Tech Next Lab

(TNL-TCAD: Nano Scale Semiconductors Technologies)

In the semiconductor industry metal-organic chemical vapor deposition (MOCVD) is a significant chemical process for manufacturing special materials and high-tech devices. The operation conditions of MOCVD processes include the reaction mechanisms, and transport phenomena are profoundly affected by the gas inlet flow rate, operating pressure and temperature, and reactor geometry configurations. The MOCVD process involves complex transport phenomena such as momentum, heat, mass and chemical deposition reactions, the optimal film growth condition can hardly be determined based on an oversimplified model.

Every MOCVD process requires that precursors are transported from the location where the gases are supplied (inlet manifold, showerhead, injector) to the surface on which deposition must occur (substrate, wafer): that is, mass transport must occur.

The TNL-Chemical Kinetics module is designed to facilitate simulations of elementary chemical reactions to predict the reaction rates. It helps a user to work efficiently with large systems of chemical reactions, develop and optimize representations of systems of equations that define a particular problem. It provides a flexible and powerful tool for incorporating complex chemical kinetics into simulations of atoms and molecules dynamics. The Interpreter reads a symbolic description of a user-specified chemical reaction mechanism. The mechanism includes species information, as well as reaction path and rate descriptions.

To save the design cost and development time, use of computer-aided design (CAD) methodologies through a detailed working principle of MOCVD processes are of great importance. An important role in determining an optimal operating condition of an MOCVD reactor for film growth of a special material is essential requirement.

TNL MOCVD process simulators include two separate reactors geometry configurations i.e. TNL-Injector simulator (horizontal flow) and TNL-Showerhead simulator (Vertical flow). The horizontal MOCVD reactor geometry configuration resembles with the AIXTRON AIX 200/4 horizontal MOCVD reactor geometry. However, TNL-Showerhead process include the vertical component velocity of a point over the substrate is only dependent on vertical distance and is independent of radial distance. The ceiling height of the reactor play important effects on residence time and the mass transport process. The showerhead MOCVD reactor has a short residence time and diffusion plays an important role in axial transport, while both diffusion and convection are important in radial transport.