Quantum materials often have unique electrical properties that are directly linked to quantum mechanical effects.  Here, we study one such material, cadmium arsenide (Cd₃As₂).  Cd₃As₂ is a three-dimensional Dirac semimetal in its bulk form, but by growing Cd₃As₂ as a thin film, we can tune its topological phase by means of heterostructure engineering.  The main synthesis strategy is molecular beam epitaxy (MBE).  This technique allows us to produce epitaxial thin film heterostructures, which consist of a GaSb substrate, a buffer layer of Al_1-xIn_xSb, a Cd₃As₂ film, and finally a cap layer of GaSb.  Various challenges exist in MBE growth of Cd₃As₂.  One challenge is that the buffer layer should lattice match cadmium arsenide.  The ideal alloy composition must therefore be fine-tuned.  We have explored the effects of two parameters on the quality of the buffer layer, (1) the substrate temperature, and (2) the antimony flux stabilization time.  We monitor the growth in situ by reflection high energy electron diffraction (RHEED).  After growth, we use high resolution x-ray diffraction (HRXRD) and atomic force microscopy (AFM) to characterize the film quality.  We found that an optimal buffer growth temperature is near 380 °C, while higher temperatures reduce the crystalline quality of the buffer.  We have also tested various antimony effusion cell stabilization/warm-up times, which affects the stability of the antimony atomic flux over time.