Method and apparatus for controlling coating thickness

摘要

The coating thickness and uniformity of spin-on deposition layers on semiconductor wafers is controlled through the in situ control of the viscosity and homogeneity of the mixture of precursor material and solvent material. The thickness of the deposited material is selected and the viscosity required at a given spin rate for the selected thickness is automatically mixed. Sensing and control apparatus are employed to ensure that the uniformity and viscosity required is maintained before dispensing onto said semiconductor wafer. Low-K dielectric materials of selected thickness are deposited in a uniform coating.