Yole about iPad Pro SPAD LiDAR: Sony Landed on the Moon Without Us Knowing

Yole Developpement publishes an article "With the Apple iPad LiDAR chip, Sony landed on the moon without us knowing" by its Principal Analyst Pierre Cambou and Taha Ayari, Technology & Cost Analyst at System Plus Consulting.

"...once we studied the cross-section an all-new story unfolded. In front of us lies the first ever consumer CMOS Image Sensor (CIS) product with in-pixel connection – and, yes, it is a single photon avalanche diode (SPAD) array. There was a space race for this new generation of 3D sensing chip, but so far, everyone thought that the winner would be for ST Microelectronics, Yole Développement included.

ST Microelectronics seemed to have the lead in this domain, as it was already shipping millions of SPAD detectors. This was until Sony’s technology dominance entered the race. In three years’ time Sony’s process engineers realized what many thought impossible in other places. They brought to reality a product that will probably have long lasting consequences in the consumer world but also in industrial robotics, automotive, in short all sensing markets.

A year ago, when Sony renamed its semiconductor division “Imaging & Sensing”, the sensing part was limited to Industrial Machine Vision image sensors, which remained a high-end niche market. Then it made two separate moves. The first was the supply of iToF sensors to Huawei and Samsung, generating in the order of $300M in 2019. The second was this design win of dToF sensors for Apple iPads, which could eventually end up in iPhones. Sony’s sensing revenues will probably exceed $1B in 2020 out of a business just surpassing the $10B landmark. This successful transition from imaging to sensing has been instrumental to Sony’s continuous strength in the CIS market. It will be a building block for the prosperous future of the division.

In term of technology innovation, the LiDAR module of the new iPad Pro is as packed as the Apollo program’s pioneering Eagle lander. In a small footprint it is a complex optical module, holding the sensor, a Vertical Cavity Surface Emitting Laser (VCSEL) and a VCSEL driver.

The Sony’s 30K resolution, 10µm pixel size sensor is indeed using dToF technology with a SPAD array. The in-pixel connection is realized between the CIS and the logic wafer with hybrid bonding Direct Bonding Interconnect technology, which is the first time Sony is using 3D stacking for its ToF sensors. Deep trench isolation, trenches filled with metal, completely isolate the pixels."