Control of Plasma Kinetics for Microelectronics Fabrication.

[摘要] The fluxes of radicals and ions to the wafer during plasma processing of microelectronics devices determine the quality of the etch or deposition. These fluxes are largely controlled by controlling the electron energy distribution (EED) which determines the dissociation patterns of feedstock gases. Also, the quality of the process is in large part determined by the ability to control the ion energy distribution (IED) onto the wafer. In this thesis, the possibilities of controlling EED and IED are modeled using a two-dimensional plasma equipment model.The techniques to control the EED include a magnetic field, beam electrons and a pulsed power source. Due to the magnetic confinement, the EED varies with position of the chamber depending on the pressure and power. Using beam electrons also provides a possibility to customize EED by delivering the energy to the bulk electrons through the e-e collisions.In dual frequency capacitively coupled plasmas (DF-CCP), the pulsed power is one technique being investigated to provide additional degrees of freedom to control the EED and IED. By using pulsed power, electron sources and sinks do not need to instantaneously balance – they only need to balance over the longer pulse period. This provides additional leverage to customize EED and IED. As an application, the etching properties were also investigated in the DF-CCP using pulsed power. In the pulsed operation, there are typically two phases; deposition and etching. As a result, using pulse power provides one with the ability to control the balance between the etching and deposition, which enables us to manipulate the etching profile. It was found that sidewall bowing can be suppressed by pulsing.

[发布机构] University of Michigan

[效力级别] Microelectronics Fabrication

[关键词] Low Temperature Plasma;Microelectronics Fabrication;Control of Plasma Kinetics;Nuclear Engineering and Radiological Sciences;Engineering;Nuclear Engineering & Radiological Sciences