We have developed a simulation for predicting reactive ion etching (RIE) topography, which is a combination of plasma simulation, the gas reaction model, the sheath model and the surface reaction model. The simulation is applied to the SiO 2 etching process of a high-aspect-ratio contact hole using C 5 F 8 gas. A capacitively coupled plasma (CCP) reactor of an 8-in. wafer was used in the etching experiments. The baseline conditions are RF power of 1500 W and gas pressure of 4.0 Pa in a gas mixture of Ar, O 2 and C 5 F 8 . The plasma simulation reproduces the tendency that CF 2 radical density increases rapidly and the electron density decreases gradually with increasing gas flow rate of C 5 F 8 . In the RIE topography simulation, the etching profiles such as bowing and taper shape at the bottom are reproduced in deep holes with aspect ratios greater than 19. Moreover, the etching profile, the dependence of the etch depth on the etching time, and the bottom diameter can be predicted by this simulation.

An inductively coupled plasma (ICP) is one of the candidates for a high density, large area and uniform plasma source for use in plasma processing even under low pressure conditions. We have developed a two-dimensional and time dependent model for a collision dominated ICP, taking into consideration electron transport in both the electric and magnetic fields, based on the relaxation continuum (RCT) model in a self-consistent manner. The 2D-space and time structure of an ICP, driven by a frequency of 13.56 MHz and a current amplitude of 10 A at 0.3 Torr in Ar is mainly discussed. In particular, a space potential with a double frequency time variation, at a plasma density of 1011 cm-3 is clarified as well as a potential distribution of the insulating wall of ICP. The importance of the power deposition by E r ×B z drift of electrons in front of the side wall, in addition to E θ drift is pointed out in terms of the plasma maintenance.

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Articles you may be interested inInfinitely high etch selectivity during CH 2 F 2 / H 2 dual-frequency capacitively coupled plasma etching of silicon nitride to chemical vapor-deposited a -C J. Vac. Sci. Technol. A 28, 755 (2010); 10.1116/1.3430551 TiSiN films produced by chemical vapor deposition as diffusion barriers for Cu metallization Microscopic mapping of specific contact resistances and long-term reliability tests on 4H-silicon carbide using sputtered titanium tungsten contacts for high temperature device applications With the shrinking design rule of semiconductor devices, the aspect ratios of contact holes that connect transistor electrodes to wirings have exceeded 10 at a design rule less than 0.15 m. The contact is formed through sequential processes of reactive ion etching ͑RIE͒, TiN sputtering, and tungsten chemical vapor deposition ͑W-CVD͒. In such a formation process, a contact hole with a large bottom diameter is required to reduce contact resistance. We developed a contact simulation method for optimizing contact formation. This contact simulation involves sequential simulations of RIE, TiN sputtering, and W-CVD processes, which adopt a particle model based on the Monte Carlo method. These topography simulations were calibrated using experimental results, and each simulation was combined in order to calculate these sequential simulations. We calculated the dependences of etching and W-CVD filling profiles on contact hole depth. The simulation profiles of etching and W-CVD filling were in agreement with the experimental results. The sequential simulations showed that W disconnection occurs at over 2.5 m contact depth with a aspect ratio of 19.2 and the contact resistance increases markedly.