Glow discharge basics

4 Glow discharge basics 11.3.4.1 Types of glow discharge 

At low pressures an eleetron generally hits at most one gas atom as it transits between the cathode and anode. This makes ionization of the gas weak and dependent entirely on gas pressure and the number of electrons leaving the cathode. For a given emission current, ionization depends linearly on pressure. Every ion created generates another electron striking the anode so current also generally 

As the pressure increases electrons are likely to interact with more than one gas atom on their way from anode to cathode, and thus can form multiple ions. Furthermore, electrons generated by ionization events near the cathode can go on to cause ionizations themselves. Eventually ionization events become so common that ions are formed in the gas as fast as they are lost to the surrounding surfaces or to recombination with electrons. When this happens the discharge has a significant 

We saw in Equation 10.3 that the flux of all gas species crossing a plane per second can be written in terms of the partial pressure as  

Equation 11.11 is a true equation but not generally terribly useful because we typically do not know the electron temperature very well. It can be measured with some effort but because it depends on many process parameters, a measured value is not very helpful in general. 

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Although the chemistry and physics of a glow discharge are extraordinarily complex, the plasma performs only two basic functions. First, reactive... 

In addition to thermally-created CVD films, much work has been done using glow discharges to modify the deposition. Therefore, Chapter 2 reviews the fundamentals of plasma-enhanced CVD (PECVD). Initially, the basic character of a plasma is covered. Then we discuss the influence of the reactor configuration on the plasma behavior and PECVD deposition. The two major PECVD reactor systems are reviewed, and then several new concepts are considered. 

This chapter deals exclusively with the methods that have been developed for the direct solids analysis of nonconductive samples by glow discharge mass spectrometry. The basic approaches to operation and sample preparation for the three primary methodologies of compaction, secondary cathode, and radio frequency powering are described. Examples of source performance and practical applications of each are taken from the analytical literature. Whereas this chapter de-... 

This paper basically represents a feasibility study of the deposition of boron from a glow discharge system produced in a boron trichloride-hydrogen medium. Feasibility of the basic concept has been conclusively... 

Fig. 1. Schematic diagram of a high-frequency glow-discharge reactor, and the electric potential between electrodes (Japan Society of Applied Physics, 1993). The left-hand panel shows the basic structure of the reactor. The right-hand panel shows the electric potential.

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