US-20260128564-A1 - LIDAR Sensor System for Vehicles Including Integrated LIDAR Chip

Abstract

A LIDAR sensor system for a vehicle includes a silicon photonics substrate. The silicon photonics substrate includes: a semiconductor wafer; one or more surface features on a first surface of the semiconductor wafer; and a photoresist layer formed on the first surface of the semiconductor wafer, wherein the photoresist layer includes a laminated dry film. The silicon photonics substrate can be manufactured by obtaining a semiconductor wafer having one or more surface features; applying a dry film photoresist layer to a first surface of the semiconductor wafer; performing an adhesion bake process on the semiconductor wafer; developing the dry film photoresist layer to produce one or more developed regions in the dry film photoresist layer; and forming one or more solder bumps in the one or more developed regions.

Inventors

• James Ferrara
• Pruthvi Jujjavarapu
• Sen Lin
• Xue Liu
• Andrew Steil Michaels
• Parth Panchal
• ZhiZhong Tang

Assignees

• AURORA OPERATIONS, INC.

Dates

Publication Date

20260507

Application Date

20241118

Claims (20)

1. 1 . A method of manufacturing a semiconductor wafer for a LIDAR sensor system, the method comprising: obtaining a semiconductor wafer having one or more surface features on a first surface of the semiconductor wafer, the one or more surface features comprising one or more of a trench feature and an undercut feature, wherein the one or more surface features extend a depth of at least 50% of a thickness of the semiconductor wafer into the first surface of the semiconductor wafer; applying a dry film photoresist layer to the first surface of the semiconductor wafer; performing an adhesion bake process on the semiconductor wafer; and developing the dry film photoresist layer to produce one or more developed regions in the dry film photoresist layer.
2. 2 . The method of claim 1 , further comprising performing an under bump metallization (UBM) process on the first surface of the semiconductor wafer.
3. 3 . The method of claim 2 , wherein performing the UBM process on the first surface of the semiconductor wafer forms a UBM layer on the first surface of the semiconductor wafer.
4. 4 . The method of claim 1 , further comprising removing the dry film photoresist layer.
5. 5 . The method of claim 1 , wherein the adhesion bake process is performed such that the dry film photoresist layer is adhered to the first surface of the semiconductor wafer.
6. 6 . The method of claim 1 , wherein the adhesion bake process comprises heating the semiconductor wafer to an adhesion bake temperature, the adhesion bake temperature comprising a temperature between about 50 degrees Celsius and about 150 degrees Celsius.
7. 7 . The method of claim 1 , wherein developing the dry film photoresist layer comprises selectively exposing the dry film photoresist layer through a patterned mask.
8. 8 . The method of claim 1 , further comprising forming one or more solder bumps in the one or more developed regions, wherein the one or more solder bumps are configured to bond to a second substrate of the LIDAR sensor system in a flip chip configuration.
9. 9 . The method of claim 1 , wherein the semiconductor wafer further comprises a second surface opposite the first surface, wherein no signal contacts are disposed on the second surface.
10. 10 . The method of claim 1 , further comprising forming one or more waveguides on the first surface of the semiconductor wafer.
11. 11 . The method of claim 1 , wherein the semiconductor wafer comprises a silicon photonics wafer.
12. 12 . The method of claim 1 , wherein the dry film photoresist layer comprises a photoresist tape.
13. 13 . The method of claim 1 , further comprising incorporating the semiconductor wafer into a LIDAR sensor system.
14. 14 . The method of claim 13 , wherein incorporating the semiconductor wafer into the LIDAR sensor system comprises bonding the semiconductor wafer to a substrate of the LIDAR sensor system.
15. 15 . A system for manufacturing a semiconductor wafer for a LIDAR sensor system, the system operable to perform operations comprising: obtaining a semiconductor wafer having one or more surface features on a first surface of the semiconductor wafer, the one or more surface features comprising one or more of a trench feature and an undercut feature, wherein the one or more surface features extend a depth of at least 50% of a thickness of the semiconductor wafer into the first surface of the semiconductor wafer; applying a dry film photoresist layer to the first surface of the semiconductor wafer; performing an adhesion bake process on the semiconductor wafer; and developing the dry film photoresist layer to produce one or more developed regions in the dry film photoresist layer.
16. 16 . The system of claim 15 , wherein the adhesion bake process comprises heating the semiconductor wafer to an adhesion bake temperature, the adhesion bake temperature comprising a temperature between about 50 degrees Celsius and about 150 degrees Celsius.
17. 17 . The system of claim 15 , wherein developing the dry film photoresist layer comprises selectively exposing the dry film photoresist layer through a patterned mask.
18. 18 . The system of claim 15 , wherein the operations further comprise forming one or more waveguides on the first surface of the semiconductor wafer.
19. 19 . The system of claim 15 , wherein the dry film photoresist layer comprises a photoresist tape.
20. 20 . A LIDAR photonics substrate for a LIDAR sensor system for a vehicle, comprising: a semiconductor wafer; one or more surface features on a first surface of the semiconductor wafer, the one or more surface features comprising one or more of a trench feature and an undercut feature, wherein the one or more surface features extend a depth of at least 50% of a thickness of the semiconductor wafer into the first surface of the semiconductor wafer; and a photoresist layer formed on the first surface of the semiconductor wafer, wherein the photoresist layer includes a laminated dry film.

