Design and optimization of complex single heater for vertical gradient freeze (VGF) grower

A complex single heater is designed for a VGF process to decrease process complexity caused by the use of a multi-heater system. To do this, a set of design criteria is selected to ensure that the final quality of the crystal is acceptable. Then a 3D transient finite element model is coupled with a new optimization procedure. All important physical phenome a such as temperature distribution, turbulent melt flow, thermal stress and crystal front shape are monitored and controlled during crystal growth. Using these, a single heater is designed for 4″ InP VGF crystal growth which meets all design criteria. It is concluded that using the complex single heater, high quality InP crystal growth by VGF process is possible.