Patent ID: 12199132

DETAILED DESCRIPTION

The following describes the technology of this disclosure within the context of an autonomous vehicle for example purposes only. As described herein, the technology is not limited to an autonomous vehicle and can be implemented within other robotic and computing systems as well as various devices. For example, the systems and methods disclosed herein can be implemented in a variety of ways including, but not limited to, a computer-implemented method, an autonomous vehicle system, an autonomous vehicle control system, a robotic platform system, a general robotic device control system, a computing device, etc.

With reference toFIGS.1A-10, example implementations of the present disclosure are discussed in further detail.FIG.1Ais a perspective view of an exemplary semiconductor wafer1relative to a semiconductor boule2from which semiconductor wafers for use in the disclosed semiconductor optical devices and related manufacturing methods may be sliced.FIG.1Bis a simplified cross-sectional view of the semiconductor wafer1ofFIG.1Asuperimposed over a portion of a semiconductor boule2.

Semiconductor wafer1and semiconductor boule2may correspond to various crystalline materials such as, but not limited, to silicon. In certain embodiments, single crystal silicon and polycrystalline silicon varieties may be utilized. Intentionally or unintentionally doped silicon may be utilized to form semiconductor boule2and semiconductor wafer1. In addition, silicon or other crystalline materials used to form semiconductor boule2and semiconductor wafer1may have various on-axis and off-axis crystallographic orientations. Although semiconductor wafer1is shown as a generally circular wafer cut from a generally cylindrical semiconductor boule, it should be appreciated that wafers may be cut from different boules such as those shaped as a cube, rectangular prism, hexagonal cylinder, or other three-dimensional shapes.

As known to those of ordinary skill in art, the crystalline growth structure of silicon may generally be referenced with respect to crystallographic orientation directions. For example, the [100], [110], and directions are crystallographic directions in a crystal lattice of a silicon wafer, while the (100), (110), and (111) planes are corresponding planes associated with such directions. The set of three integers used to define the orientation of the respective crystallographic planes and directions correspond to Miller indices, which are indicative of respective intercepts of the plane or direction on the axes for a given combination. For example, in a silicon wafer, the (100) plane is a crystal plane that is perpendicular to the direction, which is a line parallel to the y-axis of the crystal lattice. The (110) plane is a crystal plane that is perpendicular to the direction, which is a line at a 45-degree angle to the x- and y-axes of the crystal lattice. The (111) plane is a crystal plane that is perpendicular to the direction, which is a line at a 54.7-degree angle to the x-, y-, and z-axes of the crystal lattice.

Referring still toFIGS.1A and1B, semiconductor boule2is considered to have a particular orientation such that the boule end face3is oriented along the (110) plane within the crystal lattice structure of the silicon boule2. Semiconductor wafers cut parallel to the boule end face3would correspond to (110) semiconductor wafers. In some embodiments of the disclosed technology, (110) silicon wafers cut from semiconductor boule2in such fashion may be employed. In other embodiments, a semiconductor wafer1is cut from semiconductor boule2at a particular slicing angle5. The slicing angle5may be chosen in a manner to facilitate formation of notch structures within the semiconductor wafer1as described herein. In some implementations, the slicing angle is chosen in a range from about 5 to about 15 degrees, or about 10 degrees, or about 9.7 degrees relative to the (110) plane of the crystalline structure forming semiconductor boule2. In other words, the wafer face4of semiconductor wafer1is rotated relative to the boule end face3of the semiconductor boule2by slicing angle5.

FIGS.2A-2Irespectively depict aspects of semiconductor wafer fabrication in a manufacturing process for semiconductor optical devices according to some implementations of the present disclosure.FIGS.2A-2Idepict only part of a two-dimensional segment of a semiconductor wafer and associated structures fabricated thereon. It should be appreciated that a greater or fewer number of structures (e.g., microlens structures, notch structures, etc.) may be formed on a semiconductor wafer in multiple dimensions (e.g., first and second dimensions) on a surface of the depicted semiconductor wafers.

Referring first toFIG.2A, a semiconductor wafer1may be provided as part of the disclosed manufacturing process. In some examples, the semiconductor wafer1depicted inFIG.2Amay be the same as semiconductor wafer1depicted inFIGS.1A and1B. In one example, semiconductor wafer1ofFIG.2Amay include silicon. Semiconductor wafer1ofFIG.2Amay include a first major surface10and a second major surface11opposing the first major surface10. First major surface10and second major surface11may be substantially parallel (e.g., ±5 degrees of one another). As also described relative toFIGS.1A-1B, first major surface10and second major surface11may be cut from a semiconductor boule (e.g., semiconductor boule2) at a particular slicing angle such that the first major surface10and/or the second major surface11of the semiconductor wafer1is oriented in a range from about 5 to about 15 degrees (e.g., about 10 degrees or about 9.7 degrees) relative to the (110) plane of the crystalline structure forming the semiconductor boule.

Referring now toFIGS.2B-2C, a plurality of microlens structures12may be formed at respective first locations13on the first major surface10of the semiconductor wafer1. In some examples, the respective first locations13and corresponding microlens structures12may be fabricated in a single linear arrangement (e.g., a one-dimensional array). In other examples, the respective first locations13and corresponding microlens structures12may be fabricated in a plurality of linear arrangements (e.g., a two-dimensional array) on the first major surface10of the semiconductor wafer1.

In some examples, the plurality of microlens structures12may be formed at the respective first locations13using a dry-etch process (e.g., reactive-ion etching). For instance, a pattern14may be formed on the first major surface10of the semiconductor wafer1. The pattern14may be formed to define a plurality of generally circular or rounded openings corresponding to the respective first locations13. In some examples, a photolithography process may be employed to form the pattern14on the first major surface10of the semiconductor wafer1. For example, a photosensitive material (e.g., a photoresist) may be applied to the first major surface10of the semiconductor wafer1. A photomask formed to define the pattern14may then be placed over the photosensitive material. Light may be provided from a light source (e.g., an ultraviolet (UV) light source, deep UV light source, extreme UV light source, X-ray light source, etc.) When light is provided to the photomask, the photosensitive material is exposed in certain areas, causing the exposed areas to undergo a chemical change, making them either soluble or insoluble in a development solution. After development, the pattern14is transferred onto the first major surface10of the semiconductor wafer1through one or more processes, such as etching, chemical vapor deposition, or an ion implantation process.

Referring still toFIGS.2B-2C, respective portions of lens material15may be deposited at the respective first locations13now defined by the pattern14. In some examples, lens material15may include one or more of a polymer material, polypropylene, polystyrene, acrylic resin (PMMA), polycarbonate (PC), polyetherimide (PEI), cyclo-olefin polymer (COP), cyclo-olefin co-polymer (COC), methyl pentene, acrylonitrile butadiene styrene (ABS), ophthalmic material, glass material, thermoplastic material, or other suitable material. Lens material15may be deposited in generally cylindrical portions at the respective first locations13defined by the pattern14. The respective portions of lens material15are then heated to shape the lens material15into the plurality of microlens structures12. For example, the heat can cause the lens material15to swell and transform into respective dome-shaped structures or hemispherical structures corresponding to the respective microlens structures12. After this, the wafer assembly ofFIG.2Bmay be subjected to a reactive-ion etching (RIE) process, such as a process that exposes the wafer assembly to a chemically reactive plasma in a wafer processing chamber to remove the pattern14. Plasma may be generated, for example, in the wafer processing chamber under low pressure by an electromagnetic field. High-energy ions from the plasma attack the first major surface10and react with it to remove pattern14.

Referring now toFIGS.2D-2F, the disclosed manufacturing process may further involve forming a plurality of notch structures22at respective second locations20on the second major surface11of the semiconductor wafer1. The respective second locations20on the second major surface11may be substantially opposite (e.g., within about 1-20 microns of a common axis through the first major surface10and the second major surface11of the semiconductor wafer1) the respective first locations13on the first major surface10. The notch structures22can include angled surfaces26formed as a V-groove between pattern24in the second major surface11. In some embodiments, such as depicted inFIGS.2D-2E, each notch structure22includes a first angled surface26′ and a second angled surface26″. The first angled surface26′ and the second angled surface26″ are formed to have angles relative to the second major surface11in a range of between about 40 degrees and about 50 degrees (e.g., about 45 degrees), between about 30 degrees and about 60 degrees, or between about 20 degrees and about 70 degrees. Respective first angled surfaces26′ on the second major surface11may be substantially opposite a respective first microlens structures12′ on the first major surface, while respective second angled surfaces26″ on the second major surface11may be substantially opposite respective second microlens structures26″ on the second major surface11.

