Ion energy control and its applicability to plasma enhanced atomic layer deposition for synthesizing titanium dioxide films

Self Cite

Effects of driving frequency on the plasma density in capacitively coupled plasmas (CCPs) have been investigated at Torr-order pressures which are commonly used in film deposition processes (1 Torr = 133.322 Pa). Using a particle-in-cell, Monte Carlo collision model, frequency trends of the electron density have been simulated in Ar and H2/Ar CCPs from 300 kHz to 27 MHz. The results show a local maximum of the electron density at 450 kHz and a local minimum around 4 MHz in both the Ar and H2/Ar plasmas. In particular, in the H2/Ar plasma, 450 kHz is more effective to produce higher density plasma than 13.56 MHz at Torr-order pressure although it is generally believed that higher density plasma can be obtained as the driving frequency increases. The ion density starts to oscillate between electrodes around 4 MHz since it is close to the ion plasma frequency. Thus, the plasma bulk collapses resulting in the low plasma density. On the other hand, at 450 kHz, in addition to the gamma process, the re-formed plasma bulk contributes to high density plasma.

Section: Simulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of driving frequency on plasma density in Ar and H₂/Ar capacitively coupled plasmas at Torr-order pressure

Denpoh

2020

Self Cite

“…An atomic layer process (ALP) such as the atomic layer deposition and the formation of ultra-thin films has been introduced for realizing 3D nanoscale processing. [1][2][3][4][5] The direct plasma processing (DPP) technique, the so-called plasma-enhanced chemical vapor deposition (PECVD) is employed in the ALP. In the DPP technique, wafers are directly exposed in the process plasmas, and accurate control of the collective behavior of ions, radicals, electrons, and neutral particles becomes difficult.…”

Section: Introductionmentioning

confidence: 99%

Simulations of novel compact separator for extracting specific reactive ions from large plasma source

Kanki¹,

Himura²

2022

A new remote dry processing with focusing and deflection system is proposed to accurately control the energy, flux, and arrival position of reactive particle species on nanoscale. The trajectory simulations of the negative ion extraction and transport for designing a compact separator based on the concept are performed using the SIMION software. In the compact separator, the ion beam extracted from a plasma source can be deflected in two stages through two pairs of magnets by selecting only specific ions so that it can be laterally drawn out. It is shown from results of the simulation that the ion beams with the good focusing properties, the high directivity, and the sufficient current amount can be successfully extracted from the plasma source and transported to the reactor vessel through the focusing and deflection system.

“…An atomic layer process such as atomic layer deposition and the formation of ultra-thin films is used to realize 3D nanoscale fabrication. [1][2][3][4][5] However, with a direct plasma processing technique, namely, plasma-enhanced chemical vapor deposition (PECVD), a processed target (wafer) is placed in a plasma source. The wafer is directly exposed to the plasma, and it is difficult to precisely control the collective behavior of the ions, radicals and electrons contained in the plasma.…”

Section: Introductionmentioning

confidence: 99%

Simulations of negative ion extraction and transport for developing novel remote reactive ion processing system

Kanki

Himura

Tsumori

et al. 2020

A novel remote dry processing of specific reactive negative ions with a deflection and focusing system is being developed to precisely control their energy, flux and reaching position on the nanoscale. The trajectory simulations of the negative ion extraction and transport for the design of this processing apparatus have been carried out using SIMION software. It is found from the simulation results that the ion beams with good focusing characteristics, high directivity and appropriate current amount can be successfully extracted from the plasma source and transported to the reactor chamber through the deflection and focusing system. The simulation results of O− ion beam exhibit that the extraction and transport characteristics of the flat intermediate electrode are superior to those of the oblique one.