When the wafer is ready, the next step is the patterning of the circuit pattern designed in the "design / mask creation" step. Before patterning, the wafer is placed in a high-temperature furnace to make the silicon react with oxygen or water vapor, and to develop oxide films on the wafer surface (thermal oxidation). These oxide films are used for the insulation of transistor gates and for the insulation of interconnect layers. To develop nitride films and polysilicon films, the chemical vapor deposition (CVD) method is used, in which a gaseous reactant is introduced to the silicon substrate, and chemical reaction with the substrate surface is prompted by high temperature or plasma. The metallic layers used in the wiring of the circuit are also formed by CVD, spattering (PVD: physical vapor deposition), or other plating methods.
Diffusion Furnace (Diffusion Process)
Deposition
Terms