In some implementations, the plurality of notch structures22including first angled surfaces26′ and second angled surfaces26″ may be formed at the respective second locations20using a wet-etch process (e.g., anisotropic Silicon etching). For instance, a pattern24may be formed on the second major surface11of the semiconductor wafer1. The pattern24may be formed to define a plurality of openings corresponding to the respective second locations20. In some examples, a photolithography process may be employed to form the pattern24on the second major surface11of the semiconductor wafer1. For example, a photosensitive material (e.g., a photoresist) may be applied to the second major surface11of the semiconductor wafer1. A photomask formed to define the pattern24may then be placed over the photosensitive material. Light may be provided from a light source (e.g., an ultraviolet (UV) light source, deep UV light source, extreme UV light source, X-ray light source, etc.) When light is provided to the photomask, the photosensitive material is exposed in certain areas, causing the exposed areas to undergo a chemical change, making them either soluble or insoluble in a development solution. After development, the pattern24is transferred onto the second major surface11of the semiconductor wafer1through one or more processes, such as etching, chemical vapor deposition, or an ion implantation process. In some embodiments (although not illustrated), the pattern24is also formed along the entirety of the first major surface10including the microlens structures12to protect them during the wet-etch process of forming notch structures22.

Referring still toFIGS.2D-2F, a wet-etch process may then be employed to selectively remove material from the semiconductor wafer1at exposed locations among pattern24on the second major surface11. For example, the semiconductor wafer1including pattern24may be exposed to an etching solution that selectively removes material from the semiconductor wafer. The semiconductor material removal may cause material removal in planar directions, creating well-defined features with sharp corners and edges, such as the first angled surface26′ and second angled surface26″ of notch structures22. When semiconductor wafer1includes a silicon wafer, an anisotropic etching solution may be used such as a solution that contains one or more of: potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH), nitric acid and hydrofluoric acid (HNO3/HF), etc. An anisotropic etching solution may remove material from the (111) planes of the silicon wafer, creating features corresponding to the notch structure22. Pattern24may also be removed to form a semiconductor wafer30as depicted inFIG.2F.

Referring now toFIGS.2G-2I, the disclosed manufacturing process may further involve additional steps to transform multiple semiconductor wafers30into a plurality of individual semiconductor optical devices. For instance, as shown inFIG.2G, one or more coatings may be applied to one or more surfaces of the semiconductor wafer30. For example, an anti-reflective coating31may be applied to the first major surface10of the semiconductor wafer30including the plurality of microlens structures12. The anti-reflective coating31may include magnesium fluoride, silicon dioxide, dielectric coatings, and the like. Additionally or alternatively, a metal coating32may be applied to the second major surface11of the semiconductor wafer30including the plurality of notch structures22such that respective first angled surfaces26′ and26″ have metal coating32thereon to facilitate function as a turning mirror as later described herein. In some implementations, an adhesive coating (e.g., silicon oxide, silicon nitride, a dielectric coating, etc.) is first applied to the angled surfaces26′,26″ underneath the metal coating32(e.g., aluminum, chromium, anodized chromium or black chrome, etc.) to facilitate adhesion of the metal coating32to the silicon or other material forming semiconductor wafer30.

Referring now toFIG.2H, a first semiconductor wafer30aand a second semiconductor wafer30bmay be adhered together to form a semiconductor wafer pair40. More particularly, a second major surface11aof the first semiconductor wafer30amay be adhered to a second major surface11bof the second semiconductor wafer30bwith a bonding layer42. The first and second semiconductor wafers30aand30bmay be aligned by aligning one or more opposing features. For instance, first notch structures22aof the first semiconductor wafer30amay be aligned substantially opposite second notch structures22bof the second semiconductor wafer30b. Additionally or alternatively, first microlens structures12aof the first semiconductor wafer30amay be aligned substantially opposite second microlens structures12bof the second semiconductor wafer30b. Additionally or alternatively, portions of the second major surface11aof the first semiconductor wafer30abetween respective first notch structures22amay be aligned substantially opposite portions of the second major surface11bof the second semiconductor wafer30bbetween respective first notch structures22b. These opposing portions of the second major surfaces11aand11bmay be adhered together with a bonding layer42.

Referring now toFIG.2I, the semiconductor wafer pair40ofFIG.2Hmay be diced along dicing lines43to form a plurality of individual semiconductor optical devices44. In some examples, dicing along a dicing line43may correspond to dicing the first semiconductor wafer30aat a first vertex27aof a first notch structure22aand the second semiconductor wafer30bat a second vertex27bof a second notch structure22b. Prior to dicing, in some implementations, individual semiconductor optical devices44can be isolated from one another by one or more respective deep ridge etches (not illustrated) formed on the first major surfaces10of the respective semiconductor wafers30. Such deep ridge etches may be formed, for example, using the same or similar dry etch process used to form the respective microlens structures12. For example, a plurality of deep ridge etches may be formed on the first major surface10aof the first semiconductor wafer30asuch that a respective deep ridge etch is formed between adjacent microlens structures12a. Similarly, a plurality of deep ridge etches may be formed on the first major surface10bof the second semiconductor wafer30bsuch that a respective deep ridge etch is formed between adjacent microlens structures12b. The semiconductor wafer pair40may then be diced along respective deep ridge etches to form a plurality of individual semiconductor optical devices44.

In some examples, after dicing along dicing lines43as indicated inFIG.2H, additional operations may be applied to the individual semiconductor optical devices44. For example, an outer surface of the individual semiconductor optical devices44where diced (e.g., at the dicing lines43) may be smoothed (e.g., by grinding, polishing, lapping, etc.). Smoothing of such surfaces can help to facilitate directing beams (e.g., transmitting and/or receiving beams) in and/or out of the semiconductor optical devices44. Additionally or alternatively, an anti-reflective coating may be applied to the outer surface of the individual semiconductor optical devices44where diced and optionally smoothed at the dicing lines43.

FIG.3depicts a semiconductor optical device100, according to some implementations of the disclosure. The semiconductor optical device100can be fabricated using the manufacturing operations described herein, and may correspond for example, to the semiconductor optical devices44formed inFIG.2H. Semiconductor optical device100can be included in a LIDAR system, such as the LIDAR system150ofFIG.4, the LIDAR system200ofFIG.5(e.g., as part of the transceiver230), and the like.

InFIG.3, the semiconductor optical device100may include two portions, for example a first portion110and a second portion120. The first portion110and the second portion120may be respectively fabricated using a semiconductor material, such as silicon, glass, polymer, doped plastic, or other suitable material. In some implementations, the first portion110and the second portion120may be combined or integrated together as a single device. For example, the first portion110and the second portion120may be joined together via a metal coating140or other bonding layer. The metal coating140may be configured or formed of a material to prevent an outgoing light119from mixing with an incoming light129. In some implementations, the semiconductor optical device100may include two bonded monolithic silicon microlens arrays (e.g., corresponding to the first portion110and the second portion120, respectively) that each have integrated turning mirrors. For example, the semiconductor optical device100can include respective portions from the first and second semiconductor wafers30aand30bofFIG.2H.

The first portion110includes a first microlens structure114, a first angled surface115, and a first beam directing portion116. The outgoing light119may enter the first microlens structure114at a first location112and be reflected by the first angled surface115(which acts as a mirror) at a second location117, and then be transmitted out of the first beam directing portion116at a third location118to an environment (e.g., toward an object). The outgoing light119may reflect off an object in the environment and be reflected back toward the semiconductor optical device100. The light which is reflected off the object and back toward the semiconductor optical device100may correspond to the incoming light129.

The second portion120includes a second microlens structure124, a second angled surface125, and a second beam directing portion126. The incoming light129may enter the second beam directing portion126at a fourth location128and be reflected by the second angled surface125(which acts as a mirror) at a fifth location127, and then be transmitted out of the second microlens structure124at a sixth location122to an environment (e.g., toward a receiver such as receiver168inFIG.4).

