Semiconductor range-finding element and solid-state imaging device

A semiconductor range-finding element comprising:

• a semiconductor layer of first conductivity type;
• a surface buried region of second conductivity type buried in a surface of the semiconductor layer;
• island-shaped first and second charge transfer-barrier regions of the first conductivity type buried in a part of a surface of the surface buried region;
• an island-shaped first charge read-out barrier region of the first conductivity type buried in a part of the surface of the surface buried region, separated by a part of the surface buried region from the first charge transfer-barrier region, configured to form a first potential well for accumulating signal charges transferred through the first charge transfer-barrier region between the first charge read-out barrier region and the first charge transfer-barrier region;
• an island-shaped second charge read-out barrier region of the first conductivity type buried in a part of the surface of the surface buried region, separated by a part of the surface buried region from the second charge transfer-barrier region, configured to form a second potential well for accumulating signal charges transferred through the second charge transfer-barrier region between the second charge read-out barrier region and the second charge transfer-barrier region;
• an insulating film covering the surface buried region, the first and second charge transfer-barrier regions, and the first and second charge read-out barrier regions;
• first and second transfer gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed in the first and second charge transfer-barrier regions, respectively, through the insulating film, so as to alternately transfer the signal charges to the first and second potential wells;
• and
• first and second read-out gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed in the first and second charge read-out barrier regions, respectively, through the insulating film,
• wherein, a light pulse reflected by a target sample enters as an optical signal in the surface buried region between the first and second charge transfer-barrier regions, and in the semiconductor layer just under the surface buried region, the optical signal is converted into the signal charges, and pulse signals are sequentially applied to the first and second transfer gate electrodes in synchronization with the light pulse so that a distance from the target sample is measured in accordance with a distribution ratio of the signal charges accumulated in the first and second potential wells.

A solid-state imaging device including a plurality of pixels arrayed in a one-dimensional direction, wherein each of the pixels comprises:

• a semiconductor layer of first conductivity type;
• an island-shaped buried charge-generation region of second conductivity type buried in a part of a surface of the semiconductor layer;
• island-shaped first and second buried charge-transfer regions of the second conductivity type buried in a part of the surface of the semiconductor layer, separated by a part of the semiconductor layer from the buried charge-generation region, configured to accumulate signal charges transferred from the buried charge-generation region;
• an island-shaped first buried charge read-out region of the second conductivity type buried in a part of the surface of the semiconductor layer, separated by a part of the semiconductor layer from the first buried charge-transfer region, to which the signal charges are transferred from the first buried charge-transfer region;
• an island-shaped second buried charge read-out region of the second conductivity type buried in a part of the surface of the semiconductor layer, separated by a part of the semiconductor layer from the second buried charge-transfer region, to which the signal charges are transferred from the second buried charge-transfer region;
• an insulating film covering the semiconductor layer, the buried charge-generation region, the first and second buried charge-transfer regions, and the first and second buried charge read-out regions;
• first and second transfer gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed between the buried charge-generation region and the first buried charge-transfer region and between the buried charge-generation region and the second buried charge-transfer region, respectively, through the insulating film, so as to alternately transfer the signal charges to the first and second buried charge-transfer regions;
• and
• first and second read-out gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed between the first buried charge-transfer region and the first buried charge read-out region and between the second buried charge-transfer region and the second buried charge read-out region, respectively, through the insulating film, so as to transfer the signal charges to the first and second buried charge read-out regions,
• wherein pulse signals are sequentially applied to the first and second transfer gate electrodes in all of the pixels arrayed in the one-dimensional direction, in synchronization with light pulse, a distance from the target sample is measured in accordance with a distribution ratio of the signal charges accumulated in the first and second buried charge-transfer regions in each of pixels.

A solid-state imaging device including a plurality of pixels arrayed in a one-dimensional direction, wherein each of the pixels comprises:

• a semiconductor layer of first conductivity type;
• a surface buried region of second conductivity type buried in a surface of the semiconductor layer;
• island-shaped first and second charge transfer-barrier regions of the first conductivity type buried in a part of a surface of the surface buried region;
• an island-shaped first charge read-out barrier region of the first conductivity type buried in a part of the surface of the surface buried region, separated by a part of the surface buried region from the first charge transfer-barrier region, configured to form a first potential well for accumulating signal charges transferred through the first charge transfer-barrier region between the first charge read-out barrier region and the first charge transfer-barrier region;
• an island-shaped second charge read-out barrier region of the first conductivity type buried in a part of the surface of the surface buried region, separated by a part of the surface buried region from the second charge transfer-barrier region, configured to form a second potential well for accumulating signal charges transferred through the second charge transfer-barrier region between the second charge read-out barrier region and the second charge transfer-barrier region;
• an insulating film covering the surface buried region, the first and second charge transfer-barrier regions, and the first and second charge read-out barrier regions;
• first and second transfer gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed in the first and second charge transfer-barrier regions, respectively, through the insulating film, so as to alternately transfer the signal charges to the first and second potential wells;
• and
• first and second read-out gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed in the first and second charge read-out barrier regions, respectively, through the insulating film,
• wherein, pulse signals are sequentially applied to the first and second transfer gate electrodes in synchronization with light pulse, and a distance from the target sample is measured in accordance with a distribution ratio of the signal charges accumulated in the first and second potential wells in each of the pixels arrayed in the one-dimensional direction.

