Remarkable changes of the electron temperature and the plasma density by increasing bias power were observed in low gas pressure inductively coupled plasma (ICP) by the measurement of electron energy distribution function (EEDF). As the bias power increases, the electron temperature increased with accompanying the evolution of the EEDF from a bi-Maxwellian to a Maxwellian distribution. However, a different trend of the plasma density was observed with a dependence on the ICP powers. When the ICP power was relatively small or the discharge is in capacitive mode (E mode), the plasma density increased considerably with the bias power, while decrease of the plasma density was observed when the discharge is in inductive mode (H mode). The change of the plasma density can be explained by the balance between total power absorption and power dissipation.

Effects of rf-bias power on plasma parameters in a low gas pressure inductively coupled plasma

The effect of radio-frequency bias on electron density in an inductively coupled plasma reactor was measured using a wave cutoff probe, over a wide range of conditions in pure Ar, pure CF4, and 50%–50% mixtures of Ar∕CF4, at pressures of 0.7–4.0Pa (5–30mTorr), bias frequencies of 10–30MHz, bias voltages up to 750V, and inductive source powers of 50–300W. Also, at selected experimental conditions, comparisons with Langmuir probe measurements were made. Two types of bias-induced changes in electron density were detected. First, at high source powers, we observed a bias-induced decrease in electron density, which had a slow time response (several minutes), a linear dependence on bias voltage, and little or no dependence on bias frequency or pressure. This decrease is a gas composition effect caused by etch or sputter products liberated from the wafer surface. Second, at low source powers, we observed a faster, bias-induced increase in electron density, which was proportional to the bias frequency and the squ...

The effects of radio-frequency bias on electron density in an inductively coupled plasma reactor

Effects of RF bias power on electron energy distribution function and plasma uniformity in inductively coupled argon plasma

This paper presents a film transfer process to integrate barium strontium titanate (BST) metal–insulator–metal (MIM) structures with surface acoustic wave (SAW) devices on a lithium niobate (LN) substrate. A high-quality BST film grown on a Si substrate above 650 °C was patterned into the MIM structures, and transferred to a LN substrate below 130 °C by Ar-plasma-activated Au–Au bonding and the Si lost wafer process. Simple test SAW devices with the transferred BST variable capacitors (VCs) were fabricated and characterized. The resonance frequency of a one-port SAW resonator with the VC connected in series changed from 999 to 1018 MHz, when a dc bias voltage of 3 V was applied to the VC. Although the observed frequency tuning range was smaller than expected due to the degradation of BST in the process, the experimental result demonstrated that a tunable SAW filter with the transferred BST VCs was feasible.

https://iopscience.iop.org/article/10.1088/0960-1317/23/2/025005/pdf

Integration of BST varactors with surface acoustic wave device by film transfer technology for tunable RF filters

Computer simulations are performed for an argon inductively coupled plasma (ICP) with a capacitive radio-frequency bias power, to investigate the bias effect on the discharge mode transition and on the plasma characteristics at various ICP currents, bias voltages, and bias frequencies When the bias frequency is fixed at 1356 MHz and the ICP current is low, eg, 6 A, the spatiotemporal averaged plasma density increases monotonically with bias voltage, and the bias effect is already prominent at a bias voltage of 90 V The maximum of the ionization rate moves toward the bottom electrode, which indicates clearly the discharge mode transition in inductive/capacitive discharges At higher ICP currents, ie, 11 and 13 A, the plasma density decreases first and then increases with bias voltage, due to the competing mechanisms between the ion acceleration power dissipation and the capacitive power deposition At 11 A, the bias effect is still important, but it is noticeable only at higher bias voltages At 13 

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Fluid simulation of the bias effect in inductive/capacitive discharges

The inductively coupled plasma (ICP) etching behavior of Ba05Sr05TiO3 (BST) thin films has been characterized with Cl2/Ar gas mixtures by varying the process parameters such as chamber pressure, ICP power, and substrate bias rf power The etching characteristics of BST were investigated in terms of etch rate, etch profile, surface residue, and electrical properties The results obtained can be further interpreted by the plasma properties (ion flux and dc bias) in situ measured by a Langmuir probe Quantitative analysis of the plasma-induced damage in the Pt/BST/Pt capacitor was attempted to discuss the mechanism of leakage current density and dielectric constant with various substrate bias rf power and ICP power levels Finally, optimization of the etch parameters for fabricating BST capacitors was performed to minimize the plasma-induced damage The optimum condition appears to be under a 30% Cl2/(Cl2+Ar) gas mixture, ICP power of 800 W, substrate bias rf power of 100 W, and chamber pressure of 067 Pa

Etching characteristics and plasma-induced damage of high-k Ba0.5Sr0.5TiO3 thin-film capacitors

Deep etching of GaP was performed by high-density plasma using an inductively coupled plasma (ICP) etcher. The effects of process parameters such as the gas combination (Cl2/N2), chamber pressure, inductive power and rf chuck power were investigated. The dependences of the etch rates and selectivity on the rf chunk power and chamber pressure were studied using the response surface method. The results obtained can be further interpreted by the plasma properties (ion flux and dc bias) measured in situ by a Langmuir probe. With an increase in the chamber pressure to 4 Pa, a maximum etch rate of ∼7.5 μm/min for GaP can be obtained under a Cl2/(Cl2+N2) gas mixture of 0.8, ICP power of 800 W, and rf power of 100 W. The increase in the etch rate with an increase in chamber pressure indicates that reactive radicals are the main etching species. To clarify the etching mechanism, the surface reaction of GaP under various Cl2/(Cl2+N2) gas mixtures was investigated by x-ray photoelectron spectroscopy and atomic force...

Y. H. Liu

Papers

Etching characteristics and plasma-induced damage of high-k Ba0.5Sr0.5TiO3 thin-film capacitors

Deep etch of GaP using high-density plasma for light-emitting diode applications