Granted Patent B2

US 12,628,447 · App. 17/463,627 · Granted May 12, 2026

Inventors: Olivier Saxod (Grenoble, FR); François Ayel (Grenoble, FR)

Assignee: Commissariat à l'Énergie Atomique et aux Énergies Alternatives

H10F39/80373G01S17/08G01S17/89

Abstract

Claims (20)

1 . Image sensor comprising a plurality of pixels formed inside and on top of a semiconductor substrate, each pixel comprising:

a photosensitive area formed in the semiconductor substrate;

a storage area formed in the semiconductor substrate; and

a first transistor of transfer between the photosensitive area and the storage area, wherein the first transfer transistor comprises a gate vertically extending in the semiconductor substrate, from a top surface of the semiconductor substrate, inside of a capacitive insulating trench, comprising an electrically-conductive region electrically insulated from the semiconductor substrate, delimiting the storage area, the gate of the first transfer transistor of each pixel being electrically insulated from the semiconductor substrate and from the conductive region;

wherein the capacitive insulating trench comprises, in top view, top and bottom horizontal portions, left-hand and right-hand vertical portions and an intermediate horizontal portion interposed between the top and bottom horizontal portions and extending from the right-hand vertical portion towards the left-hand vertical portion, the first transistor of transfer comprising a portion formed at an angle of the capacitive insulating trench where the left-hand vertical portion and the top horizontal portion intersect, and another portion formed at an end of the intermediate horizontal portion located opposite the left-hand vertical portion;

wherein the intermediate horizontal portion is parallel to the top horizontal portion and separated from the top horizontal portion by a distance in the range from 50 nm to 400 nm.

2 . Sensor according to claim 1 , wherein:

the conductive region is intended to be taken to a fixed potential; and

the gate is intended to be taken to a variable potential, having a first level controlling the setting to the on state of the first transfer transistor and a second level controlling the setting to the off state of the first transfer transistor.

3 . Sensor according to claim 1 , wherein the gate is made of a metal or of a metal alloy.

4 . Sensor according to claim 1 , wherein the gate is made of polysilicon.

5 . Sensor according to claim 1 , configured to estimate distances by time of flight.

6 . Sensor according to claim 1 , wherein the storage area is separated from the first transfer transistor by a second transfer transistor.

7 . Sensor according to claim 6 , wherein the second transfer transistor comprises a gate vertically extending in the semiconductor substrate, from the top surface of the semiconductor substrate, inside an insulating trench delimiting the storage area.

8 . Method of controlling a sensor according to claim 6 comprising, for each pixel, the steps of:

a) setting the second transfer transistor to the on state;

b) setting the first transfer transistor to the on state;

c) after steps a) and b), setting the first transfer transistor to the off state; and

d) after step c), setting the second transfer transistor to the off state.

9 . Method according to claim 8 , wherein steps a), and b) are carried out simultaneously.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (12)