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Modeling of dry etching processes requires a detailed understanding of the relevant reaction mechanisms. This study aims to elucidate the gas-phase mechanism of reactions in the chemical dry etching process of SiO2 layers which is initiated by mixing NF3 gas with the discharged flow of an NH3/N2 mixture in an etching chamber. A kinetic model describing the gas-phase reactions has been constructed based on the predictions of reaction channels and rate constants by quantum chemical and statistical reaction-rate calculations. The primary reaction pathway includes the reaction of NF3 with H atoms, NF3 + H → NF2 + HF, and subsequent reactions involving NF2 and other radicals. The reaction pathways were analyzed by kinetic simulation, and a simplified kinetic model composed of 12 reactions was developed. The surface process was also investigated based on preliminary quantum chemical calculations for ammonium fluoride clusters, which are considered to contribute to etching. The results indicate the presence of negatively charged fluorine atoms in the clusters, which are suggested to serve as etchants to remove SiO2 from the surface.

Modeling of dry etching processes requires a detailed understanding of the relevant reaction mechanisms. This study aims to elucidate the gas-phase mechanism of reactions in the chemical dry etching process of SiO

Many studies have been done to apply potential of Plasma Doping to manufacturing semiconductor devices. But some development problems about mass production are still left unsolved. One of the problems is that it is more difficult for Plasma Doping to control dosage. To clear this problem we investigated a dominant mechanism of mixing dopant atoms (boron) in silicon atoms, using inductively coupled plasma, radio frequency bias and B 2 H 6 gas. And it is shown that main implantation mechanism of this plasma doping is the collision between B x H y * and biased Ar+: “knock-on phenomenon”. We presented new doping procedure “2STEP Process”, where B x H y * deposition coating and knocking-on the film by Ar+ accelerated with RF bias were completely separated. By using “2STEP Process”, it is shown that dosage can be controlled by deposition thickness and depth profile can be controlled by bias voltage.

The new medium current ion implanter SOPHI‐200 has been developed. By newly designed low aberration optics, high performances have been obtained at a compact implanter system with light tuning. ULVAC’s wafer handling system, which is production proved, has realized the direct implantation to the ultra thin wafer for power device manufacturing. Overview of the system and the performance characteristics will be discussed.

Real‐time optimization for optical parameters, such as applied voltage to the electrostatic quadrupole lens, has been realized by using newly developed high‐speed computation algorithm for charged particle beams. The virtual optimization code has been incorporated in the control system of SOPHI‐200, which is the ULVAC’S new medium current ion implanter. Automatic setup within 5minutes is achieved for any recipe of implantation.

We are researching and developing the stencil mask ion implanter (SLIM), which enables direct implantation on wafer through a stencil mask. This technology eliminates photo resist lithography processes for ion implantation. The basic performances of SLIM as an ion implanter were the same level as those of conventional ion implanters. “SLIM process” has an effect of shortening the process time to 1/4. We present the solution to magnification alignment error, and also introduce three examples of applying this process: reduction of the threshold voltage errors, formation of ring ion implantation area and formation of isolated diffusion layer.