Medium current implantation

Medium current implantation typically refers to doses in the 1011—1014 cm"2 range at maximum energies of several hundred keV and as low as 3 keV. The most common applications for which medium current implanters are used include threshold voltage adjustment halo or pocket implants field isolation and channel engineering. 

A processing chamber in which only one wafer is implanted at a time is typically employed for medium current implanters. The endstation consists of a single scanning arm capable of linear motion of up to 140-200 mm s 1. over a range of up to 400 mm. The wafer is typically held on an electrostatic chuck which may be gas-cooled to maintain adequate wafer temperature. 

The various implants are typically serviced by distinct types of tools, each engineered to provide a solution for a specific segment of the implant application space. Traditionally, these segments have been called high current, medium current, and high energy, and can be characterized mainly by the dose and the energy of implanted ions. 

It should be noted that there is substantial applications overlap among the implantation segments. For example, medium current systems can run high dose source drain implants for pilot lines, albeit at low throughput. High energy... 

Ion implanter-both medium high current Furnaces-diffusion annealing oxidation... 

The main problems experienced when electrodes are in contact with, or implanted into, living cells (or tissues) are traumatization of the cells and the interaction of the biological medium with electrodes, both of which frequently impose significant uncertainties on the experimental data obtained, and should be kept to a minimum. The latter problem becomes less serious when the size of the electrode is made much smaller than the size of the cells or tissues, though some effects caused by the electrode may still remain. The recent development in microvoltammet-ric techniques, including fabrication of electrodes of / m dimensions [3, 4] and electronic devices to facilitate the measurement of very small currents, offers dramatic improvements in the quality of the data obtained in vivo. Furthermore, some experiments which were impossible to perform previously have recently become possible with the aid of these techniques. 

Two types of Li-AgVOj implantable batteries are available, namely a high-rate battery capable handling ampere-level current pulses, which is most ideal for cardioverter defibrillators, and a medium-rate battery operating in the milliampere range, which is best suited for atrial defibrillators. 

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