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

Based on the actual hot zone structure of an AlN crystal growth resistance furnace, the global numerical simulation on the heat transfer process in the AlN crystal growth was performed. The influence of different heater structures on the growth of AlN crystals was investigated. It was found that the top heater can effectively reduce the axial temperature gradient, and the side heater 2 has a similar effect on the axial gradient, but the effect feedback is slightly weaker. The axial temperature gradient tends to increase when the bottom heater is added to the furnace, and the adjustable range of the axial temperature gradient of the side 1 heater + bottom heater mode is the largest. Our work will provide important reference values for AlN crystal growth by the resistance method.

Gas Flow Engineering in Rapid Thermal Processing

ABSTRACTGas flow engineering involves gas dynamics optimization for effective ambient change before heating and for homogeneous convective cooling of the wafers during the heating steps. Multiple gas buffle system, dynamical gas handling, low pressure operation, low temperature edge guard ring and independent top and bottom heater bank control are the proper tools for this optimization. Silicon surface or interface damage during inert gas anneal can be avoided by addition of a small amount of oxygen.

Effects of Size of Simulated Microelectronic Chips on Boiling and Critical Heat Flux

Microelectronic chips were simulated with thin foil heaters supplied with d-c power and arranged in two vertical configurations: flush mounted on a circuit board substrate or protruding from the substrate about 1 mm. Heat transfer characteristics (midpoint) were obtained with varying height (1 mm to 80 mm) and width (2.5 mm to 70 mm) in R-113. Two types of incipient boiling temperature overshoot were observed with saturated boiling. The inception of boiling depended greatly on the location of the active boiling sites on the heater. For arrays, the inception of boiling for the top heater took place at lower superheat than for the bottom heater. Heater size had no effect on established boiling, in contrast to results reported previously in the literature. The critical heat flux for wide heaters increased with decreasing heater height, as expected. The critical heat flux also increased with decreasing width. Correlations are presented that describe these effects.