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DE-102018124865-B4 - Light-blocking layer for an image sensor device

DE102018124865B4DE 102018124865 B4DE102018124865 B4DE 102018124865B4DE-102018124865-B4

Abstract

Image sensor (200), including: a semiconductor layer (202) having a top surface and a bottom surface, wherein the semiconductor layer (202) comprises one or more detection areas (204) designed to detect radiation (800, 802) entering the semiconductor layer (202) from the top surface; a grid structure (216) with one or more cells (218) each aligned with the one or more detection areas (204), wherein each of the one or more cells (218) of the grid structure (216) comprises a color filter (220), wherein each of the one or more cells (218) of the grid structure (216) accommodates the color filter (220) within side walls of the one or more cells (218); a transparent material layer (228) arranged over the grid structure (216), wherein the transparent material layer (228) forms a microlens (230) over each of the one or more cells (218); and a light-blocking material layer (500) arranged on the transparent material layer (228) between microlenses (230).

Inventors

  • Yun-Wei Cheng
  • Chun-Hao Chou
  • Kuo-Cheng Lee

Assignees

  • TAIWAN SEMICONDUCTOR MANUFACTURING CO. LTD.

Dates

Publication Date
20260513
Application Date
20181009
Priority Date
20180430

Claims (19)

  1. Image sensor (200) comprising: a semiconductor layer (202) with a top surface and a bottom surface, wherein the semiconductor layer (202) comprises one or more detection areas (204) designed to detect radiation (800, 802) entering the semiconductor layer (202) from the top surface; a lattice structure (216) with one or more cells (218) each oriented towards the one or more detection areas (204), wherein each of the one or more cells (218) of the grid structure (216) comprises a color filter (220), wherein each of the one or more cells (218) of the grid structure (216) accommodates the color filter (220) within side walls of the one or more cells (218); a transparent material layer (228) arranged over the grid structure (216), wherein the transparent material layer (228) forms a microlens (230) over each of the one or more cells (218); and a light-blocking material layer (500) arranged on the transparent material layer (228) between microlenses (230).
  2. Image sensor (200) after Claim 1 , which further comprises a connection structure (232) arranged below the lower surface of the semiconductor layer (202).
  3. Image sensor (200) after Claim 1 or 2 , wherein the light-blocking material layer (500) has a thickness (T5) that is 0.05 to 0.5 times smaller than a thickness (T1) of the microlens (230).
  4. Image sensor (200) according to one of the preceding claims, wherein the grid structure (216) is arranged above the upper surface of the semiconductor layer (202).
  5. Image sensor (200) according to one of the preceding claims, wherein the light-blocking material layer (500) comprises tungsten, aluminium, copper or a metal alloy.
  6. Image sensor (200) according to one of the preceding claims, wherein the light-blocking material layer (500) comprises an infrared color filter material.
  7. Image sensor (200) according to one of the preceding claims, wherein the light-blocking material layer (500) comprises silicon nitride, silicon oxynitride or silicon carbide.
  8. Semiconductor image sensor (200), comprising: a grid structure (216) with one or more cells (218) arranged over a semiconductor layer (202), the semiconductor layer (500) being arranged on a multilayer interconnect structure (234) and configured to detect radiation (800, 802) received by the grid structure (220); a color filter (220) in each of the one or more cells (218), each of the one or more cells (218) of the grid structure (216) accommodating the color filter (220) within sidewalls of the one or more cells; microlenses (230) formed over the one or more cells (218) of the grid structure (216); and a light-blocking layer (500) arranged between the microlenses (230), wherein the light-blocking layer (500) is thinner than the microlenses (230).
  9. Semiconductor image sensor (200) according to Claim 8 , wherein the semiconductor layer (202) comprises one or more detection areas (204) which are each aligned with the one or more cells (218) of the lattice structure (216).
  10. Semiconductor image sensor (200) according to Claim 8 , wherein the microlenses (230) comprise a transparent material.
  11. Semiconductor image sensor (200) according to one of the preceding Claims 8 until 10 , wherein the ratio between the thickness (T5) of the light-blocking layer (500) and the thickness (T1) of the microlenses (230) is in a range of 0.05 to 0.5.
  12. Semiconductor image sensor (200) according to one of the preceding Claims 8 until 11 , wherein the light-blocking material layer comprises (500) tungsten, aluminium, copper or a metal alloy.
  13. Semiconductor image sensor (200) according to one of the preceding Claims 8 until 12 , wherein the light-blocking layer (500) comprises an infrared color filter material.
  14. Semiconductor image sensor (200) according to one of the preceding Claims 8 until 13 , wherein the light-blocking layer (500) comprises silicon nitride, silicon oxynitride or silicon carbide.
  15. Method for manufacturing a semiconductor image sensor (200), comprising: forming a semiconductor layer (202) with a first side (206) and an opposing second side (208) and with a multilayer interconnect structure (234) coupled to the first side (206) of the semiconductor layer (202); forming, on the second side (208) of the semiconductor layer (202), a lattice structure (216) with one or more cells (218), wherein each of the one or more cells (218) of the lattice structure (216) accommodates a color filter (220) within sidewalls of the one or more cells (218); arranging a transparent layer (228) over the lattice structure (216) to form a microlens (230) aligned with each of the one or more cells (218); and forming a light-blocking layer (500) between adjacent microlenses (230), wherein forming the light-blocking layer (500) comprises: depositing the light-blocking layer (500) over the transparent layer (228); and etching the light-blocking layer (500) to block the light to remove the blocking layer (500) over the microlens (228).
  16. Procedure according to Claim 15 , wherein the deposition of the light-blocking layer (500) comprises the deposition of the light-blocking layer (500) using a physical vapor deposition (PVD) process, a chemical vapor deposition (CVD) process, an atomic layer deposition (ALD) process, a plasma-assisted CVD process, a plasma-assisted ALD process, a vapor deposition process, a focused ion beam induced deposition process, an electron beam-assisted deposition process or a rotational coating process.
  17. Procedure according to Claim 15 or 16 , wherein the etching of the light-blocking layer (500) comprises etching of the light-blocking layer (500) using dry etching or wet etching.
  18. procedure according to one of the preceding Claims 15 until 17 , wherein the light-blocking material layer comprises (500) tungsten, aluminium, copper, a metal alloy, silicon nitride, silicon oxynitride or silicon carbon.
  19. procedure according to one of the preceding Claims 15 until 18 , wherein the light-blocking material layer (500) comprises an infrared color filter material.

