Tri Gate Transistors

Tri-Gate transistors, the first to be truly three-dimensional, mark a major revolution in the Semiconductor industry. The semiconductor industry continues to push technological innovation to keep pace with Moore’s Law, shrinking transistors so that ever more can be packed on a chip. However, at future technology nodes, the ability to shrink transistors becomes more and more problematic, in part due to worsening short channel effects and an increase in parasitic leakages with scaling of the gate-length dimension. In this regard Tri-gate transistor architecture makes it possible to continue Moore's law at 22nm and below without a major transistor redesign. The physics, technology and the advantages of the device is briefly discussed in this paper. Since their inception in the late 1950s, planar transistors have acted as the basic building block of microprocessors. The scaling of planar transistors requires the scaling of gate oxides and source/drain junctions. However, as these transistor elements become harder to scale, so does the transistor gate length. The scaling of planar transistors is getting more difficult due to the worsening electrostatics and short-channel performance with reducing gate-length dimension. In a multigate device, the channel is surrounded by several gates on multiple surfaces, allowing more effective suppression of "off-state" leakage current. Multiple gates also allow enhanced current in the "on" state, also known as drive current. These advantages translate to lower power consumption and enhanced device performance. Non-planar devices are also more compact than conventional planar transistors, enabling higher transistor density which translates to smaller overall microelectronics state, also known as drive current. These advantages translate to lower power consumption and enhanced device performance. Non-planar devices are also more compact than conventional planar transistors, enabling higher transistor density which translates to smaller overall microelectronics A new transistor architecture that can significantly improve the electrostatics and short-channel performance is the tri-gate transistor, as shown in Figure 1. This transistor, which can be fabricated either on the SOI substrate or standard bulk-silicon substrate, has a gate electrode on the top and two gate electrodes on the sides of the silicon body. The top-gate transistor has physical gate length LG and physical gate width WSi, while the side-gate transistor has physical gate length LG and physical gate width HSi,