Abstract: A self-aligned plug may be formed between deep trench isolation (DTI) etching cycles. Accordingly, etch depth in areas of a pixel sensor with large CDs (e.g., at an X-road) is reduced, which prevents trench loading. As a result, a floating diffusion (FD) region, associated with photodiodes of the pixel sensor, is not damaged during the DTI etching cycles. Reduced chances of damage to the FD region improves performance of the pixel sensor and prevents electrical shorts and failures, which increases yield and conserves time and raw materials used in forming the pixel sensor.

Abstract: Various embodiments of the present disclosure are directed towards a semiconductor structure including a photodetector disposed within a substrate. A grid structure is disposed over the substrate and the photodetector. A conductive layer is disposed between the grid structure and the substrate. A conductive contact extends into an upper surface of the substrate. The conductive layer is directly electrically coupled to the conductive contact.

Abstract: Trenches in which to form a back side isolation structure for an array of CMOS image sensors are formed by a cyclic process that allows the trenches to be kept narrow. Each cycle of the process includes etching to add a depth segment to the trenches and coating the depth segment with an etch-resistant coating. The following etch step will break through the etch-resistant coating at the bottom of the trench but the etch-resistant coating will remain in the upper part of the trench to limit lateral etching and substrate damage. The resulting trenches have a series of vertically spaced nodes. The process may result in a 10% increase in photodiode area and a 30-40% increase in full well capacity.

Abstract: In some embodiments, the present disclosure relates to an integrated chip having an inter-layer dielectric (ILD) structure along a first surface of a substrate having a photodetector. An etch stop layer is over the ILD structure, and a reflector is surrounded by the etch stop layer and the ILD structure. The reflector has a curved surface facing the substrate at a location directly over the photodetector. The curved surface is coupled between a first sidewall and a second sidewall of the reflector. The reflector has larger thicknesses along the first sidewall and the second sidewall than at a center of the reflector between the first sidewall and the second sidewall.

Abstract: A backside illumination (BSI) image sensor and a method of forming the same are provided. A device includes a substrate and a plurality of photosensitive regions in the substrate. The substrate has a first side and a second side opposite to the first side. The device further includes an interconnect structure on the first side of the substrate, and a plurality of recesses on the second side of the substrate. The plurality of recesses extend into a semiconductor material of the substrate.

Abstract: A method of fabricating self-aligned grids in a BSI image sensor is provided. The method includes depositing a first dielectric layer over a back surface of a substrate that has a plurality of photodiodes formed therein, forming a grid of trenches, and filling in the trenches with dielectric material to create a trench isolation grid. Here, a trench passes through the first dielectric layer and extends into the substrate. The method further includes etching back dielectric material in the trenches to a level that is below an upper surface of the first dielectric layer to form recesses overlaying the trench isolation grid, and filling in the recesses with metallic material to create a metallic grid that is aligned with the trench isolation grid.

Abstract: The present disclosure relates to an image sensor having a photodiode surrounded by a back-side deep trench isolation (BDTI) structure, and an associated method of formation. In some embodiments, a plurality of pixel regions is disposed within an image sensing die and respectively comprises a photodiode configured to convert radiation into an electrical signal. The photodiode comprises a photodiode doping column with a first doping type surrounded by a photodiode doping layer with a second doping type that is different than the first doping type. A BDTI structure is disposed between adjacent pixel regions and extending from the back-side of the image sensing die to a position within the photodiode doping layer. The BDTI structure comprises a doped liner with the second doping type and a dielectric fill layer. The doped liner lines a sidewall surface of the dielectric fill layer.

Abstract: Various embodiments of the present application are directed to a method for forming a thin semiconductor-on-insulator (SOI) substrate without implantation radiation and/or plasma damage. In some embodiments, a device layer is epitaxially formed on a sacrificial substrate and an insulator layer is formed on the device layer. The insulator layer may, for example, be formed with a net charge that is negative or neutral. The sacrificial substrate is bonded to a handle substrate, such that the device layer and the insulator layer are between the sacrificial and handle substrates. The sacrificial substrate is removed, and the device layer is cyclically thinned until the device layer has a target thickness. Each thinning cycle comprises oxidizing a portion of the device layer and removing oxide resulting from the oxidizing.

Abstract: Various embodiments of the present disclosure are directed towards an integrated chip including an optical device within or on a semiconductor substrate. A light guide structure overlies the optical device. A first etch stop layer extends along first sidewalls and a lower surface of the light guide structure. A second etch stop layer overlies the first etch stop layer and extends along second sidewalls of the light guide structure.

Abstract: Various embodiments of the present disclosure are directed towards an image sensor. The image sensor comprises a plurality of photodetectors disposed within a substrate. A metal grid layer is disposed over the substrate. The metal grid layer comprises a metal grid structure overlying a central pixel region of the substrate. The metal grid layer continuously extends from the central pixel region to a peripheral pixel region of the substrate that laterally encloses the central pixel region. An upper metal structure is disposed over the metal grid layer. The upper metal structure overlies the peripheral pixel region. The upper metal structure is laterally offset from the metal grid structure. A lower surface of the upper metal structure is disposed vertically over an upper surface of the metal grid structure.

Abstract: Various embodiments of the present application are directed towards a method for forming a semiconductor-on-insulator (SOI) substrate with a thick device layer and a thick insulator layer. In some embodiments, the method includes forming an insulator layer covering a handle substrate, and epitaxially forming a device layer on a sacrificial substrate. The sacrificial substrate is bonded to a handle substrate, such that the device layer and the insulator layer are between the sacrificial and handle substrates, and the sacrificial substrate is removed. The removal includes performing an etch into the sacrificial substrate until the device layer is reached. Because the device layer is formed by epitaxy and transferred to the handle substrate, the device layer may be formed with a large thickness. Further, because the epitaxy is not affected by the thickness of the insulator layer, the insulator layer may be formed with a large thickness.