Description

STATE OF THE ART Semiconductor image sensors are used to detect visible and invisible radiation, such as visible light, infrared light, etc. Complementary metal-oxide-semiconductor (CMOS) image sensors (CIS sensors) and charge-coupled device sensors (CCD sensors) are used in various applications, such as digital cameras, mobile phones, tablets, eyeglasses, etc. Arrays of pixels found in CMOS and CIS devices can detect incident radiation projected onto the sensor and convert it into electrical signals. US 2013 / 0 001 724 A1 This describes a solid-state image sensor in which two lens layers, consisting of in-layer lenses and microlenses, are arranged on a semiconductor layer. A color filter layer is located between the in-layer lenses and the microlenses, in which the color filters are positioned adjacent to one another. Furthermore, a light blocker is formed at the interfaces between the adjacent microlenses, each of which is positioned above a corresponding color filter. In addition, the microlenses are each aligned with corresponding light-receiving portions in the semiconductor layer. Further prior art relating to the subject matter of the invention can be found in the printed publications. US 2016 / 0 276 394 A1 , US 2014 / 0 077 323 A1 and US 2015 / 0 243 805 A1 to find. BRIEF DESCRIPTION OF THE DRAWINGS Aspects of the present disclosure are best understood from the detailed description below, when read together with the accompanying figures. It should be noted that, in accordance with standard industry practice, various features are not drawn to scale. Rather, the dimensions of the various features may have been enlarged or reduced as appropriate for clarity of illustration and discussion. 1 is a flowchart of a method for forming an image sensor device according to some embodiments of the present disclosure. 2 is a cross-sectional view of a back-illuminated image sensor device according to some embodiments of the present disclosure. 3 is a top view of a composite grid structure designed to accommodate color filters, according to some embodiments of the present disclosure. 4 is a cross-sectional view of an enlarged upper section of a back-illuminated image sensor device according to some embodiments of the present disclosure. 5 is a cross-sectional view of a back-illuminated image sensor device after the deposition of a light-blocking material layer, according to some embodiments of the present disclosure. 6 is a cross-sectional view of an enlarged upper section of a back-illuminated image sensor device after the deposition of a light-blocking material layer, according to some embodiments of the present disclosure. 7 is a cross-sectional view of an enlarged upper section of a back-illuminated image sensor device after etching a light-blocking material layer, according to some embodiments of the present disclosure. 8 is a cross-sectional view of a back-illuminated image sensor device after etching a light-blocking material layer, according to some embodiments of the present disclosure. DETAILED DESCRIPTION The following disclosure provides many different embodiments, or examples, for implementing various features of the present subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, forming a first feature over a second feature in the description below may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features are not in direct contact. Furthermore, terms relating to spatial relativity, such as "below", "under", "lower", "above", "upper", and the like, may be used here to facilitate discussion and to describe the relationship of one element or feature to another element or feature (or to other elements or features). as illustrated in the figures. The terms relating to spatial relativity are intended to encompass various orientations of the device used or operated, in addition to the orientation shown in the figures. The device may be oriented differently (rotated by 90 degrees or otherwise), and the terms used here relating to spatial relativity may be interpreted accordingly. As used here, the term "approximately" indicates the value of a given quantity, which may vary based on a specific technology node associated with the object semiconductor device. Based on that specific technology node, the term "approximately" can indicate a value of a given quantity that varies, for example, within 10 to 30% of the value (e.g., ±10%, ±20%, or ±30% of the value). As used here, the term “essentially” indicates that the value of a given quantity varies by ±1% to ±5% of the value. In a back-illuminated image sensor device, color filters and microlenses are arranged on the back side o