Abstract
The authors developed several experimental technique to elucidate the main reaction path ways to deposit thin films by chemical vapor deposition (CVD). These techniques includes the analyses of step coverage profile in micron sized trenches, growth rate profiles of selective growth, growth rate profiles in tubular reactor, and the effect of residence time to the film growth rate. The step coverage profiles and growth rate profiles in selective area growth will provide information on surface reactions, while the other analyses will provide the information of gas-phase and surface kinetics. The combination of these techniques in different size dimension (multi-scale analysis) is a powerful technique to elucidate the important reaction paths in CVD. In this work, a-C:F film deposition by plasma-enhanced CVD (PECVD) and epitaxial growth of InGaAsP thin films by metal-organic vapor phase epitaxy (MOVPE) were chosen as the example for the demonstration of multi-scale analysis. The selective area MOVPE (SAMOVPE) shows non-uniformity in the epitaxial growth area, mostly due to the gas phase concentration distribution of film forming species. This micro-scale profile was mostly controlled by the ratio of diffusion coefficient and the surface reaction rate constant of film forming species, while the growth rate profile in MOVPE reactor (macro-scale) was governed by the diffusional mass transport. Thus the combination of these analysis can give the information of surface reactivity of film forming species. The residence time dependencies of PECVD growth rate and chemical species in gas phase give the information on overall reaction mechanism. The growth rate profile inside the micron size "test structure" gives the detail information of surface reaction mechanism. This is another demonstration of multi-scale analysis.
