CN-116075938-B - Optical component and image sensor including the same

Abstract

In an exemplary embodiment, an optical component includes a dielectric structure having a substantially rectangular cross-section and upper and lower surfaces. A first conductive layer is disposed on the upper surface, wherein the first conductive layer has a first opening positioned to receive incident electromagnetic radiation. The second conductive layer has a second opening positioned to emit electromagnetic radiation, for example, toward a CMOS sensor pixel in the silicon substrate. The optical component is sized to provide constructive interference for incident radiation of a selected wavelength.

Inventors

• B. Wajis
• Oksana sramkova
• LAURENT BLOND
• Walter Drazick

Assignees

• 交互数字CE专利控股有限公司

Dates

Publication Date

20260505

Application Date

20210722

Priority Date

20200730

Claims (17)

1. 1. An optical component, the optical component comprising: A dielectric structure having at least one side surface, an upper surface and a lower surface, the at least one side surface being open to receive incident electromagnetic radiation; A first conductive layer on the upper surface, the first conductive layer having a first opening positioned to receive incident electromagnetic radiation, and A second conductive layer on the lower surface, the second conductive layer having a second opening positioned to emit electromagnetic radiation; The dielectric structure is configured such that, for electromagnetic radiation of a selected wavelength, waves entering the dielectric structure through the first opening and through the side surface constructively interfere at the second opening.
2. 2. The optical component of claim 1, wherein the dielectric structure is substantially rectangular in cross-section.
3. 3. The optical component of claim 1 or 2, wherein the first opening and the second opening have substantially the same width.
4. 4. The optical component of claim 1 or 2, wherein the first opening and the second opening are substantially centered on the dielectric structure.
5. 5. An optical component according to claim 1 or 2, wherein the dielectric structure is mounted on a silicon substrate, the second opening being positioned to emit electromagnetic radiation into the silicon substrate.
6. 6. The optical component of claim 1 or 2, further comprising a photodetector located beneath the dielectric structure.
7. 7. The optical component of claim 1 or 2, wherein the dielectric structure has a height h Element between 1600nm and 1900nm and a width d Element between 1100nm and 1400 nm.
8. 8. An optical component according to claim 1 or 2, wherein the dielectric structure has a height h Element between 900nm and 1300nm and a width d Element between 750nm and 1050 nm.
9. 9. The optical component of claim 1 or 2, wherein the first opening and the second opening each have a width between 150nm and 200 nm.
10. 10. The optical component of claim 1 or 2, configured to selectively transmit light having a wavelength Wherein the height h Element of the dielectric structure is substantially equal to Wherein Is the refractive index and the refractive index of the dielectric structure Is the refractive index of the surrounding medium.
11. 11. An image sensor comprising a two-dimensional array of optical components according to any one of claims 1-3.
12. 12. A method for use with an optical component, the method comprising: Directing electromagnetic radiation onto an optical component, wherein the optical component comprises: A dielectric structure having at least one side surface, an upper surface and a lower surface, the at least one side surface being open to receive incident electromagnetic radiation; A first conductive layer on the upper surface, the first conductive layer having a first opening positioned to receive incident electromagnetic radiation, and A second conductive layer on the lower surface, the second conductive layer having a second opening positioned to emit electromagnetic radiation; The dielectric structure is configured such that, for electromagnetic radiation of a selected wavelength, waves entering the dielectric structure through the first opening and through the side surface constructively interfere at the second opening.
13. 13. The method for use with an optical component of claim 12, wherein the height h Element of the dielectric structure is substantially equal to Wherein Is the refractive index and the refractive index of the dielectric structure Is the refractive index of the surrounding medium, and wherein Is the wavelength of the incident electromagnetic radiation.
14. 14. The method for use with an optical component as recited in claim 12 or 13, further comprising operating a photodetector to detect an amount of electromagnetic radiation emitted through the second opening.
15. 15. The method for use with an optical component according to claim 12 or 13, wherein the dielectric structure is substantially rectangular in cross-section.
16. 16. The method for use with an optical component according to claim 12 or 13, wherein the first opening and the second opening have substantially the same width.
17. 17. The method for use with an optical component according to claim 12 or 13, wherein the dielectric structure is mounted on a silicon substrate, the second opening being positioned to emit electromagnetic radiation into the silicon substrate.

Description

Optical component and image sensor including the same Cross Reference to Related Applications The present application claims priority from european patent application number EP20305871 entitled "OPTICAL COMPONENT AND IMAGE SENSOR COMPRISING AN OPTICAL COMPONENT" filed on 7/30/2020, which application is hereby incorporated by reference in its entirety. Background This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present disclosure that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the systems and methods described herein. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. The present disclosure relates to the field of CMOS sensors. Some CMOS sensors operate based on the photoelectric effect that converts incident photons into electrical charge, thereby producing a voltage (using integrated electronics) that varies according to intensity. Some CMOS sensors are used for Near Infrared (NIR) wavelengths. Such NIR CMOS sensors have gained a growing market share and are replacing traditional CCD sensors, which may be expensive and less efficient. CMOS NIR sensors are used in digital cameras to collect data under poor lighting conditions (e.g., night time traffic management). Such sensors may also be used in security applications, personal authentication applications, and ranging applications. In practice, image sensors may use microlenses to focus incident radiation onto a photosensitive portion of the device, typically a semiconductor substrate such as silicon. Silicon has a small absorption coefficient, which requires a thick photon absorption layer, which in turn increases chip cost, because the fabrication of thick substrate CMOS sensors uses expensive fabrication equipment. Conventional CMOS sensors consist of microlenses and photosensitive portions that convert received photons into electrons. However, such optical stacks do not have filtering capability that allows only a limited band centered at one wavelength to pass through and reach the photodetector. Therefore, some sensors also use a color filter layer. Wavelength selective absorption has been proposed in the literature by using techniques such as diffractive light trapping pixels, silicon nanowires with hexagonal cross sections, and III-V semiconductor nanowires. Such systems typically require complex and expensive manufacturing techniques. Disclosure of Invention Reference in the specification to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment necessarily includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, such feature, structure, or characteristic may be used in connection with other embodiments whether or not explicitly described. An optical component according to some embodiments includes a dielectric structure having at least one side surface open to receive incident electromagnetic radiation, an upper surface and a lower surface, a first conductive layer on the upper surface having a first opening positioned to receive incident electromagnetic radiation, and a second conductive layer on the lower surface having a second opening positioned to emit electromagnetic radiation. In some embodiments, the dielectric structure is substantially rectangular in cross-section. In some embodiments, the first opening and the second opening have substantially the same width. In some embodiments, the first opening and the second opening are substantially centered on the dielectric structure. In some embodiments, the dielectric structure is mounted on a silicon substrate, and the second opening is positioned to emit electromagnetic radiation into the silicon substrate. Some embodiments further include a photodetector located below the dielectric structure. In some embodiments, the dielectric structure has a height h Element between 1600nm and 1900nm and a width d Element between 1100nm and 1400 nm. In some embodiments, the dielectric structure has a height h Element between 900nm and 1300nm and a width d Element between 750nm and 1050 nm. In some embodiments, the first opening and the second opening each have a width between 150nm and 200 nm. In some embodiments, the optical component is configured to selectively transmit incident electromagnetic radiation having a wavelength λ inc, where the height h Element of the dielectric structure is substantially equal toWhere n H is the refractive index of the dielectric structure and n L is the refr