Transistor action

The immense importance of Si in transistor technology stems from the chance discovery of the effect in Ge at Bell Telephone Laboratories, New Jersey, in 1947, and the brilliant theoretical and practical development of the device by J. Bardeen, W. H. Brattain and W. Shockley for which they were awarded the 1956 Nobel Prize for Physics. A brief description of the physics and chemistry underlying transistor action in Si is given in the Panel (p. 332). 

A totally different way of looking at transistor action is by using a common-emitter circuit (Fig. 9.19B) Now the input current is (a relatively small) iBr and the output is the relatively large) collector current zc this collector current is still controlled by the Ebers-Moll equation, but the current gain is now explicit ... 

Consider a plane-parallel condenser of capacitance C whose plates are a p-type semiconductor (e.g., a CP) and a metal, and polarize the latter negatively. Excess positive charges (i.e., holes) appear at the surface of the semiconductor, and since its conductivity is low, they are in fact distributed over a certain thickness within the material. These excess holes, or at least part of them, should take part in the conduction. Applying a voltage to an external electrode not in contact with the semiconductor modulates its conductivity. This is the principle of the field effect, and clearly this control of the current through a gate electrode opens the possibility of transistor action without requiring the existence of p-n junctions. 

Whereas the Schottky barrier on undoped a-Si H is a useful configuration for experimental studies, the barrier on doped a-Si H may prove more important technologically. Because thin-film transistor action has been demonstrated, these devices may well form the basis of a new technology (Snell et al., 1981). An important aspect of this will be to form ohmic... 

Hagan, D. J., Wang, Z., Stegeman, G., Van Stryland, E. W., Sheik-Bahae, M., and Assanto, G., Phase-controlled transistor action by cascading of second-order nonlinearities in KTP, Opt. Lett., 19, 1305-1307 (1994). 

In situations where the performance is dependent on the uniqueness of the crystal structure of the material, such as the metal-Insulator transition in vanadium oxide, acousto-optic and acoustic-electric responses of AIN, ZnO, PZT, BaTiOg and SrTi03, superconducting properties of copper oxide based perovskites, A-15 silicides, and NbN, wide band gap and dopability of SiC, transistor action in Si/NiSi2(CoSi2)/Sl epitaxial layers etc., it is important to optimize the deposition conditions for the growth of a %[Pg.395]

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