Solid-state imaging apparatus and driving method thereof

• US 8,456,559 B2
• Filed: 04/03/2009
• Issued: 06/04/2013
• Est. Priority Date: 04/09/2008
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamashita, Yuichiro, Kobayashi, Masahiro
• Primary Examiner(s): VILLECCO, JOHN M
• Application Number:
  US12/918,685
• Publication Number:
  US 20100328302A1
• Time in Patent Office: 1,523 Days
• Field of Search: 348/308, 348/243, 348/246, 348/296, 348/302, 257/291, 257/290, 257/292, 257/222, 257/223, 257/225, 257/229, 257/230, 257/231, 257/233, 257/445, 257/446, 257/463
• US Class Current: 348/308
• CPC Class Codes: H01L 27/14609 Pixel-elements with integrated switching, control, storage or amplification elements scanning details of imagers (circuitry of solid-state image sensors H04N25/00); circuitry of imagers H04N25/70
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers

Abstract

A solid-state imaging apparatus includes the carrier holding portion and the amplifying portion in each pixel, wherein a first voltage supplied to a transfer electrode when the transfer portion for transferring carriers from the carrier holding portion to the amplifying portion is placed in a non-conducting state is opposite in polarity to a voltage supplied to the transfer electrode during the turning on period of the transfer portion, and a second voltage supplied to the control electrode of the carrier holding portion during a holding period in which the carriers are retained in the carrier holding portion is the same in polarity as the first voltage and is larger in absolute value than the first voltage.

Claims

1. A driving method of a solid-state imaging apparatus including a plurality of pixels, each comprising:

a photoelectric conversion portion;

a carrier holding portion including a semiconductor region capable of accumulating signal carriers generated in the photoelectric conversion unit, and a control electrode arranged above the semiconductor region sandwiching an insulating film between the semiconductor region and the control electrode, such that the carrier holding unit holds the signal carriers generated in the photoelectric conversion portion;

an amplifying portion; and

a transfer portion having a transfer electrode for controlling an electrical connection between an input portion of the amplifying portion and the carrier holding portion, wherein the driving method comprises steps of;

supplying the transfer electrode with a first voltage for turning off the electrical connection through the transfer portion, the first voltage being in a polarity opposite to a polarity of a voltage supplied to the transfer electrode during the turning on period of the transfer portion; and

supplying the control electrode with a second voltage during a period of holding the carrier by the carrier holding portion, the second voltage being in the same polarity as the first voltage and being larger than the first voltage.

2. The driving method of a solid-state imaging apparatus according to claim 1, further comprising

a reset portion for supplying a reference voltage to an input portion of the amplifying portion, such that a period of supplying the reference voltage to the input portion of the amplifying portion is at least partially overlapped with a period of supplying the second voltage to the transfer electrode at the turning off of the transfer portion.

3. A solid-state imaging apparatus including a plurality of pixels, each comprising:

a photoelectric conversion portion having a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type for forming PN junction with the first semiconductor region, for generating a par of a signal carrier and a carrier of a polarity opposite to that of the signal carrier according to an incident light;

a carrier holding portion including a third semiconductor region of the first conductivity type, and a control electrode arranged over the third semiconductor region sandwiching an insulating film between the control electrode arranged and the third semiconductor region for controlling a potential state as to the signal carrier in a region in the vicinity of an interface to the insulating film;

a fourth semiconductor region of the first conductivity type;

a first transfer portion having a first transfer electrode arranged over a first path between the third and fourth semiconductor regions sandwiching an insulating film between the first transfer electrode and the first path, and being capable of controlling a potential state as to the signal charge on the first path; and

a reset portion for setting the fourth semiconductor region at a reference potential, wherein

a voltage supply portion for supplying a voltage to the first transfer portion and to the control electrode is provided,

the voltage supply portion supplies, during a period of non-conducting of the first transfer portion, to the first transfer electrode a first voltage of a polarity opposite to that of a voltage supplied during a period of turning on the first transfer portion, and

the voltage supply portion supplies, during a period of an accumulation period of the charge holding portion, to the control electrode a second voltage of the same polarity as the first voltage and larger than the first voltage.

4. The solid-state imaging apparatus according to claim 3, further comprising

a second transfer electrode arranged over a second path between the photoelectric conversion portion and the carrier holding portion sandwiching an insulating film between the second transfer electrode and the second path.

5. The solid-state imaging apparatus according to claim 4, wherein

the second path between the photoelectric conversion portion and the carrier holding portion is a buried channel.

6. The solid-state imaging apparatus according to claim 4, further comprising

a carrier discharging portion comprising a fifth semiconductor region of the first conductivity type, and a carrier discharging electrode arranged over a third path between the photoelectric conversion portion and the fifth semiconductor region sandwiching an insulating film between the carrier discharging electrode and the third path, and

a potential as to the signal carrier on the second path is lower than a potential as to the signal carrier on the third path.

7. The solid-state imaging apparatus according to claim 5, further comprising

the control electrode extends to the second path.

8. A solid-state imaging apparatus including a plurality of pixels, each comprising:

a photoelectric conversion portion having a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type for forming PN junction with the first semiconductor region, for generating a par of a signal carrier and a carrier of a polarity opposite to that of the signal carrier according to an incident light;

a carrier holding portion including a third semiconductor region of the first conductivity type, and a control electrode arranged over the third semiconductor region sandwiching an insulating film between the control electrode arranged and the third semiconductor region for controlling a potential state as to the signal carrier in a region in the vicinity of an interface to the insulating film;

a fourth semiconductor region of the first conductivity type;

a first transfer portion having a first transfer electrode arranged over a first path between the third and fourth semiconductor regions sandwiching an insulating film between the first transfer electrode and the first path, and being capable of controlling a potential state as to the signal charge on the first path; and

a reset portion for setting the fourth semiconductor region at a reference potential, wherein

a second transfer electrode is arranged over a second path between the photoelectric conversion portion and the carrier holding portion sandwiching an insulating film between the second transfer electrode and the second path,

a carrier discharging portion is provides and comprises a fifth semiconductor region of the first conductivity type, and a carrier discharging electrode arranged over a third path between the photoelectric conversion portion and the fifth semiconductor region sandwiching an insulating film between the carrier discharging electrode and the third path,

a voltage supply portion for supplying a voltage to the first transfer portion and to the control electrode is provided,

the voltage supply portion supplies, during a period of non-conducting of the first transfer portion, to the first transfer electrode a first voltage of a polarity opposite to that of a voltage supplied during a period of turning on the first transfer portion,

the voltage supply portion supplies, during a period of an accumulation period of the charge holding portion, to the control electrode a second voltage of the same polarity as the first voltage and larger than the first voltage,

the second path between the photoelectric conversion portion and the carrier holding portion is a buried channel, and

a potential as to the signal carrier on the second path is lower than a potential as to the signal carrier on the third path.