Photoelectric conversion element and photoelectric conversion apparatus

• US 5,942,774 A
• Filed: 02/26/1996
• Issued: 08/24/1999
• Est. Priority Date: 02/24/1995
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Suzuki, Satoshi, Kamashita, Atsushi, Isogai, Tadao
• Primary Examiner(s): GUAY, JOHN FRANCIS
• Application Number:
  US08/606,995
• Time in Patent Office: 1,275 Days
• Field of Search: 257/292, 257/256, 257/257, 257/258, 257/272, 257/435, 257/443, 257/446, 257/445, 257/448, 257/461, 358/482
• US Class Current: 257/292
• CPC Class Codes: H01L 27/14603 Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
• CPC Class Codes: H01L 27/14643 Photodiode arrays; MOS imagers
• CPC Class Codes: H04N 25/616 involving a correlated sampling function, e.g. correlated double sampling [CDS] or triple sampling
• CPC Class Codes: H04N 25/65 applied to reset noise, e.g. KTC noise related to CMOS structures by techniques other than CDS
• CPC Class Codes: H04N 25/677 for reducing the column or line fixed pattern noise
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 25/77 Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components

Abstract

A photoelectric conversion element includes a photoelectric conversion portion for generating and storing a charge according to incident light, an amplifying portion having a control region for generating a signal output according to the charge received in the control region from the photoelectric conversion portion, a transfer control portion for transferring the charge generated and stored in the photoelectric conversion portion to the control region of the amplifying portion, a reset-purpose charge draining region for draining the charge transferred to the control region of the amplifying portion, and a reset-purpose control region for controlling the reset-purpose charge draining region. A reset operation can be performed without operating the amplifying portion. Also, a photoelectric conversion apparatus having high sensitivity and low dissipation power can be obtained.

Claims

1. A photoelectric conversion element comprising:

a photoelectric conversion portion for generating a charge according to incident light and storing the charge therein;

an amplifying portion having a control region for generating a signal output according to the charge received in the gate region from said photoelectric conversion portion;

a transfer control portion for transferring the charge generated and stored in said photoelectric conversion portion to the control region of said amplifying portion;

a reset control region for draining the charge transferred to the control region of said amplifying portion; and

a reset control electrode for controlling the electrical connection between said reset control region and the control region of said amplifying portion,

wherein said amplifying portion is comprised of a junction field effect transistor having a vertical semiconductor structure composed of a first conductivity type gate region, a second conductivity type channel region, and a first conductivity type semiconductot substrate, in order from the semiconductor surface toward the inside of the semiconductor substrate.

2. A photoelectric conversion element, comprising:

a photoelectric conversion portion for generating a charge according to incident light and storing the charge therein;

an amplifying portion having a control region for generating a signal output according to the charge received in the control region from said photoelectric conversion portion;

a transfer control portion for transferring the charge generated and stored in said photoelectric conversion portion to the control region of said amplifying portion;

a reset control region for draining the charge transferred to the control region of said amplifying portion; and

a reset control electrode for controlling the electrical connection between said reset control region and the control region of said amplifying portion,

wherein said amplifying portion is a junction field effect transistor having a vertical semiconductor structure composed of a first conductivity type shallow gate region, a second conductivity type shallow channel region, a first conductivity type gate region, a second conductivity type well region, and a first conductivity type semiconductor substrate in the order from the semiconductor surface toward the inside of the semiconductor substrate.

3. A photoelectric conversion element, comprising:

a photoelectric conversion portion for generating a charge according to incident light and storing the charge therein;

an amplifying portion having a control region for generating a signal output according to the charge received in the control region from said photoelectric conversion portion;

a transfer control portion for transferring the charge generated and stored in said photoelectric conversion portion to the control region of said amplifying portion;

a reset control region for draining the charge transferred to the control region of said amplifying portion; and

a reset control electrode for controlling the electrical connection between said reset control region and the control region of said amplifying portion,

wherein said amplifying portion is a junction field effect transistor having a vertical semiconductor structure composed of a first conductivity type shallow gate region, a second conductivity type shallow channel region, a first conductivity type gate region, a second conductivity type well region, and a first conductivity type semiconductor substrate in the order from the semiconductor surface toward the inside of the semiconductor substrate, and wherein said first conductivity type shallow gate region and said first conductivity type gate region are electrically connected with each other in a portion other than the channel forming portion.

4. A photoelectric conversion element, comprising:

a photoelectric conversion portion for generating a charge according to incident light and storing the charge therein;

an amplifying portion having a control region for generating a signal output according to the charge received in the control region from said photoelectric conversion portion;

a transfer control portion for transferring the charge generated and stored in said photoelectric conversion portion to the control region of said amplifying portion;

a reset control region for draining the charge transferred to the control region of said amplifying portion; and

a reset control electrode for controlling the electrical connection between said reset control region and the control region of said amplifying portion,

wherein said photoelectric conversion portion is a buried photodiode having a vertical overflow structure, wherein said amplifying portion is a junction field effect transistor having a vertical semiconductor structure composed of a first conductivity type shallow gate region, a second conductivity type shallow channel region, a first conductivity type gate region, a second conductivity type well region, and a first conductivity type semiconductor substrate in the order from the semiconductor surface toward the inside of the semiconductor substrate, wherein said first conductivity type shallow gate region and said first conductivity type gate region are electrically connected with each other in a portion other than the channel forming portion, and wherein an impurity concentration of said first conductivity type gate region is different from an impurity concentration of a charge storing portion of said buried photodiode.

