FET technology

CNT based FETs can outperform the current FET technologies in many ways however, one of the most interesting properties of carbon nanotubes is the ballistic transport of electrons [178], which opens the possibility of constructing FETs that can operate at extremely high frequencies, making them suitable for the next generation electronic devices. Operation of SWCNT transistors has been demonstrated at microwave frequencies (see Fig. 21) [179] and more recently the operation of an SWCNT transistor in the terahertz frequency range was demonstrated [148]. 

For the measurement circuit, the amorphous silicon TFT has not been considered suitable for analog circuit or high frequency digital circuit, due to its low mobility and transconductance, while the poly-Si TFT has been developed into a large variety of analog circuits with moderate performance. The suitability of the three FET technologies for biosensor array applications is summarized in Table 6.1. 

Thus, it is clear that the gain of this amplifier is parameterized by the resistor values Ri and 1 2- This amplifier has the virtues of positive gain and very high input impedance (essentially that of tire op-amp), especially op-amps whose inputs are built with field-effect transistor (FET) technology. Such an amplifier is ideal for situations which require conditioning of output from sensors with high output impedance. The same process can be applied to the inverting amplifier ... 

The transistor as a component of the e-textile plays a crucial role in the textile electronic circuit. The existing fibrous transistors can be divided into two categories wire thin film transistors (WTFTs Lee and Subramanian, 2003 Maccioni et al., 2006 Locci et al., 2007) and wire electrochemical transistors (WECTs Hamedi et al., 2007 De Rossi, 2007 Tao et al., 2011). WTFT, also called WFET, is based on the field-effect transistor (FET) technology and WECT is based on electrochemical technology. With the help of these transistors, the textile electronic circuit can be achieved without loss of mechanical properties such as flexibility or softness. 

Tra.nsitorAmplifiers. Most gaUium-based field-effect transitor amplifiers (FETs) are manufactured using ion implantation (qv) (52), except for high microwave frequencies and low noise requirements where epitaxy is used. The majority of discrete high electron mobiHty transistor (HEMT) low noise amplifiers are currently produced on MBE substrates. Discrete high barrier transistor (HBT) power amplifiers use MOCVD and MBE technologies. 

The lower power dissipation associated with CMOS technology makes it attractive to crowd as many FETs as possible on a chip. The remarkable increase in the number of FETs per chip has been the result of shrinking FET sizes. If the gate length, E, and width, lU, are decreased by a factor of two. 

Integration of FETs into circuitry is one of the ultimate technology demonstrations, requiring many devices to be fabricated with near-uniform electrical characteristics. For the SAMFETs, the spontaneous nature of the assembly process renders it particularly attractive for low-cost, large-area electronics. The micron-scale channel a-substituted quinquethiophene SAMFETs were quickly implemented in different electronic circuits, with FETs having Si02 and SU8 gate dielectrics [70, 72]. 

Solid-state chemical sensors are fabricated by the same technology used for microelectronic chips. The field effect transistor (FET) is the heart of commercially available sensors such as the pH electrode in Figure 15-24. 

T.B. Ramachandran (Microwave Device Technology Corporation) notes that there are two inherent major disadvantages for current GaAs FET power devices ... 

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