Particle getters

King J. Qualification of Dow Coming Q3-6527 as a Particle Getter. Singer Report YS57A834 1985. 

Use of silicone gel particle getters for microcircuit packaging. In Proc. ISHM 1985. Application Note 0503, Pike Technologies, www.piketech.com. 

Use of Silicone Gel Particle Getters for Microcircuit Packaging, Proc. ISHM (1985)... 

In the lean-burn stage all exhaust components are oxidized by the platinum particles in the catalyst. In particular, NO is oxidized to NO2. The latter reacts with BaO getter to form Ba(N03)2- In the rich mode, which only lasts for seconds, the exhaust stream is deficient in oxygen, and reducing components such as CO, H2 and hydro-... 

The remaining vacuum pumps to be discussed in this chapter fall into a group which remove gas particles from systems by sorption effects such as adsorption, chemisorption/gettering and implantation. They tend to be used on systems where any contamination of the vacuum by pump fluids, lubricants, etc. must be avoided. However, those pumps that remove gas particles exclusively by temperature-dependent gas adsorption on molecular sieves or A1203 (adsorption pumps) will not be discussed. 

Chapter 3 also considered those entrapment pumps that remove gas particles by sorption effects such as gettering and implantation. The operating principles of sputter ion pumps were explained (Example 3.26) and some typical calculations performed (Examples 3.27-3.29). Aspects of the use of titanium sublimation pumps were dealt with (Examples 3.30-3.33). 

Fig. 5.6. Reactive sputter process for depositing the compound film AB. (a) Balance of reactive gas flow Qtot, which is partially gettered at the target (Qt) and at the substrate (Qc) and partially pumped by the vacuum pump (Qp). The fraction of the target surface At that is covered by the compound AB is 6>t. The fraction of the collecting area Ac covered is Gc. j is the sputter current density, (b) Definition of particle fluxes that alter the target and collecting area coverage fractions 6>t and 6>c (see text), (modified from [70])...

An important result of the present analytical study is the detection of S in Y-rich precipitates within the alloy. This observation supports the sulfur effect model", which proposes that reactive elements getter the S [16,17]. The presence of S reduces the surface energy of the metal and thereby promotes the formation of interfacial voids, as has been shown by Grabke ct al. [18]. Although no S-rich particles have been found in NiAl - 0.2 wt% Zr. it is possible that the Zr can lower the activity of S by solute - solute interaction. Further work is necessary in order to study the interaction between reactive elements and S. 

In many CVD processes, toxic, explosive, and corrosive materials are produced as one component of the vapor phase reaction co-product. In order to remove them prior to atmospheric venting, scrubbers are employed, which must be appropriate for the process used. For example, halides frequently are neutralized in a water scrubber. Carbon monoxide and hydrogen often are burnt. Arsine generally is removed by heating the exhaust gas in a cracking furnace. Charcoal canisters often are used to absorb vapor phase species. Sulfur has been employed to getter thallium. Very fine particle filters also are used to catch a diversity of solids entrained within the exhaust stream. 

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