Abstract: Various embodiments of the present application are directed towards a method for forming a semiconductor-on-insulator (SOI) substrate with a thick device layer and a thick insulator layer. In some embodiments, the method includes forming an insulator layer covering a handle substrate, and epitaxially forming a device layer on a sacrificial substrate. The sacrificial substrate is bonded to a handle substrate, such that the device layer and the insulator layer are between the sacrificial and handle substrates, and the sacrificial substrate is removed. The removal includes performing an etch into the sacrificial substrate until the device layer is reached. Because the device layer is formed by epitaxy and transferred to the handle substrate, the device layer may be formed with a large thickness. Further, because the epitaxy is not affected by the thickness of the insulator layer, the insulator layer may be formed with a large thickness.

Abstract: Various embodiments of the present disclosure are directed towards an image sensor. The image sensor includes a plurality of photodetectors disposed within a substrate, and the plurality of photodetectors includes a first active photodetector and a black level correction (BLC) photodetector. A metal grid structure surrounds the first active photodetector along a periphery of the first active photodetector on a first side of the substrate. A recessed blocking structure covers the BLC photodetector on the first side of the substrate. The recessed blocking structure includes both a first blocking layer inset into the first side of the substrate and a second blocking layer directly over the first blocking layer.

Abstract: A method of fabricating self-aligned grids in a BSI image sensor is provided. The method includes depositing a first dielectric layer over a back surface of a substrate that has a plurality of photodiodes formed therein, forming a grid of trenches, and filling in the trenches with dielectric material to create a trench isolation grid. Here, a trench passes through the first dielectric layer and extends into the substrate. The method further includes etching back dielectric material in the trenches to a level that is below an upper surface of the first dielectric layer to form recesses overlaying the trench isolation grid, and filling in the recesses with metallic material to create a metallic grid that is aligned with the trench isolation grid.

Abstract: Various embodiments of the present disclosure are directed towards a method for forming an image sensor. The method includes forming a photodetector in a substrate. A lower interconnect portion of an interconnect structure is formed over the photodetector. A removal process is performed to define a first opening overlying the photodetector in the lower interconnect portion. A lower etch stop layer is formed lining the first opening. The lower etch stop layer has a U-shape in the first opening. An upper interconnect portion of the interconnect structure is formed over the lower etch stop layer. A light pipe structure is formed overlying the photodetector. The U-shape of the lower etch stop layer extends continuously along sidewalls and a bottom surface of the light pipe structure.

Abstract: Various embodiments of the present disclosure are directed towards an image sensor. The image sensor comprises a plurality of photodetectors disposed within a substrate. A metal grid layer is disposed over the substrate. The metal grid layer comprises a metal grid structure overlying a central pixel region of the substrate. The metal grid layer continuously extends from the central pixel region to a peripheral pixel region of the substrate that laterally encloses the central pixel region. An upper metal structure is disposed over the metal grid layer. The upper metal structure overlies the peripheral pixel region. The upper metal structure is laterally offset from the metal grid structure. A lower surface of the upper metal structure is disposed vertically over an upper surface of the metal grid structure.

Abstract: Various embodiments of the present disclosure are directed towards a method for forming a bipolar junction transistor (BJT). A dielectric film is deposited over a substrate and comprises a lower dielectric layer, an upper dielectric layer, and an intermediate dielectric layer between the lower and upper dielectric layers. A first semiconductor layer is deposited over the dielectric film and is subsequently patterned to form an opening exposing the dielectric film. A first etch is performed into the upper dielectric layer through the opening to extend the opening to the intermediate dielectric layer. Further, the first etch stops on the intermediate dielectric layer and laterally undercuts the first semiconductor layer. Additional etches are performed to extend the opening to the substrate. A lower base structure and an emitter are formed stacked in and filling the opening, and the first semiconductor layer is patterned to form an upper base structure.

Abstract: The present disclosure describes a semiconductor device having radiation-sensing regions separated by trench isolation structures. The semiconductor structure includes a first trench fill structure on a substrate and a second trench fill structure on the substrate. The first trench fill structure has a first width and a convex bottom surface. The second trench fill structure has a concave bottom surface and a second width greater than the first width.

Abstract: In some embodiments, the present disclosure relates to an integrated chip (IC) including a conductive structure disposed within a dielectric structure along a first side of a semiconductor substrate, an insulating structure disposed along inner sidewalls of the semiconductor substrate, the inner sidewalls of the semiconductor substrate extending through the semiconductor substrate, a blocking layer disposed along inner sidewalls of the insulating structure, and a through-substrate via (TSV) comprising a first portion and a second portion, the first portion extending from a second side of the semiconductor substrate to a horizontally-extending surface of the insulating structure that protrudes outward from the inner sidewalls of the insulating structure, the second portion extending from the first portion to the conductive structure and has a maximum width less than that of the first portion.

Abstract: Various embodiments of the present disclosure are directed towards an image sensor having a photodetector disposed within a substrate. The substrate has a front-side surface and a back-side surface. An absorption enhancement structure is disposed along the back-side surface of the substrate and overlies the photodetector. The absorption enhancement structure includes a plurality of protrusions that extend outwardly from the back-side surface of the substrate. Each protrusion comprises opposing curved sidewalls.