The first microlens structure114may include an integrated optical lens that is configured to direct (e.g., collimate) the outgoing light119that is transmitted along a first direction x1and enters at the first location112and focuses the outgoing light119onto the first angled surface115where it is reflected in a second direction x2toward the first beam directing portion116. For example, the first microlens structure114may include a spherical lens, a cylindrical lens, an elliptical lens, and the like. In some implementations, the first microlens structure114may be formed of a silicon material, a polymer plastic material, etc. In some implementations, the first microlens structure114may include an anti-reflective coating which is configured or formed to minimize reflection and increase light transmission through the first microlens structure114. The anti-reflective coating may include magnesium fluoride, silicon dioxide, dielectric coatings, and the like. The anti-reflective coating on first microlens structure114may correspond, for example, to the anti-reflective coating31depicted inFIG.2G.

The second location117of the first angled surface115may be configured to receive the outgoing light119which is transmitted along the first direction x1and direct the outgoing light119in the second direction x2toward the third location118of the first beam directing portion116. In some implementations, the first direction x1and the second direction x2may be perpendicular to one another, or substantially perpendicular (e.g., ±10 degrees). In some implementations, the first angled surface115may be configured to redirect or reflect the outgoing light119by internal reflection. In some implementations, the first angled surface115may include or be formed of a material which is configured to redirect or reflect the outgoing light119. For example, a metal layer may be provided at an outer side of the first angled surface115such that the first angled surface115is configured to function as a mirror. For example, an anti-reflective layer may be provided at an outer side of the first angled surface115. For example, the first angled surface115may be configured to be angled with respect to the first direction x1by a predetermined angle α134. In some implementations, the predetermined angle α134may be about 45 degrees. In some implementations, the predetermined angle α134may be between about 40 degrees and about 50 degrees, between about 30 degrees and about 60 degrees, or between about 20 degrees and about 70 degrees.

The first beam directing portion116may be configured to receive the outgoing light119which is transmitted along the second direction x2to the third location118and direct the outgoing light119in the second direction x2toward an environment (e.g., toward an object in the environment, toward a sensor, etc.). In some implementations, the first beam directing portion116may be formed of a silicon material, a polymer plastic material, etc. In some implementations, the first beam directing portion116may include an anti-reflective coating which is configured or formed to minimize reflection and increase light transmission through the first beam directing portion116. The anti-reflective coating may include magnesium fluoride, silicon dioxide, dielectric coatings, and the like. The anti-reflective coating applied to the first beam directing portion116may be applied to such associated surface of the semiconductor optical device100after dicing as described inFIG.2Iand surface smoothing (e.g., by grinding, polishing, lapping, etc.)

As mentioned above, the outgoing light119may reflect off an object in the environment and be reflected back toward the semiconductor optical device100. The light which is reflected off the object and back toward the semiconductor optical device100may correspond to the incoming light129. For example, the second beam directing portion126may be configured to receive the incoming light129which is transmitted along a third direction x3at a fourth location128and direct the incoming light129in the third direction x3toward a fifth location127at the second angled surface125. In some implementations, the fourth location128and third location118may be separated from each other by a distance d132. In some implementations, the outgoing light119and the incoming light129may be separated from each other by the distance d132. For example, the distance d132may be about 100 μm, for example, about 80 μm to about 120 μm. In some implementations, the outgoing light119and the incoming light129may be parallel to one another or substantially parallel to one another (e.g., within ±5 degrees, ±10 degrees, etc.).

In some implementations, the second beam directing portion126may be formed of a silicon material, a polymer plastic material, etc. In some implementations, the second beam directing portion126may include an anti-reflective coating which is configured or formed to minimize reflection and increase light transmission through the second beam directing portion126. The anti-reflective coating may include magnesium fluoride, silicon dioxide, dielectric coatings, and the like. The anti-reflective coating applied to the second beam directing portion126may be applied to such associated surface of the semiconductor optical device100at the same time as applying the anti-reflective coating to the first beam direction portion116, namely, after dicing as described inFIG.2Iand surface smoothing (e.g., by grinding, polishing, lapping, etc.)

For example, the fifth location127at the second angled surface125may be configured to receive the incoming light129which is transmitted along the third direction x3and direct the incoming light129in the second direction x2toward a sixth location122at the second microlens structure124. In some implementations, the first direction x1and the third direction x3may be perpendicular to one another, or substantially perpendicular (e.g., ±10 degrees). In some implementations, the second angled surface125may be configured to redirect or reflect the incoming light129by internal reflection. In some implementations, the second angled surface125may include or be formed of a material which is configured to redirect or reflect the incoming light129. For example, the first portion110(e.g., the first angled surface115which acts as a first mirror) and the second portion120(e.g., the second angled surface125which acts as a second mirror) may be joined together at a location which forms a notch and corresponds to the metal coating140, particularly where the first and second mirrors (e.g., the first angled surface115and the second angled surface125) intersect. In other words, the first angled surface115and the second angled surface125may be positioned at opposing angles relative to one another and meet at a vertex141between the first portion110and the second portion120.

For example, a metal layer may be provided at an outer side of the second angled surface125such that the second angled surface125is configured to function as a mirror. The interior portion136formed between the first angled surface115and the second angled surface125may be hollow and/or composed of air. For example, an anti-reflective layer may be provided at an outer side of the second angled surface125. For example, the second angled surface125may be configured to be angled with respect to the first direction x1by a predetermined angle α134. In some implementations, the predetermined angle α134may be between about 40 degrees and about 50 degrees, between about 30 degrees and about 60 degrees, or between about 20 degrees and about 70 degrees.

The second microlens structure124may include an optical lens that is configured to direct (e.g., collimate) the incoming light129that is transmitted along the first direction x1from the second angled surface125and exits at the sixth location122to be transmitted toward an environment (e.g., toward a receiver such as receiver168inFIG.4). For example, the second microlens structure124may include a spherical lens, a cylindrical lens, an elliptical lens, and the like. In some implementations, the second microlens structure124may be formed of a silicon material, a polymer plastic material, etc. In some implementations, the second microlens structure124may include an anti-reflective coating which is configured or formed to minimize reflection and increase light transmission through the second microlens structure124. The anti-reflective coating may include magnesium fluoride, silicon dioxide, dielectric coatings, and the like.

FIG.4depicts a block diagram of a LIDAR system150, according to some implementations of the disclosure. The semiconductor optical device100ofFIG.3can be included in the LIDAR system150ofFIG.4. The LIDAR system150can also include one or more of a light source152, a modulator154, one or more semiconductor optical amplifiers (SOAs)156, a first optical component158, the semiconductor optical device100, a second optical component166, and a receiver168.

The light source152can be configured to provide a light beam (e.g., a laser beam). The light source152can provide the light beam to the modulator154(e.g., a phase modulator). In some implementations, the light beam can be split among a plurality of channels (e.g., a plurality of transmit channels) that each carry a portion of the beam from the light source152. For instance, each transmit channel may correspond to a respective transmit output to provide a portion of the light beam to a respective portion of the environment of the LIDAR system150such that the LIDAR system150can scan multiple proximate points simultaneously. In some implementations, a local oscillator (LO) signal may also be output from the light source152(e.g., in a manner similar to that shown inFIG.5). The LO signal may be equivalent to the signal from the light source152or may be modulated from the signal from the light source152(e.g., by an LO modulator such as modulator204B ofFIG.5).

The modulator154can be configured to modulate the light beam output by the light source152to modify a phase and/or a frequency of the light beam. In some embodiments, the modulator154can be a silicon phase modulator. The modulator154can modulate the light beam by, for example, using Continuous Wave (CW) modulation or quasi-CW modulation. In some implementations, the modulator154can be disposed on a transmit die or another suitable substrate.

The LIDAR system150can include one or more amplifiers configured to receive the light beam from the light source152(e.g., via the modulator154) and amplify the light beam. The amplifiers may include, for example, the one or more semiconductor optical amplifiers (SOAs)156.

The first optical component158may be configured to receive the light beam emitted by the light source152(e.g., via the modulator154and the one or more SOAs156). The first optical component158may include a lens, for example a collimating lens or a micro lens array. In some implementations the first optical component158can include one or more optic components including an oscillatory scanner, a unidirectional scanner, a Risley prism, a circulator optic, and/or a beam collimator, etc.

The semiconductor optical device100may be configured to receive the light beam output by the first optical component158and transmit the light beam (e.g., the outgoing light119) to an environment of the LIDAR system150(e.g., to the object162). Aspects of the semiconductor optical device100have been described with respect toFIG.3, and therefore a detailed discussion of the operations and features of the semiconductor optical device100will be omitted for the sake of brevity. The semiconductor optical device100may be configured to receive the light beam reflected back from the object162in the environment and transmit the reflected light beam (e.g., the incoming light129) to the second optical component166.

