American Semiconductor, Inc. 200mm CMOS Foundry


A Better Kind of CMOS

Flexfet TEM Image

Flexfet is an advanced CMOS process characterized by an Independently Double Gated transistor. The novel design of the Flexfet transistor brings many benefits not realized in standard CMOS processes.

Flexfet provides Dynamic Threshold Control (DTC), enabling Vt to be controlled on-the-fly while the IC is in operation. With DTC, designers are not locked into choosing a Vt process corner. DTC allows the same IC to be optimized for speed and power, adjusted as the system operation requires.

Flexfet delivers Ultra Low Power (ULP) operation, running at as little as 0.5V, fully depleted, at speeds that is orders of magnitude faster than sub-threshold approaches to low power. Flexfet ULP enables systems to maximize power savings without sacraficing speed.

Flexfet is inherently radiation tolerant. The unique independently double gated design and SOI processing of Flexfet delivers a process that is both SEE and TID hard, making Flexfet extremely useful in avionics and space systems.

Flexfet enables integrated sensors such as photodiodes to be built on the same die as the CMOS, delivering monolithic detectors. In the example of photodetectors, the photodiode is fabricated in the handle silicon and the ROIC CMOS is fabricated on the SOI layer. This delivers a Monolithic Active Pixel Sensor (MAPS) for backside illuminated sensors.

Flexfet is a gate-last process, which enables integration of novel materials with low thermal budgets.

Flexfet is commercially available as a foundry process from American Semiconductor with standard Process Development Kits available for 180nm and 130nm nodes, and the Radiation Effects Process Development Kit (RE-PDK) developed with support from Air Force Research Labs SHARE program.

Flexfet Advantages

  • Ultra Low Power

  • Dynamic Threshold Control

  • Inherent Radiation Tolerance

  • Maximizes Speed and Power

  • Ideal for RF, Analog, Wireless, Low Power, Military, and Aerospace Applications

Flexfet Features

  • Independent Double-Gated (IDG) CMOS Transistor

  • Metal Top-Gated Fully Depleted MOSFET

  • Self Aligned JFET Bottom Gate

  • SOI (Silicon-On-Insulator) Wafer Fabrication

  • Flexfet Options: Detector, MIMCAP, Thick Ox

Flexfet ULP was developed with support from Air Force Research Labs. The video below is a demonstration of Flexfet Ultra Low Power operation.

Flexfet Diagram

Flexfet Image
Flexfet Status
Flexfet is Advanced CMOS Technology that enables cutting edge designs


Imagers / Detectors


Analog / Mixed Signal