimeter, the thickness of said first portion is between 0.5 and 20 microns, and the thickness of said second portion is between 1 and 100 microns.

Claim 17

A solid-state photoelectric converter as claimed in Claim 10, 11, 12 or 13, further comprising at least one covering semiconductor region of said second conductivity type covering said photo-sensitive semiconductor regions.

Claim 18

A solid-state photoelectric converter as claimed in Claim 10, 11, 12 or 13, further comprising at least one covering semiconductor region of said second conductivity type formed on said photo-sensitive semiconductor regions, said covering semiconductor region being connected to said interposed semiconductor region and having an impurity concentration between 10 15 and 10 20 atoms per cubic centimeter and a thickness between 0. 1 and 5 microns.

Claim 19

A solid-state photoelectric converter comprising: a semiconductor substrate of first conductivity type; a plurality of interposed semiconductor regions of second conductivity type opposite to said first conductivity type formed on said semiconductor substrate, each of said interposed semiconductor regions having a first portion forming a first PN-junction with said semiconductor substrate and a second portion forming a second PN-junction with said semiconductor substrate, and said interposed semiconductor regions being arranged in parallel with each other; a plurality of photo-sensitive semiconductor regions of said first conductivity type formed in said first portions of said interposed semiconductor regions, said photo-sensitive semiconductor regions being arranged in rows and columns, each of said row being formed in the same first portion, and each of said photo-sensitive semiconductor regions accumulating charges therein in response to incident light; vertical charge transfer regions formed in said second portions of said interposed semiconductor regions; means for transferring charges accumulated in said photo- sensitive semiconductor regions to said vertical charge transfer regions; means for converting a quantity of charges transferred along said vertical charge transfer regions to an electrical signal; and means for reversely biasing said first and second PN-junctions so as to deplete completely said first portions and not completely said second portions.

Claim 20

A solid-state photoelectric converter comprising: a semiconductor substrate of first conductivity type; a plurality of interposed semiconductor regions of second conductivity type opposite to said first conductivity type formed on said semiconductor substrate, each of said interposed semiconductor regions having a first portion forming a first PN-junction with said semiconductor substrate and a second portion forming a second PN-junction with said semiconductor substrate, and said interposed semiconductor regions being arranged in parallel with each other; a plurality of photo-sensitive semiconductor regions of said first conductivity type formed in said first portions of said interposed semiconductor regions, said photo-sensitive semiconductor regions being arranged in rows and columns, each of said row being formed in the same first portion, and each of said photo-sensitive semiconductor regions accumulating charges therein in response to incident light; vertical charge transfer regions formed in said second portions of said interposed semiconductor regions; means for transferring charges accumulated in said photo- sensitive semiconductor regions to said vertical charge transfer regions; means for converting a quantity of charges transferred along said vertical charge transfer regions to an electrical signal; and means for reversely biasing said first and second PN-junctions so as to deplete completely said first portions and not completely said second portions.

Claim 21

A solid-state photoelectric converter as claimed in Claim 16, wherein said vertical charge transfer regions are said first conductivity type and form charge- coupled devices together with transfer electrodes formed above said vertical charge transfer regions.

Claim 22

A solid-state photoelectric converter as claimed in Clain 16, wherein said first and second portions of said interposed semiconductor regions have the same impurity concentrations, and said first portions are thinner than said second portions.

Claim 23

A solid-state photoelectric converter as claimed in Claim 18, wherein said impurity concentrations are between 10 14 and 10 16 atoms per cubic centimeter, the thickness of said first portions is between 0.5 and 20 microns, and the thickness of said second portions is between 1 and 100 microns.

Claim 24

A solid- state photoelectric converter as claimed in Clain 16, 17, 18 or 19, further comprising covering semiconductor regions of said second conductivity type covering said photo-sensitive semiconductor regions.

Claim 25

A solid-state photoelectric converter as claimed in Claim 16, 17, 18 or 19, further comprising covering semiconductor regions of said second conductivity type formed on said photo-sensitive semiconductor regions, said covering semiconductor regions being connected to said interposed semiconductor regions and having an impurity concentration betwen 10 15 and 10 20 atoms per cubic centimeter and a thick between 0. 1 and 5 microns.