چارچوب شبیه سازی یکپارچه پردازش پلاسما، ایجاد ارتباط بین مدل پلاسما در مقیاس ابزار دو بعدی با مقیاس ویژگی های شبیه سازی

An integrated, extensible, full featured inductively coupled plasma (ICP) reactor simulation environment with a 2D feature scale etch simulator is presented. It incorporates tool scale plasma chemistry and feature scale trench evolution. Flexibility is achieved by software plugins for gas phase and surface reaction models that can be freely adapted and extended to a wide range of reactant-material systems. Available plasma chemistries cover SF6, C4F8 and O2 plasmas and are implemented by global models capturing both gas phase and wall-surface reaction kinetics. Surface reaction models for Si, SiO2, and organic polymers have been developed. Validation of simulation agreement with experimental data is presented for etching of Si by SF6 plasma.

In recent years significant progress in simulation of plasma reaction equipment and feature etching [1] was made. Due to complexity of physical effects and chemical processes, simulation software to date is limited to either tool size plasma simulations or feature size profile evolution. Joined simulators are few in number and are restricted to relatively large feature sizes. In this work we present a simulator which brings together (1) tool size gas phase and sheath models, (2) feature scale species transport modules, and (3) surface reaction modules.

A plasma processing simulator for Si etching by SF6 plasmas was developed. The simulator consists of a gas phase model, a sheath model, a feature scale model, and surface chemistry models. The simulator requires physical parameters and constants, tool parameters such as reactor geometry, experimental parameters, sample material, and initial shape of the mask as inputs. The final output of the simulator is the profile of the etched trench as well as gas phase and surface properties. The simulator was validated with the etching of silicon by SF6 plasmas by comparing the experimental profiles with the simulated ones. It was found that the simulator reproduces the profiles of the SF6 etching experiments with fair agreement. The depth of etching was faithfully reproduced for different initial feature sizes and different r.f power settings. Also, the simulated profile shape, as represented by the ratio of undercut to depth of etching, is in good agreement with the experiments. The agreement is more accurate for the higher DC bias settings. Especially for the 0 V DC bias settings, deviations in the profile shape and the depth of etching exist. This may be attributed to the approximations used in the sheath and surface models. As a wide range of feature sizes and different recipes can be faithfully reproduced by the simulator without additional “tuning” of the physical or tool parameters, we concluded that we have considered the most important effects for silicon plasma etching with SF6 in our model. Research continues to identify and integrate all additional effects influencing the shape and surface properties of etched structures.