Description

PRIORITY CLAIM This application claims priority to and the benefit of U.S. patent application Ser. No. 18/511,387 (filed Nov. 16, 2023), which is incorporated herein by reference in its entirety. BACKGROUND Light Detection and Ranging (LIDAR) systems use lasers to create three-dimensional representations of surrounding environments. A LIDAR system includes at least one emitter paired with a receiver to form a channel, though an array of channels may be used to expand the field of view of the LIDAR system. During operation, each channel emits a laser beam into the environment. The laser beam reflects off of an object within the surrounding environment, and the reflected laser beam is detected by the receiver. A single channel provides a single point of ranging information. Collectively, channels are combined to create a point cloud that corresponds to a three-dimensional representation of the surrounding environment. SUMMARY Aspects and advantages of implementations of the present disclosure will be set forth in part in the following description, or may be learned from the description, or may be learned through practice of the implementations. Example aspects of the present disclosure are directed to LIDAR systems. As further described herein, the LIDAR systems can be used by various devices and platforms (e.g., robotic platforms, etc.) to improve the ability of the devices and platforms to perceive their environment and perform functions in response thereto (e.g., autonomously navigating through the environment). The present disclosure is directed to LIDAR systems for use with, for example, vehicles. A LIDAR system according to example aspects of the present disclosure includes a LIDAR module that includes an emitter configured to emit a light beam. The LIDAR module includes an optic device configured to split the light beam into a plurality of light beams. The LIDAR module includes an optical amplifier array configured to amplify the plurality of light beams to generate a plurality of amplified light beams. For instance, the optical power of the amplified light beams can, in some implementations, range from 10 decibels greater than an optical power of the plurality of light beams to 30 decibels greater than the optical power of the plurality of light beams. The LIDAR module includes a transceiver configured to facilitate transmitting the plurality of amplified light beams into a surrounding environment. The transceiver is further configured to receive return light beams from the surrounding environment that can be combined to generate point cloud data representative of objects in the surrounding environment. An integrated LIDAR system typically consists of complex circuits of photonic elements. LIDAR system electronics, such as silicon photonics dies, can be bonded to other components of the LIDAR system, such as a packaging substrate, using “flip chip” bonding. As opposed to techniques such as wire bonding, where one or more conducting wires are attached between signal contacts on one or more dies, in a flip chip configuration all of the signal contacts between a die and a substrate (or a first die and a second die) are respectively located on a single surface of each component. The surfaces of the die or the substrate having the signal contacts include one or more flip chip bumps. When the surfaces of the die and the substrate having the signal contacts are mated, typically under pressure, heat, or some other bonding force, the flip chip bumps can form one or more flip chip bump bonds between the die and the substrate to couple the die to the substrate. Flip chip bonding can provide improved form factor, electronics density, performance and/or operational parameters as well as reduced cost compared to some other solutions such as wire bonding. One existing approach to flip chip bonding, especially for common semiconductor integrated circuit wafers, is to perform under bump metallization (UBM) deposition on the entire surface of the wafer, followed by coating the surface with a liquid photoresist. The surface is then exposed to a bake process and a mask-selective photoresist exposure and development process. The developed area is then plated with solder. Once the plating is finished, the photoresist is stripped, and the UBM is etched away. However, wafers having nonuniform or irregular surfaces can suffer defects with this approach. For instance, many LIDAR system electronics, such as silicon photonics wafers or dies used for manufacturing silicon photonics chips, may have one or more features on the surface that is flip chip bonded. The features can be, for example, etch features that are etched into the surface that is flip chip bonded. For instance, the wafer may have one or more trench features etched in the surface that is flip chip bonded. The trench features can be used, for example, for optical butt-coupling purposes. As another example, the features can be or can include one or more undercut feat