Retrograde wells formation

Ion Implantation- these plasma machines are used to form the various parts of the coupled transistors at voltages of 5 kV to 2 MV. These include retrograde well formation, gates, drains and sources. 

Fig. 14.6. Application of ion implantations in advanced CMOS structure at several stages of the process, (a) Ion implants for retrograde well formation, punch-through-stop, and threshold voltage adjust (b) shallow source/drain (S/D) implant and (c) halo implant...

High energy implantation typically refers to doses in the 1011—1013 cm"2 at energies up to several MeV. The most common applications for which high energy implanters are used include retrograde and triple well formation, buried layer formation, and field isolation. 

Condensable Hquids also are recovered from high pressure gas reservoirs by retrograde condensation. In this process, the high pressure fluid from the reservoir produces a Hquid phase on isothermal expansion. As the pressure decreases isotherm ally the quantity of the Hquid phase increases to a maximum and then decreases to disappearance. In the production of natural gas Hquids from these high pressure wells, the well fluids are expanded to produce the optimum amount of Hquid. The Hquid phase then is separated from the gas for further processing. The gas phase is used as a raw material for one of the other recovery processes, as fuel, or is recompressed and returned to the formation. 

It predicts quite well vapor-liquid-phase equilibria for a multi-component system in the retrograde region but cannot predict the formation of a second liquid phase. 

The curve and the data points shown in figure 3A.2 are all dew points, incipient liquid formation. The experimental critical temperature for this mixture is -16.9°C. Therefore, the plot presents the large retrograde region for this mixture. From the PR calculations, the cricondentherm is estimated to be 29°C. In this mixture, liquid can form at a temperature almost 45 Celsius degrees higher than the critical temperature. The cricondenbar is estimated to be 12.5 MPa. It is difficult to confirm the location of either the cricondenbar or the cricondentherm with the available experimental data. However, the PR fits the data, and thus it can be concluded that the estimation of these points is quite accurate as well. 

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