Patent ID: 7135073

Claim:
A method of producing nitrogenous semiconductor crystal materials of the form A X B Y C Z N V M W in the nature of strata on a wafer, wherein A, B and C represent elements of elemental group II or group III, N represents nitrogen, M represents an element of elemental group V or group VI, and X, Y, Z, V and W represent the mol fraction of each element in A X B Y C Z N V M W , in a reactor comprising a reaction chamber defined by a set of chamber walls and an upper side and lower side thereof, a first wafer support positioned within the reaction chamber, a gas inlet through which process gases flow into the reaction chamber, a gas mixing system in fluid communication with the reaction chamber, a gas outlet through which the process gases are discharged from the reaction chamber, a second wafer support positioned on the first wafer support, a heating system for heating the first wafer support, and a controller for controlling the process gases and the reaction chamber; the method comprising: growing a plurality of layers on each other, wherein the composition of the layers differ from each other due to a different composition of the gaseous phase and different growth temperatures inside the reaction chamber; wherein a plurality of temperatures selected from the group consisting of the temperature of the gas inlet, T 1 , the temperature of the chamber walls, T 2 , the temperature of the first wafer support, T 3 , the temperature of the second wafer support, T 4 , the temperature of the gas outlet, T 5 , the temperature of the gas mixing system, T 6 , the temperature of the upper side of the reaction chamber, T 7 , and the temperature of the heating system, T 8 are adjusted by a temperature management system; wherein the temperature management system uses temperature variation profiles to control the plurality of temperatures and a temporal variation of at least one of the plurality of temperatures; wherein the temperature variation profiles have been determined on the basis of numeric simulation; and controlling the temperatures of the gas outlet, T 5 , the second wafer support T 4 , and the first wafer support, T 3 such that the gas outlet, T 5 is less than the temperature of the second wafer support, T 4 , and the temperature of the second wafer support, T 4 , is less than the temperature of the first wafer support, T 3 ; wherein the temperature adjustment is achieved by active heating, thermal radiation, and cooling.