An experimental method named the 'macro/microcavity method' (Mh-IC) has been used for over 8 years for studying the relative contributions of gas-phase and surface reactions and for determining the sticking probability of growth species in chemical Vapor deposition (CVD) reaction systems. The MMC method provides two well-defined reaction fields: the space between multiple stacked substrates and trenches etched into the substrates, which have millimeter and submicron characteristic dimensions, respectively. To analyze the chemical processes with the MMC method a mathematical model was developed to relate the film growth-rate profile in the macrocavity to the surface-to-volume ratio (S/V) of the macrocavity. This gives the relative contributions of gas-phase and surface reactions to the film growth. Another analytical model based on Monte Carlo simulations correlates the film profile in the microcavity to the sticking probability of the deposition species. The combination of these two analysis techniques presents an overall picture of the reaction scheme. This paper reviews the application of the MMC method in analyzing the chemical mechanisms in SiH4/O2-SiO2, SiH4-Si, Si2H6/C2H2-SiC, and TEOS-SiO2 CVD systems.