The second optical component166may be configured to receive the reflected light beam (e.g., the incoming light129) from the environment (e.g., via the semiconductor optical device100). The second optical component166may include a lens, for example a collimating lens or a micro lens array. In some implementations the second optical component166can include one or more optic components including an oscillatory scanner, a unidirectional scanner, a Risley prism, a circulator optic, and/or a beam collimator, etc. The second optical component166may be configured to direct the reflected light beam (e.g., the incoming light129) toward the receiver168.

The receiver168may be configured to receive the reflected light beam (e.g., the incoming light129) from the environment (e.g., via the semiconductor optical device100and the second optical component166). In some implementations, the reflected light beam can be provided among a plurality of receive channels, where each receive channel captures a portion of transmitted light from a respective transmit channel (e.g., the outgoing light119) after being reflected by a corresponding point in the environment (e.g., the object162). In addition to the receive channels, the receiver168can include an LO channel configured to receive the LO signal output by the light source152.

FIG.5is a block diagram illustrating an example LIDAR sensor system for autonomous vehicles, according to some implementations. The environment includes a LIDAR system200that includes a transmit (Tx) path and a receive (Rx) path. The Tx path includes one or more Tx input/output ports (e.g., channels), and the Rx path includes one or more Rx input/output ports (e.g., channels). In some implementations, a semiconductor substrate and/or semiconductor package may include the Tx path and/or the Rx path. In some implementations, the semiconductor substrate and/or semiconductor package may include at least one of silicon photonics circuitry, programmable logic controller (PLC), or group III-V semiconductor circuitry.

In some implementations, a first semiconductor substrate and/or a first semiconductor package may include the Tx path and a second semiconductor substrate and/or a second semiconductor package may include the Rx path. In some arrangements, the Rx input/output ports and/or the Tx input/output ports may occur (or be formed/disposed/located/placed) along one or more edges of one or more semiconductor substrates and/or semiconductor packages, such as the semiconductor optical device100.

The LIDAR system200can be coupled to one or more sub-control system(s)201(e.g., the sub-control system(s)201ofFIG.6). In some implementations, the sub-control system(s)201may be coupled to the Rx path via the one or more Rx input/output ports. For instance, the sub-control system(s)201can receive LIDAR outputs from the LIDAR system200. The sub-control system(s)201can control a vehicle (e.g., an autonomous vehicle) based on the LIDAR outputs.

The Tx path may include a light source (e.g., laser source)202, a modulator204A, a modulator204B, an amplifier206, and one or more transmitters220. The Rx path may include one or more receivers222, a mixer208, a detector212, a transimpedance amplifier (TIA)214, and one or more analog-to-digital converters (ADCs)224. AlthoughFIG.2shows only a select number of components and only one input/output channel, the LIDAR system200may include any number of components and/or input/output channels (in any combination) that are interconnected in any arrangement to facilitate combining multiple functions of a LIDAR system, to support the operation of a vehicle.

The light source202may be configured to generate a light signal (or beam) that is derived from (or associated with) a local oscillator (LO) signal. In some implementations, the light signal may have an operating wavelength that is equal to or substantially equal to 1550 nanometers. In some implementations, the light signal may have an operating wavelength that is between 1400 nanometers and 1440 nanometers.

The light source202may be configured to provide the light signal to the modulator204A, which is configured to modulate a phase and/or a frequency of the light signal based on a first radio frequency (RF) signal (e.g., an “RF1” signal) to generate a modulated light signal, such as by Continuous Wave (CW) modulation or quasi-CW modulation. The modulator204A may be configured to send the modulated light signal to the amplifier206. The amplifier206may be configured to amplify the modulated light signal to generate an amplified light signal for transmission via the one or more transmitters220. The one or more transmitters220may include one or more optical waveguides or antennas. In some implementations, modulator204A and/or modulator204B may have a bandwidth between 400 megahertz (MHz) and 1000 (MHz).

The LIDAR system200includes one or more transmitters220and one or more receivers222. The transmitter(s)220and/or receiver(s)222can be included in a transceiver230. The transmitter(s)220can provide the transmit beam that it receives from the Tx path into an environment within a given field of view toward an object218. The one or more receivers222can receive a received beam reflected from the object218and provide the received beam to the mixer208of the Rx path. The one or more receivers222may include one or more optical waveguides or antennas. In some arrangements, the one or more transceivers230may include a monostatic transceiver or a bistatic transceiver.

The light source202may be configured to provide the LO signal to the modulator204B, which is configured to modulate a phase and/or a frequency of the LO signal based on a second RF signal (e.g., an “RF2” signal) to generate a modulated LO signal (e.g., using Continuous Wave (CW) modulation or quasi-CW modulation) and send the modulated LO signal to the mixer208of the Rx path. The mixer208may be configured to mix (e.g., combine, multiply, etc.) the modulated LO signal with the returned signal to generate a down-converted signal and send the down-converted signal to the detector212.

In some arrangements, the mixer208may be configured to send the modulated LO signal to the detector212. The detector212may be configured to generate an electrical signal based on the down-converted signal and send the electrical signal to the TIA214. In some arrangements, the detector212may be configured to generate an electrical signal based on the down-converted signal and the modulated signal. The TIA214may be configured to amplify the electrical signal and send the amplified electrical signal to the sub-control system(s)201via the one or more ADCs224. In some implementations, the TIA214may have a peak noise-equivalent power (NEP) that is less than 5 picowatts per square root Hertz (i.e., 5×10-12 Watts per square root Hertz). In some implementations, the TIA214may have a gain between 4 kiloohms and 25 kiloohms. In some implementations, detector212and/or TIA214may have a 3-decibel bandwidth between 80 kilohertz (kHz) and 450 megahertz (MHz).

The sub-control system(s)201may be configured to determine a distance to the object218and/or measure the velocity of the object218based on the one or more electrical signals that it receives from the TIA214via the one or more ADCs224.

FIG.6depicts a block diagram of an example autonomous vehicle control system300for an autonomous vehicle according to some implementations of the disclosure. The autonomous vehicle control system300can be implemented by a computing system of an autonomous vehicle. The autonomous vehicle control system300can include one or more sub-control systems201that operate to obtain inputs from sensor(s)302or other input devices of the autonomous vehicle control system300. In some implementations, the sub-control system(s)201can additionally obtain platform data308(e.g., map data310) from local or remote storage. The sub-control system(s)201can generate control outputs for controlling the autonomous vehicle (e.g., through platform control devices312, etc.) based on sensor data304, map data310, or other data. The sub-control system201may include different subsystems for performing various autonomy operations. The subsystems may include a localization system330, a perception system340, a planning system350, and a control system360. The localization system330can determine the location of the autonomous vehicle within its environment; the perception system340can detect, classify, and track objects and actors in the environment; the planning system350can determine a trajectory for the autonomous vehicle; and the control system360can translate the trajectory into vehicle controls for controlling the autonomous vehicle. The sub-control system(s)201can be implemented by one or more onboard computing system(s). The subsystems can include one or more processors and one or more memory devices. The one or more memory devices can store instructions executable by the one or more processors to cause the one or more processors to perform operations or functions associated with the subsystems. The computing resources of the sub-control system(s)201can be shared among its subsystems, or a subsystem can have a set of dedicated computing resources.

In some implementations, the autonomous vehicle control system300can be implemented for or by an autonomous vehicle (e.g., a ground-based autonomous vehicle). The autonomous vehicle control system300can perform various processing techniques on inputs (e.g., the sensor data304, the map data310) to perceive and understand the vehicle's surrounding environment and generate an appropriate set of control outputs to implement a vehicle motion plan (e.g., including one or more trajectories) for traversing the vehicle's surrounding environment. In some implementations, an autonomous vehicle implementing the autonomous vehicle control system300can drive, navigate, operate, etc. with minimal or no interaction from a human operator (e.g., driver, pilot, etc.).

