Semiconductor Components Industries, LLC

Micron Technology Incorporated

Aptina Imaging Corporation

Marc Allen Sulfridge

Swarnal Borthakur

Andrew Eugene Perkins

Ulrich C Boettiger

Brian A Vaartstra

Vladimir Korobov

Scott Donald Churchwell

Larry Duane Kinsman

Nathan Wayne Chapman

Michael Gerard Keyes

Kevin W Hutto

Mitchell J Mooney

Jeffrey P Gambino

Richard A Mauritzson

David S Pratt

David T Price

Rick C Lake

Kevin McStay

Byounghee Lee

Nader Jedidi

Anne Deignan

Ryan Rettmann

Rickie C Lake

Andy Perkins

Jonathan Michael Stern

Nathan Lee

An imaging device may include single-photon avalanche diodes (SPADs). To mitigate crosstalk, isolation structures may be formed around each SPAD. The isolation structures may include front side deep trench isolation structures that extend partially or fully through a semiconductor substrate for the SPADs. The isolation structures may include a metal filler such as tungsten that absorbs photons. The isolation structures may include a p-type doped semiconductor liner to mitigate dark current. The isolation structures may include a buffer layer such as silicon dioxide that is interposed between the metal filler and the p-type doped semiconductor liner. The isolation structures may have a tapered portion or may be formed in two steps such that the isolation structures have different portions with different properties. An additional filler such as polysilicon or borophosphosilicate glass may be included in some of the isolation structures in addition to the metal filler.

Semiconductor devices with single-photon avalanche diodes and isolation structures

An imaging device may include single-photon avalanche diodes (SPADs). To improve the sensitivity and signal-to-noise ratio of the SPADs, light scattering structures may be formed in the semiconductor substrate to increase the path length of incident light through the semiconductor substrate. To mitigate crosstalk, multiple rings of isolation structures may be formed around the SPAD. An outer deep trench isolation structure may include a metal filler such as tungsten and may be configured to absorb light. The outer deep trench isolation structure therefore prevents crosstalk between adjacent SPADs. Additionally, one or more inner deep trench isolation structures may be included. The inner deep trench isolation structures may include a low-index filler to reflect light and keep incident light in the active area of the SPAD.

Semiconductor devices with single-photon avalanche diodes, light scattering structures, and multiple isolation structures

An imaging device may include single-photon avalanche diodes (SPADs). To improve the sensitivity and signal-to-noise ratio of the SPADs, light scattering structures may be formed in the semiconductor substrate to increase the path length of incident light through the semiconductor substrate. The light scattering structures may include a low-index material formed in trenches in the semiconductor substrate. One or more microlenses may focus light onto the semiconductor substrate. Areas of the semiconductor substrate that receive more light from the microlenses may have a higher density of light scattering structures to optimize light scattering while mitigating dark current.

Semiconductor devices with single-photon avalanche diodes and light scattering structures

An imaging device may include a plurality of single-photon avalanche diode (SPAD) pixels. The SPAD pixels may be overlapped by microlenses to direct light incident on the pixels onto photosensitive regions of the pixels and a containment grid with openings that surround each of the microlenses. During formation of the microlenses, the containment grid may prevent microlens material for adjacent SPAD pixels from merging. To ensure separation between the microlenses, the containment grid may be formed from material phobic to microlens material, or phobic material may be added over the containment grid material. Additionally, the containment grid may be formed from material that can absorb stray or off-angle light so that it does not reach the associated SPAD pixel, thereby reducing crosstalk during operation of the SPAD pixels.

Microlens structures for semiconductor device with single-photon avalanche diode pixels

An imaging device may include single-photon avalanche diodes (SPADs). To improve the sensitivity and signal-to-noise ratio of the SPADs, light scattering structures may be formed in the semiconductor substrate to increase the path length of incident light through the semiconductor substrate. To mitigate crosstalk, an isolation structure may be formed in a ring around the SPAD. The isolation structure may be a hybrid isolation structure with both a metal filler that absorbs light and a low-index filler that reflects light. The isolation structure may be formed as a single trench or may include a backside deep trench isolation portion and a front side deep trench isolation portion. The isolation structure may also include a color filtering material.

Semiconductor devices with single-photon avalanche diodes and hybrid isolation structures

An imaging device may include a plurality of single-photon avalanche diode (SPAD) pixels. The SPAD pixels may be overlapped by square toroidal microlenses to direct light incident on the pixels onto photosensitive regions of the pixels. The square toroidal microlenses may be formed as first and second sets of microlenses aligned with every other SPAD pixel and may allow the square toroidal microlenses to be formed without gaps between adjacent lenses. Additionally or alternatively, a central portion of each square toroidal microlenses may be filled by a fill-in microlens. Together, the square toroidal microlenses and the fill-in microlenses may form convex microlenses over each SPAD pixel. The fill-in microlenses may be formed from material having a higher index of refraction than material that forms the square toroidal microlenses.

Microlenses for semiconductor device with single-photon avalanche diode pixels

Semiconductor devices with single-photon avalanche diodes, light scattering structures, and multiple deep trench isolation structures

An image sensor package may include a semiconductor wafer having a pixel array, a color filter array (CFA) formed over the pixel array, and one or more lenses formed over the CFA. A light block layer may couple over the semiconductor wafer around a perimeter of the lenses and an encapsulation layer may be coupled around the perimeter of the lenses and over the light block layer. The light block layer may form an opening providing access to the lenses. A mold compound layer may be coupled over the encapsulation layer and the light block layer. A temporary protection layer may be used to protect the one or more lenses from contamination during application of the mold compound and/or during processes occurring outside of a cleanroom environment.

Image sensor packages formed using temporary protection layers and related methods

Semiconductor devices with single-photon avalanche diodes and light scattering structures with different densities

Implementations of image sensors may include: a first die including a plurality of detectors adapted to convert photons to electrons; a second die including a plurality of transistors, passive electrical components, or both transistors and passive electrical components; a third die including analog circuitry, logic circuitry, or analog and logic circuitry. The first die may be hybrid bonded to the second die, and the second die may be fusion bonded to the third die. The plurality of transistors, passive electrical components, or transistors and passive electrical components of the second die may be adapted to enable operation of the plurality of detectors of the first die. The analog circuitry, logic circuitry, and analog circuitry and logical circuitry may be adapted to perform signal routing.

Die stacked image sensors and related methods

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Boise, ID, United States of America

Marc Allen Sulfridge