Electron beam sputtering technique

Techniques that can be destructive to the electrode s surfaces, such as SIMS, XPS, and AES (the X-ray beam, argon ions during sputtering), and Raman (the laser beam), AFM (in contact mode), SEM (the electron beam) vs. techniques such as FTIR spectroscopy, which is not destructive. 

Auger electron spectroscopy (AES) is a technique used to identify the elemental composition, and in many cases, the chemical bonding of the atoms in the surface region of solid samples. It can be combined with ion-beam sputtering to remove material from the surface and to continue to monitor the composition and chemistry of the remaining surface as this surface moves into the sample. It uses an electron beam as a probe of the sample surface and its output is the energy distribution of the secondary electrons released by the probe beam from the sample, although only the Ai er electron component of the secondaries is used in the analysis. 

Chemical alternation of the surface layer and deposition of a new layer on top of the silicone mbber can be achieved by physical techniques. For the inert surface of silicone rubber, the former requires the generation of high-energy species, such as radicals, ions, or molecules in excited electronic states. In the latter case, coatings of atoms or atomic clusters are deposited on polymer surfaces using technique such as plasma (sputtering and plasma polymerization) or energy-induced sublimation, like thermal or electron beam-induced evaporation. 

Some physical techniques can be classified into flame treatments, corona treatments, cold plasma treatments, ultraviolet (UV) treatment, laser treatments, x-ray treatments, electron-beam treatments, ion-beam treatments, and metallization and sputtering, in which corona, plasma, and laser treatments are the most commonly used methods to modify silicone polymers. In the presence of oxygen, high-energy-photon treatment induces the formation of radical sites at surfaces these sites then react with atmospheric oxygen forming oxygenated functions. 

Sputtering- Deposition of copper doped (damascene) almninum interconnects, as well as diffusion barriers, and anti-reflective stacks of Ti/TiN is done by this technique. The metal is heated by an electron beam and "sputters" onto the target. Nitrogen gas is used when TiN is required. 

This technique can be applied to samples prepared for study by scanning electron microscopy (SEM). When subject to impact by electrons, atoms emit characteristic X-ray line spectra, which are almost completely independent of the physical or chemical state of the specimen (Reed, 1973). To analyse samples, they are prepared as required for SEM, that is they are mounted on an appropriate holder, sputter coated to provide an electrically conductive surface, generally using gold, and then examined under high vacuum. The electron beam is focussed to impinge upon a selected spot on the surface of the specimen and the resulting X-ray spectrum is analysed. 

Since ion beams (like electron beams) can be readily focussed and deflected on a sample so that chemical composition imaging is possible. The sputtered particles largely originate from the top one or two atom layers of a surface, so that SIMS is a surface specific technique and it provides information on a depth scale comparable with other surface spectroscopies. 

Other coating processes involving fluoridated apatite have been investigated to improve the long-term adhesion and promote osteointegration of cementless titanium-based metal implants pulsed laser deposition, electron beam deposition and ion beam sputter deposition techniques, and sol-gel methods, for example. They lead to fluor-containing calcium phosphates (apatites in most cases) with different compositions and crystallinity states. 

In SIMSLAB from VG Scientific, both surface analytical techniques - SIMS and SNMS - have been applied (see Figure 5.34). In this mass spectrometer different types of primary ion sources are available. Ar+, Cs+, Ga+ or O) primary ions are accelerated in the secondary ion source on the solid sample surface. Similar to the CAMECA IMS-7f, with this experimental arrangement, besides depth profiling, a microlocal analysis can also be performed. The sputtered secondary ions (for SIMS) or the post-ionized sputtered neutrals (for SNMS) - the post-ionization is carried out by an electron beam in an ionizer box (right-hand schematic in Figure 5.34) - are separated... 

Vacuum deposition techniques, such as sputtering, electron beam evaporation, and plasma deposition are common. Photopolymerization and laser-assisted depositions are used for preparation of specialized layers, particularly in the fabrication of sensing arrays. Most commercial instruments have thickness monitors (Chapter 4) that allow precise control of the deposition process. 

The most widely used vacuum deposition techniques are evaporation and sputtering, often employed for smaller substrates. In the evaporation process, heating the metal by an electron beam or by direct resistance produces the vapours. The system is operated at a very high vacuum (between 10-5 and 10 6 Torr) to allow a free path for the evaporant to reach the substrate. The rate of metal deposition by evaporation processes varies from 100 to 250,000 A min h These processes can be operated on a batch or a continuous scale. On the other hand, in the case of the sputtering technique, the reaction chamber is first evacuated to a pressure of about 10-5 Torr and then back-filled with an inert gas up to a pressure of 100 mTorr. A strong electric field in the chamber renders ionisation of the inert gas. These inert gas ions... 

The closely allied topics of secondary neutral mass spectrometry (SNMS), fast atom bombardment (FAB), and laser ablation SIMS are important, but are beyond the scope of this chapter. SNMS is a technique in which neutral atoms or molecules, sputtered by an ion beam, are ionized in an effort to improve sensitivity and to decouple ion formation from matrix chemical properties, making quantification easier. This ionization is commonly effected by electron beams or lasers. FAB uses a neutral atom beam to create ions on the surface. It is often useful for insulator analysis. Laser ablation creates ions in either resonant or nonresonant modes and can be quite sensitive and complex. 

Porous structure of the outer support surface has been modified by deposition of the additional layer of metal Ni. Two vacuum condensation techniques have been used for nickel deposition dc ion magnetron sputtering and electron beam evaporation. To produce coatings on tubes additional installation for dc sputtering has been designed. 

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