CN-122002918-A - Electronic equipment

Abstract

Embodiments of the present disclosure relate to electronic devices. An electronic device includes a single photon avalanche diode including a PN junction having a first dimension less than 1.2 μm, the single photon avalanche diode being surrounded by an insulating wall, the first dimension being a minimum dimension of the junction.

Inventors

• R - A - Bianchi
• S. Pres
• C. M-N. Bier
• D. Gransky
• NICHOLSON IAN

Assignees

• 意法半导体国际公司

Dates

Publication Date

20260508

Application Date

20251031

Priority Date

20241108

Claims (20)

1. 1. An electronic device, comprising: A substrate; A single photon avalanche diode, the single photon avalanche diode has a PN junction comprising: An anode having a first portion; a cathode opposite the first portion of the anode in a first direction; A portion of the substrate between the first portion of the anode and the cathode, and A first dimension of the first portion of the anode along a second direction perpendicular to the first direction, the first dimension being less than 1.2 μm and being a minimum dimension of the junction, and An insulating wall surrounding the single photon avalanche diode.
2. 2. The apparatus of claim 1, wherein the first dimension is less than 1 μιη.
3. 3. The apparatus of claim 1, wherein the insulating wall has a conductive core and an insulating sheath.
4. 4. The apparatus of claim 1, wherein the cathode of the single photon avalanche diode comprises an N doped region in the substrate, and wherein the anode of the single photon avalanche diode comprises: the first portion aligned with the cathode, and A second portion surrounding a region of the substrate, the region of the substrate being separated from the cathode by the first portion.
5. 5. The apparatus of claim 1, wherein the first dimension is between 0.7 μιη and 1.2 μιη.
6. 6. The apparatus of claim 3, wherein a second dimension is less than 0.5 μιη, the second dimension being a smallest dimension of overlap between the first portion and the second portion of the anode.
7. 7. A method of manufacture, comprising: forming a single photon avalanche diode having a PN junction comprising: An anode having a first portion; a cathode opposite the first portion of the anode in a first direction; A portion of the substrate between the first portion of the anode and the cathode, and A first dimension of the first portion of the anode along a second direction perpendicular to the first direction, the first dimension being less than 1.2 μm and being a minimum dimension of the junction, wherein forming comprises doping at least a portion of the anode of the single photon avalanche diode, and An insulating wall is formed that encloses the single photon avalanche diode.
8. 8. The method of claim 7, wherein the first dimension is less than 150% of the lateral spatial resolution of the doping method used to form at least part of the anode of the single photon avalanche diode.
9. 9. The method of claim 7, wherein the doping method used is ion implantation of a doping element.
10. 10. The method of claim 7, wherein the first dimension is greater than 90% of the lateral spatial resolution of the doping method.
11. 11. The method of claim 7, wherein the lateral spatial resolution of a doping method is a minimum value of a minimum dimension of the upper surface of a region that allows an upper surface of the region to be planar when doping the region having a rectangular parallelepiped shape.
12. 12. The method of claim 7, wherein the first dimension is between 0.7 μιη and 1.2 μιη.
13. 13. The method of claim 8, wherein forming the single photon avalanche diode comprises forming a hard mask comprising openings having at least one of dimensions less than 150% of the lateral spatial resolution of the doping method.
14. 14. The method of claim 8, wherein the doping is from a face closest to the cathode.
15. 15. The method of claim 8, wherein the first dimension is less than 130% of the lateral spatial resolution of the doping method used to form at least part of the anode of the single photon avalanche diode.
16. 16. An apparatus, comprising: a substrate having a first surface opposite a second surface; A first doped region buried in the substrate; A second doped region buried in the substrate and opposite to the first doped region in a first direction; A third doped region on the first undoped region of the substrate, and A fourth doped region in the substrate and opposite the third doped region in a second direction perpendicular to the first direction, a second undoped region of the substrate separating the third doped region from the fourth doped region.
17. 17. The apparatus of claim 16, comprising a fifth doped region extending from the first surface of the substrate to the second surface of the substrate, the fifth doped region contacting the first doped region, and the fifth doped region having a portion extending in the first direction adjacent the first surface of the substrate, the fourth doped region opposite the portion of the fifth doped region.
18. 18. The apparatus of claim 17, comprising an insulating layer on the fifth doped region.
19. 19. The apparatus of claim 16, wherein the fourth doped region is n-doped.
20. 20. The apparatus of claim 16, wherein the first doped region, the second doped region, and the third doped region are p-doped.

