Types Multigate device

several multigate models

dozens of multigate transistor variants may found in literature. in general, these variants may differentiated , classified in terms of architecture (planar vs. non-planar design) , number of channels/gates (2, 3, or 4).

planar double-gate transistor

the first international demonstration of multigate devices family using thin silicon film performed double-gate mosfet []. double-gate control of silicon-on-insulator (soi) transistors used force whole silicon film (interface layers , volume) in strong inversion (called “volume-inversion mosfet”) or strong accumulation (called “volume-accumulation mosfet”). original method of transistor operation, @ origin of unique electrostatic properties , scalability of multigate devices, offered excellent device performance, in particular, great increases in subthreshold slope, transconductance, , drain current. simulation program , experiments on simox structures used study new type of device.

planar double-gate transistors employ conventional planar (layer layer) manufacturing processes create double-gate devices, avoiding more stringent lithography requirements associated non-planar, vertical transistor structures. in planar double-gate transistors drain–source channel sandwiched between 2 independently fabricated gate/gate-oxide stacks. primary challenge in fabricating such structures achieving satisfactory self-alignment between upper , lower gates.

flexfet

flexfet planar, independently double-gated transistor damascene metal top gate mosfet , implanted jfet bottom gate self-aligned in gate trench. device highly scalable due sub-lithographic channel length; non-implanted ultra-shallow source , drain extensions; non-epi raised source , drain regions; , gate-last flow. flexfet true double-gate transistor in (1) both top , bottom gates provide transistor operation, , (2) operation of gates coupled such top gate operation affects bottom gate operation , vice versa. flexfet developed , manufactured american semiconductor, inc.