The Field Effect Transistor

Abstract

Previous work on field‐effect transistors considered the performance of the device when operated with electric fields in the channel below the critical field, Ec, where the mobility of carriers becomes dependent on field. This work is reviewed and it is shown that, in this range of operation, the frequency cut‐off, f, and transconductance, gm, of the device increase with increasing values of electric field. New theory is derived for the performance with electric fields greater than Ec, where the mobility is proportional to E−1/2. It is shown that, although both f and gm continue to increase with electric field in this range, the corresponding increase in the power dissipated is so rapid that such designs are unattractive. It is concluded that a good compromise is to operate with the average channel field equal to Ec. The performance in this particular case is considered in detail and the results summarized in a design nomograph. It is found that f is inversely proportional to the “pinch‐off” voltage. The pinch‐off voltage cannot, however, be made indefinitely small because the gate junction must be in the saturated condition. A reasonable estimate of the minimum voltage is 1/2 volt and this leads to a maximum value of f of 1,000 mc/s. A description is given of the fabrication and performance of several field‐effect transistors operating in both the constant and non‐constant mobility ranges. It is shown that the performance of these units is in agreement with theory. One of these units had a frequency cut‐off of 50 mc/s with a transconductance of 1.6 ma/v when operated at 40 volts and 40 ma.

Critical current modulation induced by an electric field in superconducting tungsten-carbon nanowires

“…This electric field-induced resistivity control is at the core of the operation of field-effect transistors (FETs). FETs are employed as active electronic components that exploit the field effect for electrical signal switching and amplification 2 . Particularly, metal oxide semiconductor FETs (MOSFETs) fabricated on integrated circuits represent the most extensively used building block in that industry for the fabrication of a wide range of electronic-based devices thanks to their simplicity and affordability 3 .…”

Recent Progress on Conductive Metal‐Organic Framework Films

“…The field effect transistor (FET) is a three terminal semiconductor device that plays an important role in modern electronic applications due to its high integration, mass production and adjustable electrical performance. [134][135][136] However, conductive MOF materials with high crystallinity, microporous structures, and low dielectric constants provide a new candidate material for the modified FET dielectric layer. [137][138][139] In 2017, Zhang et al First prepared the FETs based on a thin film of the SURMOF HKUST-1, using LPE.…”

High-frequency response and thermal effects in GaN diodes and transistors: modeling and experimental characterization

“…The dierent models of SSECs in HEMTs and the methods to obtain the elements of the circuit can be found in [144,145]. In this section, the technique we use to extract the parameters of the equivalent circuit is described.…”

“…Once the eect of the pads (extrinsic parameters) has been characterized and it is possible to remove it from the measurements, in this subsection, we extract the Small-Signal Equivalent Circuit (SSEC) of the HEMTs. A rst model of an equivalent circuit is proposed in [144]. However, the most accepted is the one reported in [146].…”

“…On the other hand, in connection with modeling, MC simulations are a very appropriate tool to study the AC behavior of the devices by means of the procedure explained in subsection 1.3.2. The equivalent circuits have been used by researchers since the rst models were proposed[144,145], to understand the physics of the devices, compare the performance between dierent technologies and model the device behavior in electronic design programs. Apart from applications like amplication, based on the linear behavior of the devices modeled by means of the SSEC, other applications exploiting the nonlinearities present in their response are also quite relevant, like RF signal detection, as reported in section 2.3 of chapter 2 for the case of SSDs.…”