Sony Patents a Two-Layer Stacked Chip for Compact LiDAR Distance Sensing

By Patentlyze Team · Updated May 22, 2026

Sony Semiconductor is trying to shrink a LiDAR sensor down to a two-layer silicon sandwich — putting the laser emitter and light receiver on one chip, and the processing circuitry on a second chip bonded directly beneath it.

What Sony's stacked LiDAR sensor chip actually does

Imagine your phone trying to measure how far away your face is to unlock itself, or a robot trying to judge the distance to an obstacle. That kind of depth-sensing usually requires a device that shoots out pulses of light, waits for them to bounce back, and times how long the round trip takes. The problem is that doing all of that — emitting, receiving, and processing — traditionally needs separate components, which takes up space and drains power.

Sony's patent describes a sensor that squeezes all of this onto two stacked chips bonded together. The top chip, made of a Group-IV material (think silicon or germanium — the basic semiconductors your processor is built from), holds both the laser emitter and the light receiver side by side. The bottom chip handles the electronic readout — turning the raw light signal into a distance number.

By stacking these layers instead of spreading them across a circuit board, you get a smaller footprint, fewer connections that can fail, and — according to the filing — lower power consumption. It's the same philosophy behind stacked memory chips, just applied to depth sensing.

How the two-substrate stack splits light and logic

This patent covers a time-of-flight (ToF) distance-measuring device built as a two-substrate stack. ToF works by sending out a short pulse of light and measuring how long it takes to return after bouncing off an object — the longer the round trip, the farther away the object is.

The key architectural choice here is monolithic integration on a Group-IV substrate. Group-IV materials (silicon, germanium, silicon-germanium alloys) are the workhorses of conventional chip fabrication. By building both the light-emitting portion (the laser or LED that fires pulses) and the light-receiving portion (the photodetector that catches the reflected signal) on the same piece of Group-IV material, Sony avoids the hybrid assembly that typically involves bonding a compound semiconductor laser (like InGaAs or GaAs) onto a silicon base — a step that adds cost and complexity.

The second substrate is laminated directly onto the first and carries the readout circuit — the analog-to-digital conversion and timing logic that interprets the photodetector's signal as a distance value.

• First substrate (Group-IV): integrates light emitter + light receiver together
• Second substrate: stacked below, handles electronic readout and signal processing
• Result: smaller package, fewer off-chip connections, lower power draw

What this means for small, low-power depth cameras

Miniaturization is the central pressure in depth-sensing right now. Automotive LiDAR, AR/VR headsets, industrial robots, and even consumer smartphones all want accurate distance measurement in an ever-shrinking form factor. Today's solutions often involve hybrid assemblies — a laser chip from one vendor, a detector from another, glued or wire-bonded together. That approach has real limits in size, yield, and cost.

Sony Semiconductor is one of the world's largest image sensor manufacturers, and this filing signals a push to own more of the depth-sensing stack in silicon. If they can bring Group-IV-based emitters up to production quality, the stacked architecture here would let them build a full ToF sensor the same way they already build stacked CMOS image sensors — with well-understood fab processes and tight vertical integration. That's a meaningful cost and supply-chain advantage.

Editorial commentary on a publicly published patent application. Not legal advice.