Short-channel effects

The second short-channel effect is a drain field-dependent mobility, which occurs for source-drain fields above I05 V/cm, in agreement with similar phenom-... 

As already shown in the previous section, short channel effects such as lack of saturation can be avoided by a sufficiently thin gate insulator and improved charge injection could be realised by a thinner titanium adhesion layer. Never-... 

The short-channel effect is closely related to the lateral spreading of dopants from the source and drain areas to the gate region, which is contributed by two effects ... 

Figure 5.5.23 illustrates the electrical properties of a representative nanoscale laminated transistor (channel width of 20 [tm and channel length of 150 mn). The transistor exhibits a lower charge-carrier mobility and on/off current ratio compared to laminated micron-size transistors (channel width of 20 pm and channel lengths of 2.5 and 100 pm). Zaumseil and coworkers attributed the differences to contact resistances and short-channel effects [88]. Methods to lower contact resistance, which may include the clever use of monolayer chemistty and conductive polymers as electrodes, are being explored [87,88]. 

Fulfilling multilayer and miniature structures of memory devices led to the introduction of new materials and sfrucfures. For the structure, the design rule decreases less than 70 nm and the short channel effect (SCE) phenomenon appears to have a bad influence on fhe device drive if exisf-ing planar transistor (TR) is applied. To solve this problem, studies are in progress to apply recessed charmel array TR and three-dimensional structured FinFET in DRAM and floating gate, twin SONOS, and FinFET SONOS in flash memory (Eigure 6.3). 

In Fig. 2 are shown the I-V characteristics of a 12 pm channel length a-6T FET together with calculated characteristics using Eqs (3) and (4) and it can be observed that the agreement between data and the simulation is good. At such channel lengths, short-channel effects are negligible. 

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