In some implementations, the autonomous vehicle can be configured to operate in a plurality of operating modes. For instance, the autonomous vehicle can be configured to operate in a fully autonomous (e.g., self-driving, etc.) operating mode in which the autonomous platform is controllable without user input (e.g., can drive and navigate with no input from a human operator present in the autonomous vehicle or remote from the autonomous vehicle, etc.). The autonomous vehicle can operate in a semi-autonomous operating mode in which the autonomous vehicle can operate with some input from a human operator present in the autonomous vehicle (or a human operator that is remote from the autonomous platform). In some implementations, the autonomous vehicle can enter into a manual operating mode in which the autonomous vehicle is fully controllable by a human operator (e.g., human driver, etc.) and can be prohibited or disabled (e.g., temporary, permanently, etc.) from performing autonomous navigation (e.g., autonomous driving, etc.). The autonomous vehicle can be configured to operate in other modes such as, for example, park or sleep modes (e.g., for use between tasks such as waiting to provide a trip/service, recharging, etc.). In some implementations, the autonomous vehicle can implement vehicle operating assistance technology (e.g., collision mitigation system, power assist steering, etc.), for example, to help assist the human operator of the autonomous platform (e.g., while in a manual mode, etc.).

The autonomous vehicle control system300can be located onboard (e.g., on or within) an autonomous vehicle and can be configured to operate the autonomous vehicle in various environments. The environment may be a real-world environment or a simulated environment. In some implementations, one or more simulation computing devices can simulate one or more of: the sensors302, the sensor data304, communication interface(s)306, the platform data308, or the platform control devices312for simulating operation of the autonomous vehicle control system300.

In some implementations, the sub-control system(s)201can communicate with one or more networks or other systems with communication interface(s)306. The communication interface(s)306can include any suitable components for interfacing with one or more network(s), including, for example, transmitters, receivers, ports, controllers, antennas, or other suitable components that can help facilitate communication. In some implementations, the communication interface(s)306can include a plurality of components (e.g., antennas, transmitters, or receivers, etc.) that allow it to implement and utilize various communication techniques (e.g., multiple-input, multiple-output (MIMO) technology, etc.).

In some implementations, the sub-control system(s)201can use the communication interface(s)306to communicate with one or more computing devices that are remote from the autonomous vehicle over one or more network(s). For instance, in some examples, one or more inputs, data, or functionalities of the sub-control system(s)201can be supplemented or substituted by a remote system communicating over the communication interface(s)306. For instance, in some implementations, the map data310can be downloaded over a network to a remote system using the communication interface(s)306. In some examples, one or more of the localization system330, the perception system340, the planning system350, or the control system360can be updated, influenced, nudged, communicated with, etc. by a remote system for assistance, maintenance, situational response override, management, etc.

The sensor(s)302can be located onboard the autonomous platform. In some implementations, the sensor(s)302can include one or more types of sensor(s). For instance, one or more sensors can include image capturing device(s) (e.g., visible spectrum cameras, infrared cameras, etc.). Additionally or alternatively, the sensor(s)302can include one or more depth capturing device(s). For example, the sensor(s)302can include one or more LIDAR sensor(s) or Radio Detection and Ranging (RADAR) sensor(s). The sensor(s)302can be configured to generate point data descriptive of at least a portion of a three-hundred-and-sixty-degree view of the surrounding environment. The point data can be point cloud data (e.g., three-dimensional LIDAR point cloud data, RADAR point cloud data). In some implementations, one or more of the sensor(s)302for capturing depth information can be fixed to a rotational device in order to rotate the sensor(s)302about an axis. The sensor(s)302can be rotated about the axis while capturing data in interval sector packets descriptive of different portions of a three-hundred-and-sixty-degree view of a surrounding environment of the autonomous platform. In some implementations, one or more of the sensor(s)302for capturing depth information can be solid state.

The sensor(s)302can be configured to capture the sensor data104indicating or otherwise being associated with at least a portion of the environment of the autonomous vehicle. The sensor data304can include image data (e.g., 2D camera data, video data, etc.), RADAR data, LIDAR data (e.g., 3D point cloud data, etc.), audio data, or other types of data. In some implementations, the sub-control system(s)201can obtain input from additional types of sensors, such as inertial measurement units (IMUs), altimeters, inclinometers, odometry devices, location or positioning devices (e.g., GPS, compass), wheel encoders, or other types of sensors. In some implementations, the sub-control system(s)201can obtain sensor data304associated with particular component(s) or system(s) of the autonomous vehicle. This sensor data304can indicate, for example, wheel speed, component temperatures, steering angle, cargo or passenger status, etc. In some implementations, the sub-control system(s)201can obtain sensor data304associated with ambient conditions, such as environmental or weather conditions. In some implementations, the sensor data304can include multi-modal sensor data. The multi-modal sensor data can be obtained by at least two different types of sensor(s) (e.g., of the sensors302) and can indicate static and/or dynamic object(s) or actor(s) within an environment of the autonomous vehicle. The multi-modal sensor data can include at least two types of sensor data (e.g., camera and LIDAR data). In some implementations, the autonomous vehicle can utilize the sensor data304for sensors that are remote from (e.g., offboard) the autonomous vehicle. This can include for example, sensor data304captured by a different autonomous vehicle.

The sub-control system(s)201can obtain the map data310associated with an environment in which the autonomous vehicle was, is, or will be located. The map data310can provide information about an environment or a geographic area. For example, the map data310can provide information regarding the identity and location of different travel ways (e.g., roadways, etc.), travel way segments (e.g., road segments, etc.), buildings, or other items or objects (e.g., lampposts, crosswalks, curbs, etc.); the location and directions of boundaries or boundary markings (e.g., the location and direction of traffic lanes, parking lanes, turning lanes, bicycle lanes, other lanes, etc.); traffic control data (e.g., the location and instructions of signage, traffic lights, other traffic control devices, etc.); obstruction information (e.g., temporary or permanent blockages, etc.); event data (e.g., road closures/traffic rule alterations due to parades, concerts, sporting events, etc.); nominal vehicle path data (e.g., indicating an ideal vehicle path such as along the center of a certain lane, etc.); or any other map data that provides information that assists an autonomous vehicle in understanding its surrounding environment and its relationship thereto. In some implementations, the map data310can include high-definition map information. Additionally, or alternatively, the map data310can include sparse map data (e.g., lane graphs, etc.). In some implementations, the sensor data304can be fused with or used to update the map data310in real time.

The sub-control system(s)201can include the localization system330, which can provide an autonomous vehicle with an understanding of its location and orientation in an environment. In some examples, the localization system330can support one or more other subsystems of the sub-control system(s)201, such as by providing a unified local reference frame for performing, e.g., perception operations, planning operations, or control operations.

In some implementations, the localization system330can determine the current position of the autonomous vehicle. A current position can include a global position (e.g., respecting a georeferenced anchor, etc.) or relative position (e.g., respecting objects in the environment, etc.). The localization system330can generally include or interface with any device or circuitry for analyzing a position or change in position of an autonomous vehicle. For example, the localization system330can determine position by using one or more of: inertial sensors (e.g., inertial measurement unit(s), etc.), a satellite positioning system, radio receivers, networking devices (e.g., based on IP address, etc.), triangulation or proximity to network access points or other network components (e.g., cellular towers, Wi-Fi access points, etc.), or other suitable techniques. The position of the autonomous vehicle can be used by various subsystems of the sub-control system(s)201or provided to a remote computing system (e.g., using the communication interface(s)306).

In some implementations, the localization system330can register relative positions of elements of a surrounding environment of the autonomous vehicle with recorded positions in the map data310. For instance, the localization system330can process the sensor data304(e.g., LIDAR data, RADAR data, camera data, etc.) for aligning or otherwise registering to a map of the surrounding environment (e.g., from the map data310) to understand the autonomous vehicle's position within that environment. Accordingly, in some implementations, the autonomous vehicle can identify its position within the surrounding environment (e.g., across six axes, etc.) based on a search over the map data310. In some implementations, given an initial location, the localization system330can update the autonomous vehicle's location with incremental re-alignment based on recorded or estimated deviations from the initial location. In some implementations, a position can be registered directly within the map data310.

In some implementations, the map data310can include a large volume of data subdivided into geographic tiles, such that a desired region of a map stored in the map data310can be reconstructed from one or more tiles. For instance, a plurality of tiles selected from the map data310can be stitched together by the sub-control system201based on a position obtained by the localization system330(e.g., a number of files selected in the vicinity of the position).

In some implementations, the localization system330can determine positions (e.g., relative or absolute) of one or more attachments or accessories for an autonomous vehicle. For instance, an autonomous vehicle can be associated with a cargo platform, and the localization system330can provide positions of one or more points on the cargo platform. For example, a cargo platform can include a trailer or other device towed or otherwise attached to or manipulated by an autonomous vehicle, and the localization system330can provide for data describing the position (e.g., absolute, relative, etc.) of the autonomous vehicle as well as the cargo platform. Such information can be obtained by the other autonomy systems to help operate the autonomous vehicle.

