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Tergeo plasma cleaner operator’s manual
Revision: B3, Year 2020
Chapter 6
Introduction
6.1 Introduction to plasma
Plasma is an ionized gas phase substance that consists of ions, electrons, neutral atoms and
molecules that maintain charge neutrality. To ignite a plasma, free moving electrons will be
accelerated by an external radio frequency wave and acquire enough energy to ionize the process
gasses. If the pressure is too high (higher than 1 Torr), the mean free path of electrons will be too
short for electrons to accumulate enough energy to ionize the process gasses. If pressure is lower
than 1 mTorr, mean free path may become so long that energetic electrons might be lost on
electrodes or chamber wall before they can ionize process gas molecules. Optimal chamber
pressure for plasma processing is around 50~300mTorr. For oxygen gas, optimal pressure range is
70~150mTorr.
6.2
Introduction to system
Tergeo plasma system consists of the following components: a sample chamber, a remote plasma
source, a rf power supply, rf electrodes, rf antennas, a gas delivery system, plasma sensors, system
control electronics and a touch screen user interface.
Figure 1, Tergeo series plasma cleaner.
The sample chamber is composed of a high purity quartz tube, a front cap with view port for Tergeo and
Tergeo-plus, a back flange. The front cap for Tergeo-EM plasma cleaner has been modified to accept
TEM rod from major TEM vendors. There are two different chamber sizes available. The quartz chamber
in basic Tergeo and Tergeo-EM plasma cleaner has an inner diameter of 110mm. The inner diameter of
the quartz tube in Tergeo-plus plasma cleaner is 160mm. The depth of the sample chamber is 280mm.
RF power supply has two options, 75watt or 150watt. Some models may be equipped with automatic
impedance matching capability if the option is purchased.
Up to three mass flow controller (MFC) regulated gas delivery ports are available. The number of gas
input port may vary depending on purchasing options. The range of the MFC is 0~100 sccm. If the