Description

Electronic equipment Technical Field The present disclosure relates generally to electronic devices, and more particularly to electronic devices including single photon avalanche diodes and methods of manufacturing the same. Background Single Photon Avalanche Diodes (SPADs) are solid state photodetectors in the same family as photodiodes and Avalanche Photodiodes (APDs), while also having fundamental relevance to basic diode behavior. Like photodiodes and APDs, SPADs are based on semiconductor PN junctions that can be irradiated with ionizing radiation. The fundamental difference between SPADs and APDs or photodiodes is that SPADs are biased well above their reverse bias breakdown voltage and have a structure that allows operation without damage or excessive noise. Disclosure of Invention One embodiment provides an electronic device comprising a single photon avalanche diode comprising a PN junction having a first dimension less than 1.2 μm surrounded by an insulating wall, the first dimension being a minimum dimension of the junction. Another embodiment provides a method of manufacturing an electronic device comprising a single photon avalanche diode comprising a PN junction, the method comprising a doping step for manufacturing at least part of an anode of the single photon avalanche diode, the PN junction having a first dimension smaller than 1.2 μm, the single photon avalanche diode being surrounded by an insulating wall, the first dimension being a minimum dimension of the junction. According to one embodiment, the insulating wall comprises a conductive core and an insulating sheath (shaping). According to one embodiment, a cathode of a single photon avalanche diode includes an N doped region in a substrate, an anode of the single photon avalanche diode includes a first portion positioned relative to the cathode, and a second portion surrounding a region of the substrate separated from the cathode by the first portion. According to one embodiment, the PN junction is formed by a first portion of the anode, the cathode, and a portion of the substrate between the first portion of the anode and the cathode. According to one embodiment, the second dimension is smaller than 0.5 μm, the second dimension being the smallest dimension of the overlap between the first portion and the second portion. According to one embodiment, the first dimension is less than 150% of the lateral spatial resolution of the doping method used to form at least part of the anode of the single photon avalanche diode, for example less than 130% of the lateral spatial resolution of the doping method used to form at least part of the anode of the single photon avalanche diode. According to one embodiment, the doping method used is ion implantation of a doping element. According to one embodiment, the first dimension is greater than 90% of the lateral spatial resolution of the doping method. According to one embodiment, the lateral spatial resolution of the doping method is the minimum of the minimum dimensions of the upper surface of a region having the shape of a cuboid (rectangular parallelepiped) that allows the upper surface of the region to be planar when the region is doped. According to one embodiment, the first dimension is below 1 μm. According to one embodiment, the first dimension is between 0.7 μm and 1.2 μm. According to one embodiment, the device comprises a time of flight device of which the single photon avalanche diode is a part. According to one embodiment, the method includes the formation of a hard mask including openings having at least one of their dimensions less than 150% of the lateral spatial resolution of the doping method. According to one embodiment, the doping is from the face closest to the cathode. Drawings The above features and advantages and other features and advantages will be described in detail in the following description of particular embodiments, given by way of example and not limitation with reference to the accompanying drawings, in which: Views 1A and 1B in fig. 1 show the definition of doping lateral spatial resolution; Fig. 2 shows an embodiment of an electronic device comprising a single photon avalanche diode; views 3A to 3E in FIG. 3 show examples of breakdown probabilities in different single photon avalanche diodes, and Fig. 4 shows another embodiment of an electronic device comprising a single photon avalanche diode. Detailed Description Like features are denoted by like reference numerals throughout the figures. In particular, structural and/or functional features common to the various embodiments may have the same reference numerals and may have the same structural, dimensional, and material characteristics. For clarity, only the operations and elements of the embodiments described herein have been illustrated and described in detail. Unless otherwise indicated, when two elements are referred to as being connected together, this means a direct connection without any intervening elem