The sub-control system(s)201can include the perception system340, which can allow an autonomous platform to detect, classify, and track objects and actors in its environment. Environmental features or objects perceived within an environment can be those within the field of view of the sensor(s)302or predicted to be occluded from the sensor(s)302. This can include object(s) not in motion or not predicted to move (static objects) or object(s) in motion or predicted to be in motion (dynamic objects/actors).

The perception system340can determine one or more states (e.g., current or past state(s), etc.) of one or more objects that are within the surrounding environment of an autonomous vehicle. For example, state(s) can describe (e.g., for a given time, time period, etc.) an estimate of an object's current or past location (also referred to as position); current or past speed/velocity; current or past acceleration; current or past heading; current or past orientation; size/footprint (e.g., as represented by a bounding shape, object highlighting, etc.); classification (e.g., pedestrian class vs. vehicle class vs. bicycle class, etc.); the uncertainties associated therewith; or other state information. In some implementations, the perception system340can determine the state(s) using one or more algorithms or machine-learned models configured to identify/classify objects based on inputs from the sensor(s)302. The perception system can use different modalities of the sensor data304to generate a representation of the environment to be processed by the one or more algorithms or machine-learned models. In some implementations, state(s) for one or more identified or unidentified objects can be maintained and updated over time as the autonomous vehicle continues to perceive or interact with the objects (e.g., maneuver with or around, yield to, etc.). In this manner, the perception system340can provide an understanding about a current state of an environment (e.g., including the objects therein, etc.) informed by a record of prior states of the environment (e.g., including movement histories for the objects therein). Such information can be helpful as the autonomous vehicle plans its motion through the environment.

The sub-control system(s)201can include the planning system350, which can be configured to determine how the autonomous platform is to interact with and move within its environment. The planning system350can determine one or more motion plans for an autonomous platform. A motion plan can include one or more trajectories (e.g., motion trajectories) that indicate a path for an autonomous vehicle to follow. A trajectory can be of a certain length or time range. The length or time range can be defined by the computational planning horizon of the planning system350. A motion trajectory can be defined by one or more waypoints (with associated coordinates). The waypoint(s) can be future location(s) for the autonomous platform. The motion plans can be continuously generated, updated, and considered by the planning system350.

The planning system350can determine a strategy for the autonomous platform. A strategy may be a set of discrete decisions (e.g., yield to actor, reverse yield to actor, merge, lane change) that the autonomous platform makes. The strategy may be selected from a plurality of potential strategies. The selected strategy may be a lowest cost strategy as determined by one or more cost functions. The cost functions may, for example, evaluate the probability of a collision with another actor or object.

The planning system350can determine a desired trajectory for executing a strategy. For instance, the planning system350can obtain one or more trajectories for executing one or more strategies. The planning system350can evaluate trajectories or strategies (e.g., with scores, costs, rewards, constraints, etc.) and rank them. For instance, the planning system350can use forecasting output(s) that indicate interactions (e.g., proximity, intersections, etc.) between trajectories for the autonomous platform and one or more objects to inform the evaluation of candidate trajectories or strategies for the autonomous platform. In some implementations, the planning system350can utilize static cost(s) to evaluate trajectories for the autonomous platform (e.g., “avoid lane boundaries,” “minimize jerk,” etc.). Additionally, or alternatively, the planning system350can utilize dynamic cost(s) to evaluate the trajectories or strategies for the autonomous platform based on forecasted outcomes for the current operational scenario (e.g., forecasted trajectories or strategies leading to interactions between actors, forecasted trajectories or strategies leading to interactions between actors and the autonomous platform, etc.). The planning system350can rank trajectories based on one or more static costs, one or more dynamic costs, or a combination thereof. The planning system350can select a motion plan (and a corresponding trajectory) based on a ranking of a plurality of candidate trajectories. In some implementations, the planning system350can select the highest ranked candidate, or a highest ranked feasible candidate.

The planning system350can then validate the selected trajectory against one or more constraints before the trajectory is executed by the autonomous platform.

To help with its motion planning decisions, the planning system350can be configured to perform a forecasting function. The planning system350can forecast future state(s) of the environment. This can include forecasting the future state(s) of other actors in the environment. In some implementations, the planning system350can forecast future state(s) based on current or past state(s) (e.g., as developed or maintained by the perception system340). In some implementations, future state(s) can be or include forecasted trajectories (e.g., positions over time) of the objects in the environment, such as other actors. In some implementations, one or more of the future state(s) can include one or more probabilities associated therewith (e.g., marginal probabilities, conditional probabilities). For example, the one or more probabilities can include one or more probabilities conditioned on the strategy or trajectory options available to the autonomous vehicle. Additionally, or alternatively, the probabilities can include probabilities conditioned on trajectory options available to one or more other actors.

To implement selected motion plan(s), the sub-control system(s)201can include a control system360(e.g., a vehicle control system). Generally, the control system360can provide an interface between the sub-control system(s)201and the platform control devices312for implementing the strategies and motion plan(s) generated by the planning system350. For instance, the control system360can implement the selected motion plan/trajectory to control the autonomous platform's motion through its environment by following the selected trajectory (e.g., the waypoints included therein). The control system360can, for example, translate a motion plan into instructions for the appropriate platform control devices312(e.g., acceleration control, brake control, steering control, etc.). By way of example, the control system360can translate a selected motion plan into instructions to adjust a steering component (e.g., a steering angle) by a certain number of degrees, apply a certain magnitude of braking force, increase/decrease speed, etc. In some implementations, the control system360can communicate with the platform control devices312through communication channels including, for example, one or more data buses (e.g., controller area network (CAN), etc.), onboard diagnostics connectors (e.g., OBD-II, etc.), or a combination of wired or wireless communication links. The platform control devices312can send or obtain data, messages, signals, etc. to or from the sub-control system(s)201(or vice versa) through the communication channel(s).

The sub-control system(s)201can receive, through communication interface(s)306, assistive signal(s) from remote assistance system370. Remote assistance system370can communicate with the sub-control system(s)201over a network. In some implementations, the sub-control system(s)201can initiate a communication session with the remote assistance system370. For example, the sub-control system(s)201can initiate a session based on or in response to a trigger. In some implementations, the trigger may be an alert, an error signal, a map feature, a request, a location, a traffic condition, a road condition, etc.

After initiating the session, the sub-control system(s)201can provide context data to the remote assistance system370. The context data may include sensor data304and state data of the autonomous vehicle. For example, the context data may include a live camera feed from a camera of the autonomous vehicle and the autonomous vehicle's current speed. An operator (e.g., human operator) of the remote assistance system370can use the context data to select assistive signals. The assistive signal(s) can provide values or adjustments for various operational parameters or characteristics for the sub-control system(s)201. For instance, the assistive signal(s) can include way points (e.g., a path around an obstacle, lane change, etc.), velocity or acceleration profiles (e.g., speed limits, etc.), relative motion instructions (e.g., convoy formation, etc.), operational characteristics (e.g., use of auxiliary systems, reduced energy processing modes, etc.), or other signals to assist the sub-control system(s)201.

The sub-control system(s)201can use the assistive signal(s) for input into one or more autonomy subsystems for performing autonomy functions. For instance, the planning system350can receive the assistive signal(s) as an input for generating a motion plan. For example, assistive signal(s) can include constraints for generating a motion plan. Additionally or alternatively, assistive signal(s) can include cost or reward adjustments for influencing motion planning by the planning system350. Additionally, or alternatively, assistive signal(s) can be considered by the sub-control system(s)201as suggestive inputs for consideration in addition to other received data (e.g., sensor inputs, etc.).

The sub-control system(s)201may be platform agnostic, and the control system360can provide control instructions to platform control devices312for a variety of different platforms for autonomous movement (e.g., a plurality of different autonomous platforms fitted with autonomous control systems). This can include a variety of different types of autonomous vehicles (e.g., sedans, vans, SUVs, trucks, electric vehicles, combustion power vehicles, etc.) from a variety of different manufacturers/developers that operate in various different environments and, in some implementations, perform one or more vehicle services.

FIG.7illustrates a flow diagram of an example, non-limiting method, according to one or more example embodiments of the disclosure.

The flow diagram ofFIG.7illustrates a method400for manufacturing a semiconductor optical device for a LIDAR sensor system for a vehicle, according to some implementations of the disclosure. Although shown in a particular sequence or order, unless otherwise specified, the order of the processes can be modified. Thus, the illustrated embodiments should be understood only as examples, and the illustrated processes can be performed in a different order, and some processes can be performed in parallel. Additionally, one or more processes can be omitted in various embodiments. Thus, not all processes are required in every embodiment. Other process flows are possible.

