FDSOI Technology

Fully-depleted silicon-on-insulator

FD-SOI, is an innovative technology that holds the established planar process while ensuring a continuation of the efficiency improvements projected by Moore’s law.

FD-SOI delivers

• The die size reductions, 
• Power reductions, 
• Increases in performance and 
• Increased functionality projected by Moore’s Law without the need to introduce dramatically more complex manufacturing processes. 

Two key innovations are combined, synergistically, to create the FD-SOI process.

• The first is the use of an ultra thin oxide insulator placed on the top of the base silicon. 
• Second, a very thin silicon layer creates the transistor channel. Due to the thinness of this layer, no channel doping is required, making the transistor fully depleted. 

The resulting FD-SOI structure is an evolution from the familiar bulk CMOS process, as shown in the illustration in Figure

Advantages of FD-SOI Technology 

The FD-SOI structure results in much better transistor characteristics compared to traditional bulk CMOS technology. As illustrated in Figure , the FD-SOI buried oxide layer reduces the parasitic capacitance between the source and drain exhibited by bulk technology. The buried oxide layer also constrains electrons flowing between the source and drain to significantly reduce performance- and power-degrading leakage currents. The fully depleted channel also reduces leakage.

Reference:
FDSOI_globalfoundary