No abstract

A simple method for the estimation of ion/radical fluxes in an ion-assisted etching process was developed for SF 6 /O 2 /Si etching utilizing the difference in etching mechanism between SiO 2 mask and the silicon substrate. It was derived that F coverage of a silicon surface is approximately a linear function of the selectivity of the two materials, from which the incident ion flux and F flux are calculated. The selectivity-to-coverage proportional constant was determined using a topography simulator so that the general trend of etching profiles matched those of the experiment. The obtained fluxes showed reasonable qualitative trends in terms of reactor operational conditions and reactor parameters. The feature profiles simulated by the topography simulator using these flux values were in good agreement with those of scanning electron microscopy (SEM) experimental data over a wide range of operating conditions and machine configurations. #

No abstract

No abstract

A new topography simulation method has been developed for SF 6 /O 2 /Si plasma etching of trench gates in IGBTs. This method calculates the ion and fluorine radical flux parameters required for the topography simulation from the etching rate and selectivity obtained from simple basic experiments. The O radical flux was assumed as a function of the operating conditions and the function form was determined by fitting etching profiles of the topography simulation to those of the experiment. The model used in the topography simulation was improved in terms of the etching yield dependence on the ion incidence angle. As a result, a large variety of profiles could be simulated accurately under different operational conditions.