Silicon MOSFET

In Figure 5-la is shown a schematic representation of a silicon MOSFET (metal-oxide-semiconductor field effect transistor). The MOSFET is the basic component of silicon-CMOS (complimentary metal-oxide-semiconductor) circuits which, in turn, form the basis for logic circuits, such as those used in the CPU (central processing unit) of a modern personal computer [5]. It can be seen that the MOSFET is isolated from adjacent devices by a reverse-biased junction (p -channel stop) and a thick oxide layer. The gate, source and drain contact are electrically isolated from each other by a thin insulating oxide. A similar scheme is used for the isolation of the collector from both the base and the emitter in bipolar transistor devices [6],... 

Ordinarily interface-trap charge is negligible (< 10 °/cm in silicon MOSFETs) and the other nonideal effects on threshold voltage are accounted for by introducing the flatband voltage Vfb, which corrects the gate bias for these contributions. Then, using Eq. (7.8) with Fox = (Vth — — 4>r t)/d we find... 

A typical measurement of the Hall resistance % Uh/I and the resistivity p/ silicon MOSFET (Metal- xide- emiconductor... 

Figure 15 The Baliga pair power switch configuration utilizing a high-voltage SiC MESFET and a low-voltage silicon MOSFET.

Figure Bl.22.4. Differential IR absorption spectra from a metal-oxide silicon field-effect transistor (MOSFET) as a fiinction of gate voltage (or inversion layer density, n, which is the parameter reported in the figure). Clear peaks are seen in these spectra for the 0-1, 0-2 and 0-3 inter-electric-field subband transitions that develop for charge carriers when confined to a narrow (<100 A) region near the oxide-semiconductor interface. The inset shows a schematic representation of the attenuated total reflection (ATR) arrangement used in these experiments. These data provide an example of the use of ATR IR spectroscopy for the probing of electronic states in semiconductor surfaces [44]-...

MOSFETT s, and silicon oxide is deposited. The source/drain positions where electrical contact is to be made to the MOSFETs are defined, using the oxide-removal mask and an etch process. For shallow trench isolation, anisotropic silicon etch, thermal oxidation, oxide fill and chemical mechanical leveling are the processes employed. For shallow source/drains formation, ion implantation techniques are still be used. For raised source/drains (as shown in the above diagram) cobalt silicide is being used instead of Ti/TLN silicides. Cobalt metal is deposited and reacted by a rapid thermal treatment to form the silicide. Capacitors were made in 1997 from various oxides and nitrides. The use of tantalmn pentoxide in 1999 has proven superior. Platinum is used as the plate material. 

Field-effect transistors (FETs) Heterojunction bipolar transistors (HBTs) High electron mobility transistors (HEMTs) Metal oxide semiconductor FETs (MOSFETs) Single-electron transistors (SETs) Single-heterojunction HBTs (SH-HBTs) Thin-film transistors (TFTs) hydrogenated amorphous silicon in, 22 135... 

Deboy, G., et al., A New Generation of High Voltage MOSFETs Breaks the Limit Line of Silicon, lEDM 98 Technical Digest, December 6-9, 1998, pp. 683-685. 

Peters, D., et ah, 4H-SiC Power MOSFET Blocking 1200V with a Gate Technology Compatible with Industrial Applications, European Conference on Silicon Carbide and Related Materials, September 1-5, 2002. 

Casady, J. B., et al., Silicon Carbide Power MOSFET Technology, IEEE Inti. Symposium on Compound Semiconductors, September 8-11, 1997, pp. 359-362. 

One such device consists of two small islands of / -type semiconductor with and n-type silicon substrate. The islands are joined by a narrow / -type channel. The oxide portion of the MOSFET is an insulating layer of silicon dioxide that is formed by surface oxidation of the silicon. Gate, drain, and source connectors are attached. The MOSFET differs from the junction transistor in that a single type of charge carrier, either an electron or a hole, is utilized, instead of both. The conductivity of the channel... 

Perfection especially is required on the silicon surface. A 100 surface of silicon contains 6.8 x 1014 atoms/cm2. Surface defect densities must be less than one part in 105—105 defects/cm2 for satisfactory MOSFET operation. In fact, the discovery of the original point contact transistor was only possible because the native oxide on single-crystal germanium has surface defect densities less than one part in 104. Good silicon devices required the discovery (10) that the thermal oxidation of silicon could produce an excellent Si—Si02 interface. 

The excellence of a properly formed Si02—Si interface and the difficulty of passivating other semiconductor surfaces has been one of the most important factors in the development of the worldwide market for silicon-based semiconductors. MOSFETs are typically produced on (100) silicon surfaces. Fewer surface states appear at this Si—Si02 interface, which has the fewest broken bonds. A widely used model for the thermal oxidation of silicon has been developed (31). Nevertheless, despite many years of extensive research, the Si—Si02 interface is not yet fully understood. 

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