Homogenization of Radial Temperature by a Tungsten Sink in Sublimation Growth of 45 mm AlN Single Crystal

Abstract

To reduce the thermal stress during the sublimation growth of 45 mm AlN single crystal, a tungsten sink was put on the top of the crucible lid. Numerical experiments showed that the radial temperature gradient was reduced due to the homogenization effect on temperature as a result of the sink. Therefore, this simple tungsten sink method has the potential to grow large-size AlN ingots with fewer cracks. It also reveals that enhancing the heat exchange of the crucible lid is an effective way to improve the quality of crystal growth.

Optimization of the process parameters for the AlN crystal growth in the PVT method through an improved numerical simulation considering partial pressure of gas phases

“…For this reason, the radial temperature gradient must be minimized as much as possible. 18 To achieve this goal, designs A, B, and C are coupled to obtain designs D and E. As presented in Fig. 13, the combination of tungsten flakes and tungsten rings can significantly reduce the radial temperature gradient and growth rate difference of the crucible.…”

“…Consequently, numerical simulation tools have become indispensable for optimizing the process conditions of AlN single crystal growth. [17][18][19] Significant progress has already been made in the simulation of AlN crystal growth processes by the PVT method using finite element software-aided design. Segal and Karpov et al 20 proposed an earlier model considering gas diffusion, convective transport, and kinetic limitations of N adsorption/desorption on the AlN surface.…”

“…Consequently, numerical simulation tools have become indispensable for optimizing the process conditions of AlN single crystal growth. 17–19…”

Influence of Different Heater Structures on the Temperature Field of AlN Crystal Growth by Resistance Heating

“…In the simulation process, the insulation materials are the same, the assembly conditions are the same, and the crucible is set to a constant pressure of 50 kPa of high-purity nitrogen atmosphere. The material property parameters used in all the calculations can be referred to in the literature [ 13 , 17 , 19 ].…”

“…Y. Yu et al investigated the effect of adding a tungsten sink to the top of the AlN growth crucible on the temperature filed. This structure makes the radial temperature gradient on the growth cavity uniform [ 19 ].…”