Analysis of conjugate heat transfer in a vented process chamber for thin-film deposition in semiconductor fabrication

Conjugate heat transfer in vented deposition chambers is a complex transport phenomenon involving strong coupling among forced convection, natural convection, and heat conduction through solid components. In this work, we investigate this behavior in a vented process chamber designed for thin-film deposition applications in semiconductor manufacturing. The model is motivated by laser chemical vapor deposition systems, where silane ( S i H 4 ) enters the chamber through a top inlet and the exhaust stream exits from a lower-right outlet. A silicon substrate is embedded within the chamber, and the laser heating process is represented by a prescribed heated wall, whereas all other walls are kept at ambient temperature. Assuming constant thermophysical properties and two-dimensional steady-state incompressible flow with no radiation effects, the governing incompressible Navier–Stokes equations and the energy equation are discretized using the Galerkin finite element method. The study systematically evaluates the effects of substrate length-to-width ratio, Reynolds number, Richardson number, and volumetric heat generation in the substrate. The results show that the substrate aspect ratio is a key design parameter that modifies the recirculation pattern and governs the heat-transfer distribution. Among the considered configurations, substrates with comparable length and width yield superior thermal performance. The heat-transfer rate reaches its maximum near R i = 1 , highlighting the beneficial balance between inertia-driven and buoyancy-driven transport. To extend the applicability of the numerical results, a Genetic Algorithm-based predictive model is introduced to establish a correlation for heat-transfer estimation in the investigated vented chamber configuration.