5. The photoelectric conversion element according to claim 4, wherein the impurity concentration of said first conductivity type gate region is in the range of 6×

10¹⁵ cm^-3 to 3×

10¹⁶ cm^-3 and the impurity concentration of said charge storing portion of the buried photodiode is in the range of 5×

10¹⁵ cm^-3 to 3×

10¹⁶ cm^-3.

6. A photoelectric conversion apparatus comprising:

a plurality of photoelectric conversion elements arranged in a two-dimensional matrix, each said photoelectric conversion element comprising a photoelectric conversion portion for generating a charge according to incident light and storing the charge therein, an amplifying portion having a control region for generating a signal output according to the charge received in the control region from said photoelectric conversion portion, a transfer control portion for transferring the charge generated and stored in said photoelectric conversion portion to the control region of said amplifying portion, a reset control region for draining the charge transferred to the control region of said amplifying portion, and a reset control electrode for controlling the electrical connection between said reset control region and the control region of said amplifying portion;

a vertical scanning circuit; and

a pulse drive source;

wherein each of transfer control portions and reset control regions of said photoelectric conversion elements is respectively connected commonly along a horizontal scanning direction, thereby connecting to said vertical scanning circuit for pulse driving, and

wherein a reset control electrode of each of said photoelectric conversion elements is connected commonly to said pulse drive source.

7. A photoelectric conversion apparatus comprising:

a plurality of photoelectric conversion elements arranged in a two-dimensional matrix, each said photoelectric conversion element comprising a photoelectric conversion portion for generating a charge according to incident light and storing the charge therein, an amplifying portion having a control region for generating a signal output according to the charge received in the control region from said photoelectric conversion portion, a transfer control portion for transferring the charge generated and stored in said photoelectric conversion portion to the control region of said amplifying portion reset control region for draining the charge transferred to the control region of said amplifying portion, and a reset control electrode for controlling the electrical connection between said reset control region and the control region of said amplifying portion, and a control means for controlling the control region of said amplifying portion by capacitive coupling;

a vertical scanning circuit;

a pulse drive source; and

a power supply;

wherein each of transfer control portions and control means for controlling the control regions of said amplifying portions by capacitive coupling of said photoelectric conversion elements is respectively connected commonly along a horizontal scanning direction, thereby connecting to said vertical scanning circuit for pulse driving, and wherein a reset control electrode and a reset control region of each of said photoelectric conversion elements is respectively connected commonly, such that each of said reset control electrodes is connected to said pulse drive source and each of said reset control regions is connected to said power supply.

8. A photoelectric conversion apparatus comprising:

a plurality of photoelectric conversion elements arranged in a two-dimensional matrix, each said photoelectric conversion element comprising a photoelectric conversion portion for generating a charge according to incident light and storing the charge therein, an amplifying portion having a control region for generating a signal output according to the charge received in the control region from said photoelectric conversion portion, a transfer control portion for transferring the charge generated and stored in said photoelectric conversion portion to the control region of said amplifying portion, a reset control region for draining the charge transferred to the control region of said amplifying portion, a reset control electrode for controlling the electrical connection between said reset control region and the control region of said amplifying portion, and a control means for controlling the control region of said amplifying portion by capacitive coupling;

a vertical scanning circuit;

a pulse drive source; and

a power supply;

wherein a control means for controlling the control region of said amplifying portion by capacitive coupling and a reset control electrode of each of said photoelectric conversion elements is respectively connected commonly along a horizontal scanning direction, thereby connecting to said vertical scanning circuit for pulse driving, and

wherein each of transfer control portions and reset control regions of each of said photoelectric conversion elements is respectively connected commonly, such that each of said transfer control portions is connected to said pulse drive source and each of said reset control regions is connected to said power supply.

9. A photoelectric conversion apparatus comprising:

a plurality of photoelectric conversion elements arranged in a two-dimensional matrix, each said photoelectric conversion element comprising a photoelectric conversion portion for generating a charge according to incident light and storing the charge therein, an amplifying portion having a control region for generating a signal output according to the charge received in the control region from said photoelectric conversion portion, a transfer control portion for transferring the charge generated and stored in said photoelectric conversion portion to the control region of said amplifying portion, a reset control region for draining the charge transferred to the control region of said amplifying portion, and a reset control electrode for controlling the electrical connection between said reset control region and the control region of said amplifying portion;

a vertical scanning circuit for commonly driving said photoelectric conversion elements along a horizontal scanning direction;

first memory means for storing signal outputs for one horizontal line immediately after control regions of said amplifying portions are initialized according to vertical scanning; and

second memory means for storing signal outputs for one horizontal line immediately after said charges are transferred to the control regions of said amplifying portions according to vertical scanning.