Universal surface reaction model of plasma oxide etching

Abstract

We propose a universal surface reaction model without any ad-hoc assumptions for fluorocarbon (FC) plasma oxide etching. A self-consistent numerical algorithm was developed to predict the deposition and etch yields simultaneously from our model considering the passivation layer and mixed layer. The internal model variables such as surface coverages showed consistent results under a wide range of FC plasma conditions. This model predicts the transition conditions between deposition and etch yield and the FC passivation layer thickness during the etching process. Finally, quantitative verification of the proposed model was performed through comparison to various FC plasma experimental data.

Fast and realistic 3D feature profile simulation platform for plasma etching process

“…Using the results depicted in figure 4(a), the etch and deposition yields were estimated as functions of the incident ion energy and polymer radicalto-ion flux ratio (R CFx ), as shown in figure 4(b). The estimated modeling results show good agreement with the experimental data of CF 2 [32], C 4 F 6 [22] and C 2 F 6 [33] plasmas reported in the literature. Therefore, the two-layer-based surface kinetic model, coupled with the passivated polymer thickness shown in figure 4(a), can be applied to a wide range of plasma conditions.…”

“…Recently, we developed a universal surface reaction model to replace the semi-empirical equation ( 9) [22] but we can also extend this work to more sophisticated computations. In addition, we use the detailed kinetic surface reaction model shown in table 1 instead of the global surface reaction model in the mixed layer to consider realistic surface reaction chemistry.…”

“…The numerical solution on the surface reaction model in table 1 is obtained by the Cantera code [29]. Finally, we follow the same numerical procedure to obtain the etch and deposition rates as in a previous study [22].…”

“…For the plasma HAR etching process, the etching process of a composite material comprising a polymer passivation layer and mixed layer must be considered in this simulation. Because it is difficult to account for these surface reaction phenomena with the level set algorithm, we developed a two-layer-based surface reaction model [21,22] and demonstrated how to integrate this model into our simulation platform.…”

Phenomenological model for predicting C x H y F z + ion etching yields of SiO2 and SiN x substrates

“…As for FC and HFC plasma etching, many experiments have been conducted, and surface reaction models have been suggested. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] During etching using FC and HFC gases, the substrate material, such as Si, SiO 2 , or SiN x , is covered with a fluorocarbon layer (CF layer), which is modified by incident chemical species consisting of carbon, fluorine, and hydrogen atoms. The CF layer has different thickness depending on the underlying material, and strongly affects the etch rate of the substrate material.…”