Chemical Vapor Deposition1267Gas streamSusceptorWafer3451. Transport of reactants to the deposition region.*2. Transport of reactants from the main gas stream through the boundary layer to the wafer surfacelayer to the wafer surface.*3. Adsorption of reactants on the wafer surface.*4. Surface reactions, including: chemical decomposition or reaction, surface migration to attachment sites (kinks and ledges); site incorporation; and other surface reactions (emission and redeposition for example).*5. Desorption of byproducts.6 Transport of byproducts through boundary layer6. Transport of byproducts through boundary layer.7. Transport of byproducts away from the deposition region.