Referring toFIG.7, at operation410, the method400includes forming a plurality of microlens structures at respective first locations on a first major surface of respective first and second semiconductor wafers. For example, the plurality of microlens structures formed at operation410can correspond to microlens structures12depicted inFIGS.2C-2I. In the example ofFIGS.2H-2I, operation410can include forming a first plurality of microlens structures12aon a first major surface10aof first semiconductor wafer30aas well as forming a second plurality of microlens structures12bon a first major surface10bof second semiconductor wafer30b.

In some examples, forming a plurality of microlens structures at operation410includes employing a dry-etch process (e.g., reactive ion etching) to form the plurality of microlens structures at the respective first locations on the first major surface of the respective first and second semiconductor wafers. More particular exemplary operations associated with forming the plurality of microlens structures at operation410are depicted inFIG.8.

The flow diagram ofFIG.8illustrates more particular aspects of the operation410for forming a plurality of microlens structures on a semiconductor wafer, according to some implementations of the disclosure. Although shown in a particular sequence or order, unless otherwise specified, the order of the processes can be modified. Thus, the illustrated embodiments should be understood only as examples, and the illustrated processes can be performed in a different order, and some processes can be performed in parallel. Additionally, one or more processes can be omitted in various embodiments. Thus, not all processes are required in every embodiment. Other process flows are possible.

Referring toFIG.8, operation412may include forming a pattern on the first major surface of the respective first and second semiconductor wafers, the pattern defining the respective first locations. For example, the pattern formed at operation412may correspond to pattern14formed on the first major surface10of the respective first and second semiconductor wafers (e.g., first semiconductor wafer30aand second semiconductor wafer30b). The pattern14may define the respective first locations13at which the plurality of microlens structures are to be formed.

The pattern (e.g., pattern14) formed at operation412may be formed to define a plurality of generally circular or rounded openings corresponding to the respective first locations13. In some examples, a photolithography process may be employed at operation412to form the pattern14on the first major surface10of the respective first and second semiconductor wafers30aand30b. For example, a photosensitive material (e.g., a photoresist) may be applied to the first major surface10of the respective first and second semiconductor wafers30a,30b. A photomask formed to define the pattern14may then be placed over the photosensitive material. Light may be provided from a light source (e.g., an ultraviolet (UV) light source, deep UV light source, extreme UV light source, X-ray light source, etc.) When light is provided to the photomask, the photosensitive material is exposed in certain areas, causing the exposed areas to undergo a chemical change, making them either soluble or insoluble in a development solution. After development, the pattern14is transferred onto the first major surface10of the respective first and second semiconductor wafers30a,30bthrough one or more processes, such as etching, chemical vapor deposition, or an ion implantation process.

Referring still toFIG.8, operation414may include depositing respective portions of lens material at the respective first locations. For example, the respective portions of lens material deposited at operation414may correspond to portions of lens material15deposited at the respective first locations13defined by the pattern14depicted inFIGS.2B-2C. In some examples, lens material15deposited at operation414may include one or more of a polymer material, polypropylene, polystyrene, acrylic resin (PMMA), polycarbonate (PC), polyetherimide (PEI), cyclo-olefin polymer (COP), cyclo-olefin co-polymer (COC), methyl pentene, acrylonitrile butadiene styrene (ABS), ophthalmic material, glass material, thermoplastic material, or other suitable material. Lens material15may be deposited in generally cylindrical portions at the respective first locations13defined by the pattern14.

Referring still toFIG.8, operation416may include heating the respective portions of lens material to shape the lens material into the plurality of microlens structures. For example, heating at operation416can cause the lens material15to swell and transform into respective dome-shaped structures or hemispherical structures corresponding to the respective microlens structures12. After this, the wafer assembly ofFIG.2Bmay be subjected to a reactive-ion etching (RIE) process, such as a process that exposes the wafer assembly to a chemically reactive plasma in a wafer processing chamber to remove the pattern14. Plasma may be generated, for example, in the wafer processing chamber under low pressure by an electromagnetic field. High-energy ions from the plasma attack the first major surface10and react with it to remove pattern14.

Returning again toFIG.7, at operation420, the method400includes forming a plurality of notch structures at respective second locations on a second major surface of the respective first and second semiconductor wafers. The respective second locations on the second major surface are substantially opposite the respective first locations on the first major surface. For example, the plurality of notch structures formed at operation420can correspond to notch structures22depicted inFIGS.2E-2I. In the example ofFIGS.2H-2I, operation420can include forming a first plurality of notch structures22aon a second major surface11aof first semiconductor wafer30aas well as forming a second plurality of notch structures22bon a second major surface11bof second semiconductor wafer30b.

In some examples, forming a plurality of notch structures at operation420includes employing a wet-etch process (e.g., anisotropic silicon etching) to form the plurality of notch structures at the respective second locations on the second major surface of the respective first and second semiconductor wafers. More particular exemplary operations associated with forming the plurality of notch structures are depicted inFIG.9.

The flow diagram ofFIG.9illustrates more particular aspects of the operation420for forming a plurality of notch structures on a semiconductor wafer, according to some implementations of the disclosure. Although shown in a particular sequence or order, unless otherwise specified, the order of the processes can be modified. Thus, the illustrated embodiments should be understood only as examples, and the illustrated processes can be performed in a different order, and some processes can be performed in parallel. Additionally, one or more processes can be omitted in various embodiments. Thus, not all processes are required in every embodiment. Other process flows are possible.

Referring toFIG.9, operation422may include forming a pattern on a second major surface of the respective first and second semiconductor wafers, the pattern defining the respective second locations. For example, the pattern formed at operation422may correspond to pattern24formed on the second major surface11of the respective first and second semiconductor wafers (e.g., first semiconductor wafer30aand second semiconductor wafer30b). The pattern24may define the respective second locations20at which the plurality of notch structures22are to be formed. In some examples, a photolithography process may be employed at operation422to form the pattern24on the second major surface11of the respective first and second semiconductor wafers30a,30b. For example, a photosensitive material (e.g., a photoresist) may be applied to the second major surface11of the respective first and second semiconductor wafers30a,30b. A photomask formed to define the pattern24may then be placed over the photosensitive material. Light may be provided from a light source (e.g., an ultraviolet (UV) light source, deep UV light source, extreme UV light source, X-ray light source, etc.) When light is provided to the photomask, the photosensitive material is exposed in certain areas, causing the exposed areas to undergo a chemical change, making them either soluble or insoluble in a development solution. After development, the pattern24is transferred onto the second major surface11of the respective first and second semiconductor wafers30a,30bthrough one or more processes, such as etching, chemical vapor deposition, or an ion implantation process. In some embodiments, the pattern24is also formed along the entirety of the first major surface10including the microlens structures12to protect them during the wet-etch process of forming notch structures22at operation420.

Referring still toFIG.9, operation424may involve employing a wet-etch process to selectively remove material from the respective first and semiconductor wafers at exposed locations among the pattern formed on the second major surface. For example, the respective first and second semiconductor wafers30a,30bincluding pattern24may be exposed to an etching solution that selectively removes material from the respective first and second semiconductor wafers30a,30b. The semiconductor material removal at operation424may be implemented in planar directions, creating well-defined features with sharp corners and edges, such as the first angled surface26′ and second angled surface26″ of notch structures22. When semiconductor wafers30a,30brespectively include a silicon wafer, an anisotropic etching solution may be used such as a solution that contains one or more of: potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH), nitric acid and hydrofluoric acid (HNO3/HF), etc. An anisotropic etching solution may remove material from the (111) planes of the silicon wafer, creating features corresponding to the notch structure22.

Operation426may involve removing the pattern formed at operation422. For example, the pattern24may be removed from the respective first and second semiconductor wafers30a,30b, resulting in respective wafers as depicted inFIG.2F.

Referring again toFIG.7, at operation430, method400may include bonding the second major surface of the first semiconductor wafer to the second major surface of the second semiconductor wafer to form a semiconductor wafer pair. For example, bonding at operation430may correspond to bonding the second major surface11aof first semiconductor wafer30ato second major surface11bof second semiconductor wafer30bas depicted inFIG.2Hto form semiconductor wafer pair40. In some examples, bonding at operation430may include aligning a first notch structure of the first semiconductor wafer opposite a second notch structure of the second semiconductor wafer and adhering together portions of the second major surface forming the respective first and second semiconductor wafers. The alignment associated with bonding operation430may correspond to aligning the first notch structure22aof the first semiconductor wafer30aopposite the second notch structure22bof the second semiconductor wafer30bas depicted inFIG.2H.

