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Semiconductor thin film manufacturing has been a worldwide research hotspot, metal organic chemical vapor deposition(MOCVD) due to the manufacture of good uniformity of large-size film, and both high purity, material changes and high flexibility, which the main process for the current LED epitaxial industry. But also for the development of LED industry in recent years, MOCVD process is also a certain degree of maturity.
Most of the vertical MOCVD analysis of the inlet boundary using gas out of slot as the entrance boundary conditions, rarely discuss the gas flow above the chamber, so this study uses finite element analysis software to comparison with fluid from a round jet, and gas flow after inlet diversion. In this study, a set of inlet diversion system is designed. The system can be divided into two layers, the upper and the lower layers are respectively simulated. Flow simulation, the purpose of this study is to enhance the flow rate uniformity of the chamber inlet, thereby increasing the film growth uniformity.
According to the simulation results, if the diversion angle of upper baffle plate and bottom is 22.5 degrees, the optimal velocity distribution of the chamber inlet is obtained. The results of this part also correspond to the experimental results. By adjusting the slot width, it can be found that reducing the slot width requires a high pressure difference to diffuse the gas into the chamber, thereby increasing the uniformity of the chamber inlet flow rate. The lower baffle design, found to increase the six-entry design, can reduce the lateral slot flow rate higher problem, and finally adjust the different channel and slot width ratio, it can get a single slot the best flow rate uniformity.
For double layer diversion design, it can be found that TMAl is suitable for passing through the upper baffle, and NH3 is suitable for passing through the lower baffle by gas configuration simulation. Apply mass transfer simulation, the results show that uniformity of the film is increased to 8.8% after the double-layer diversion is carried out, and the uniformity of the organic matter is increased. | en_US |