A solid-state imaging device including a plurality of pixels arrayed in a two-dimensional matrix, wherein each of the pixels comprises:

• a semiconductor layer of first conductivity type;
• an island-shaped buried charge-generation region of second conductivity type buried in a part of a surface of the semiconductor layer;
• island-shaped first and second buried charge-transfer regions of the second conductivity type buried in a part of the surface of the semiconductor layer, separated by a part of the semiconductor layer from the buried charge-generation region, configured to accumulate signal charges transferred from the buried charge-generation region;
• an island-shaped first buried charge read-out region of the second conductivity type buried in a part of the surface of the semiconductor layer, separated by a part of the semiconductor layer from the first buried charge-transfer region, to which the signal charges are transferred from the first buried charge-transfer region;
• an island-shaped second buried charge read-out region of the second conductivity type buried in a part of the surface of the semiconductor layer, separated by a part of the semiconductor layer from the second buried charge-transfer region, to which the signal charges are transferred from the second buried charge-transfer region;
• an insulating film covering the semiconductor layer, the buried charge-generation region, the first and second buried charge-transfer regions, and the first and second buried charge read-out region;
• first and second transfer gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed between the buried charge-generation region and the first buried charge-transfer region and between the buried charge-generation region and the second buried charge-transfer region, through the insulating film, so as to alternately transfer the signal charges to the first and second buried charge-transfer regions;
• and
• first and second read-out gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed between the first buried charge-transfer region and the first buried charge read-out region and between the second buried charge-transfer region and the second buried charge read-out region, respectively, through the insulating film, so as to transfer the signal charges to the first and second buried charge read-out region,
• wherein pulse signals are sequentially applied to the first and second transfer gate electrodes, in synchronization with light pulse, and a distance from a target sample is measured in accordance with a distribution ratio of the signal charges accumulated in the first and second buried charge-transfer regions in each of the pixels arrayed in the two-dimensional matrix so that all of the pixels are two-dimensionally accessed, and a two-dimensional picture corresponding to the measured distance is consequently obtained.

A solid-state imaging device including a plurality of pixels arrayed in a two-dimensional matrix, wherein each of the pixels comprises:

• a semiconductor layer of first conductivity type;
• a surface buried region of second conductivity type buried in a surface of the semiconductor layer;
• island-shaped first and second charge transfer-barrier regions of the first conductivity type buried in a part of a surface of the surface buried region;
• an island-shaped first charge read-out barrier region of the first conductivity type buried in a part of the surface of the surface buried region, separated by a part of the surface buried region from the first charge transfer-barrier region, configured to form a first potential well for accumulating signal charges transferred through the first charge transfer-barrier region between the first charge read-out barrier region and the first charge transfer-barrier region;
• an island-shaped second charge read-out barrier region of the first conductivity type buried in a part of the surface of the surface buried region, separated by a part of the surface buried region from the second charge transfer-barrier region, configured to form a second potential well for accumulating signal charges transferred through the second charge transfer-barrier region between the second charge read-out barrier region and the second charge transfer-barrier region;
• an insulating film covering the surface buried region, the first and second charge transfer-barrier regions, and the first and second charge read-out barrier regions;
• first and second transfer gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed in the first and second charge transfer-barrier regions, respectively, through the insulating film, so as to alternately transfer the signal charges to the first and second potential wells;
• and
• first and second read-out gate electrodes arranged on the insulating film, configured to electro-statically control potentials of transfer channels formed in the first and second charge read-out barrier regions, respectively, through the insulating film,
• wherein pulse signals are sequentially applied to the first and second transfer gate electrodes, in synchronization with light pulse, and a distance from a target sample is measured in accordance with a distribution ratio of the signal charges accumulated in the first and second potential wells, in each of the pixels arrayed in the two-dimensional matrix, so that all of the pixels are two-dimensionally accessed, and a two-dimensional image corresponding to the measured distance is consequently obtained.