At operation440, the method400may include dicing the semiconductor wafer pair to segment the semiconductor wafer pair into a plurality of individual semiconductor optical devices. For example, the dicing at operation440may correspond to dicing the semiconductor wafer pair40ofFIG.2H. For example, dicing at operation440may occur along dicing lines43as depicted inFIG.2Ito form a plurality of individual semiconductor optical devices44. The plurality of individual semiconductor optical devices44may respectively include at least one of the plurality of microlens structures12aand at least one of the plurality of notch structures22aformed on the first semiconductor wafer30aand at least one of the plurality of microlens structures12band at least one of the plurality of notch structures22bformed on the second semiconductor wafer30b. In some instances, dicing at operation440may include dicing the semiconductor wafer pair40at a vertex27aof the first notch structure22aand at a vertex27bof the second notch structure22b. The plurality of individual semiconductor optical devices formed by dicing at operation440may also correspond, for example, to the semiconductor optical device100depicted inFIGS.3-4.

FIG.10illustrates a flow diagram of an example, non-limiting method, according to one or more example embodiments of the disclosure.

The flow diagram ofFIG.10illustrates a method500for manufacturing a semiconductor optical device for a LIDAR sensor system for a vehicle, according to some implementations of the disclosure. Although shown in a particular sequence or order, unless otherwise specified, the order of the processes can be modified. Thus, the illustrated embodiments should be understood only as examples, and the illustrated processes can be performed in a different order, and some processes can be performed in parallel. Additionally, one or more processes can be omitted in various embodiments. Thus, not all processes are required in every embodiment. Other process flows are possible. The method500may be an extension of the method ofFIG.7. However, in some implementations the method500may be a standalone method or parts of method500may be selectively incorporated into the method400ofFIG.7.

Referring toFIG.10, at operation502, the method500includes cutting respective first and second semiconductor wafers from a semiconductor boule at a particular slicing angle such that the first major surface of the respective first and second semiconductor wafers is oriented in a range from about 5 to about 15 degrees relative to the (110) plane of the crystalline structure forming the semiconductor boule. For example, operation502may correspond to cutting respective first and second semiconductor wafers30a,30bsimilar to semiconductor wafer1depicted inFIGS.1A-1B. The respective first and second semiconductor wafers30a,30bmay be cut at operation502from a semiconductor boule2at a particular slicing angle5such that the first major surface10a,10bof the semiconductor wafers30a,30bare oriented in a range from about 5 to about 15 degrees relative to the (110) plane of the crystalline structure forming semiconductor boule2.

At operation504, the method500may include forming a plurality of microlens structures at respective first locations on a first major surface of respective first and second semiconductor wafers cut at operation502. For example, the plurality of microlens structures formed at operation504can correspond to microlens structures12depicted inFIGS.2C-2I. In the example ofFIGS.2H-2I, operation504can include forming a first plurality of microlens structures12aon a first major surface10aof first semiconductor wafer30aas well as forming a second plurality of microlens structures12bon a first major surface10bof second semiconductor wafer30b. In some examples, forming a plurality of microlens structures at operation504includes employing a dry-etch process (e.g., reactive ion etching) to form the plurality of microlens structures at the respective first locations on the first major surface of the respective first and second semiconductor wafers. Additional aspects of operation504may be similar to operation410ofFIGS.7-8, and so additional description is omitted here for the sake of brevity.

At operation506, the method500may include forming a plurality of notch structures at respective second locations on a second major surface of the respective first and second semiconductor wafers. The respective second locations on the second major surface are substantially opposite the respective first locations on the first major surface. For example, the plurality of notch structures formed at operation506can correspond to notch structures22depicted inFIGS.2E-2I. In the example ofFIGS.2H-2I, operation506can include forming a first plurality of notch structures22aon a first major surface10aof first semiconductor wafer30aas well as forming a second plurality of notch structures22bon a second major surface11bof second semiconductor wafer30b. In some examples, forming a plurality of notch structures at operation506includes employing a wet-etch process (e.g., anisotropic silicon etching) to form the plurality of notch structures at the respective second locations on the second major surface of the respective first and second semiconductor wafers. Additional aspects of operation506may be similar to operation420ofFIGS.7&9, and so additional description is omitted here for the sake of brevity.

At operation508, the method500may include applying an anti-reflective coating to the first major surface of the respective first and second semiconductor wafers including the plurality of microlens structures. For example, operation508may include applying the anti-reflective coating31to the first major surface10of the respective first and second semiconductor wafers30including the plurality of microlens structures12as depicted inFIG.2G.

At operation510, the method500may include applying a metal coating to the second major surface of the respective first and second semiconductor wafers including the plurality of notch structures. For example, operation510may include applying the metal coating32to the second major surface11of the respective first and second semiconductor wafers30including the plurality of notch structures22as depicted inFIG.2G. In some embodiments, an adhesive coating (e.g., silicon oxide, silicon nitride, a dielectric coating, etc.) is first applied to the second major surface11underneath the metal coating32(e.g., aluminum, chromium, anodized chromium or black chrome, etc.) to facilitate adhesion of the metal coating32to the silicon or other material forming semiconductor wafer30.

At operation512, the method500may include bonding the second major surface of the first semiconductor wafer to the second major surface of the second semiconductor wafer to form a semiconductor wafer pair. For example, bonding at operation512may correspond to bonding the second major surface11aof the first semiconductor wafer30ato the second major surface11bof the second semiconductor wafer30bas depicted inFIG.2Hto form the semiconductor wafer pair40. In some examples, bonding at operation512may include aligning a first notch structure of the first semiconductor wafer opposite a second notch structure of the second semiconductor wafer and adhering together portions of the second major surface forming the respective first and second semiconductor wafers. The alignment associated with bonding operation512may correspond to aligning the first notch structure22aof the first semiconductor wafer30aopposite the second notch structure22bof the second semiconductor wafer30bas depicted inFIG.2H.

At operation514, the method500may include dicing the semiconductor wafer pair to segment the semiconductor wafer pair into a plurality of individual semiconductor optical devices. For example, the dicing at operation514may correspond to dicing the semiconductor wafer pair40ofFIG.2H. For example, dicing at operation514may occur along dicing lines43as depicted inFIG.2Ito form a plurality of individual semiconductor optical devices44. The plurality of individual semiconductor optical devices44may respectively include at least one of the plurality of microlens structures12aand at least one of the plurality of notch structures22aformed on the first semiconductor wafer30aand at least one of the plurality of microlens structures12band at least one of the plurality of notch structures22bformed on the second semiconductor wafer30b. In some instances, dicing at operation514may include dicing the semiconductor wafer pair40at a vertex27aof the first notch structure22aand at a vertex27bof the second notch structure22b.

At operation516, the method500may include smoothing an outer surface of the plurality of semiconductor optical devices formed by dicing at operation514. In some examples, operation516includes smoothing the outer surface configured for transmitting and receiving beams of the LIDAR sensor system (e.g., first beam directing portion116and second beam directing portion126depicted inFIG.3). For example, an outer surface smoothed at operation516may correspond to the outer surface of the individual semiconductor optical devices44ofFIG.2Iwhere diced (e.g., at the dicing lines43). Smoothing at operation516may be implemented by one or more smoothing procedures, such as, but not limited, to grinding, polishing, lapping, etc. Smoothing of such surfaces can help to facilitate directing beams (e.g., transmitting and/or receiving beams) in and/or out of the semiconductor optical devices44.

At operation518, the method500may include applying an anti-reflective coating to the outer surface configured for transmitting and receiving beams of the LIDAR sensor system. For example, operation518includes applying an anti-reflective coating similar to anti-reflective coating31ofFIG.2Gto the outer surface configured for transmitting and receiving beams of the LIDAR sensor system (e.g., first beam directing portion116and second beam directing portion126depicted inFIG.3). For example, an anti-reflective coating may be applied at operation518to the outer surface smoothed at operation516.

The following describes the technology of this disclosure within the context of a LIDAR system and an autonomous vehicle for example purposes only. As described herein, the technology described herein is not limited to an autonomous vehicle and can be implemented for or within other systems, autonomous platforms, and other computing systems.