Determination of SF6 reactive ion etching end point of the SiO2/Si system by plasma impedance monitoring

Raman scattering analysis of silicon dioxide single crystal treated by direct current plasma discharge

“…Plasma is widely used tool for surface modification of SiO 2 layers. [3][4][5] As the dimensions of electronic devices decrease, the role of plasma etching techniques becomes more crucial. Improving knowledge in this field is important in optimizing and controlling plasma etching processes.…”

Monitoring of Condition of Deposited Film Causing Particles in Plasma Etching by Using Practical Load Impedance Monitoring Method

“…In this study, we demonstrate a method for monitoring the inner wall condition with the load impedance monitoring system. Plasma impedance monitoring methods for plasma etching have been studied for end point detection [15][16][17][18] , real-time monitoring of electrode voltage and current 19,20) , and estimation of plasma parameters such as electron density. Load impedance monitoring can also be applied to monitoring inner wall because the load impedance in capacitively coupled plasma (CCP) discharge mainly depends on sheath capacitance 21) , which re‰ects not only the plasma discharge conditions but the inner wall conditions, including theˆlm.…”

“…Load impedance monitoring can also be applied to monitoring inner wall because the load impedance in capacitively coupled plasma (CCP) discharge mainly depends on sheath capacitance 21) , which re‰ects not only the plasma discharge conditions but the inner wall conditions, including theˆlm. However, conventional impedance measurement methods [15][16][17][18][19] using high-voltage and high-current probes installed between the matching circuit and the powered electrode are impractical for mass-production equipment. This is because it is di‹cult to modify the existing equipment to install the probes and the modiˆcation can lead to the change in the impedance matching condition and the process conditions.…”

Note: Practical monitoring system using characteristic impedance measurement during plasma processing

“…The system can measure the time variations of characteristic and load impedances even while the plasma is generated. The plasma impedance monitoring (PIM) method, which is categorized as non-invasive measurement, has been widely studied in plasma etching process; for example, end-point detection [1][2][3][4][5][6] and real time monitoring for electrode voltage and current. 7,8 In addition, many experimental and circuitmodel-based studies have also been performed using the plasma impedance to estimate plasma parameters, such as the electron density, the electron-neutral collision frequency, 9 the sheath voltage, 10 and the ion energy distribution function.…”