Soitec FD-SOI substrates enable ultra-low-power features, unique cost/performance tradeoff, high-reliability and high-performance-mixed signal integration for a wide range of applications.

Fully Depleted Silicon-On-Insulator (FD-SOI) enables transistors to operate in fully depleted mode, which presents many advantages compared to partially depleted mode (Partially-Depleted SOI, PD-SOI) or bulk technologies.

To achieve this, FD-SOI wafers need to be both very thin and extremely uniform for the top and BOx layers.
Soitec guarantees the final SOI layer’s uniformity to within just a few atomic layers.
The BOx functions like a real second gate and allows chip makers to easily tune the threshold voltage of the transistors. 

The application level advantages of FD-SOI are:

Ultra low power

FD-SOI is a low-power technology that allows operating voltages as low as 0.4V for applications in which energy consumption per operation is minimum.

Digital performance

FD-SOI surpasses bulk technologies in terms of performance with more than 50% faster operation, 18% less power consumption, and the ability to achieve frequencies very close to FinFET devices.

Tunable power/performance point

Due to its thin BOX, FD-SOI benefits from extensive back biasing capability to easily tune the power/performance tradeoff depending on the application.
This allows designing to create a single platform for multiple use cases.

Mixed signal performance

FD-SOI allows unique analog performance thanks to its low variability characteristics, its body bias features, and its 2D device architecture, which present far less parasitic capacitances compared to 3D devices.


Studies show that FD-SOI provides better reliability than standard bulk process technologies with a 100x to 1000x improvement in soft error rates (SER).
This is especially significant to automotive and aerospace applications.

faster chips compared to bulk
SOI layer uniformity
higher cut off frequency improvement compared to FinFET
operating voltage
improvement in soft error rate
lower mask cost than FinFET

FD-SOI technology provides the best balance between digital performance, mixed-signal compatibility, power consumption and cost. 

Soitec produces FD-SOI wafers for following technology nodes: 65, 28, 22, 12nm.

Soitec FD-SOI wafers characteristics are:

  • Similar low-threshold defectivity levels compared to bulk substrates
  • 12nm to 15nm top silicon layer produced using Soitec’s Smart Cut technology
  • 15 to 25nm BOX layer
  • Atomistic uniformity control across the full length spectrum with dedicated metrology (from micro roughness to the wafer level)
  • Available in 300mm wafer