OPTIMIZATION OF ,PARAMETERS IN TEMPERATURE EFFECTS INCORPORATED MODEL OF LPE GROWTH OF GaAs

Abstract

Liquid phase epitaxy is the most widely used technique today in growing epitaxial layers of GaAs.The x.Z,athem8LtjC,- , I. models put forward so far, of LPE process, consider quantities like diffusivity of As in Gallium and heat of mixing of solution as independent of operating temperature. Attempt has been made in the present work to develop a more accurate model which considers the varia-tion of these quantitates with temperature. There are five growth parameters which affect the LPE growth viz, equilibrium temperature, contact tempera-ture, time duration over which growth takes place, cooling rate and thickness of the solution, Variation of epilayer thickness grown with growth duration for different sets of these parameters in a restricted practicable range is calculated and plotted. Two particular cases of growth, one taking temperature effects variation into consideration, and another ignoring it, are compared and it is observed that for the sake of accuracy, incorporation of temperature effects is necessary. Variation of instantaneous growth rate with time is calculated for different sets of parameters and it is found that under some conditions, the LPE growth can be simulated by a simple expression.