Sputtering description

A discussion of the motivation behind doing sputtered neutral analysis versus SIMS, plus a description of the first prototype SALI instrument. A well written introduction for someone without previous surface analysis experience it also includes an historical overview of the various post-ionization techniques. 

Chemical vapor deposition competes directly with other coating processes which, in many cases, are more suitable for the application under consideration. These competing processes comprise the physical vapor deposition (PVD) processes of evaporation, sputtering, and ion plating, as well as the molten-material process of thermal spray and the liquid-phase process of solgel. A short description of each process follows. For greater detail, the listed references should be consulted. 

In this chapter we describe briefly the physical phenomena, such as sputtering, scattering, neutralization and reionization, that are involved in ion spectroscopy. For a detailed description of the interactions of ions with solids we refer to the books by Feldman and Mayer [1], Benninghoven, Riidenauer and Werner [2], and Czandema and Hercules [3]. 

The problem that remains is the study of the interaction of a shock with a matrix of holes in three-dimensional geometry. The basic two-dimensional processes involved in the failure of detonation, the failure diameter of explosives, and the sputtering initiation observed for density discontinuities near the critical size have been described. The three-dimensional study of the interaction of numerous failures and reignited detonations which is necessary for a complete numerical description of these problems must await new computing hardware ... 

Despite recent promising strategies, the principle of micro-process engineering is still not widely used in combinatorial catalysis. One drawback certainly is the increasing distance from industrial applications with decreasing dimensions. However, the small structures possess laminar flow conditions that are fully accessible by analytical as well as numerical macroscopic descriptions. This offers the chance to describe thoroughly the fluidic, diffusive and reactive phenomena in catalysis to find intrinsic kinetics on using, for example, non-porous sputtered catalysts. 

Detailed description of all mentioned material processing tools can be found in special literature and handbooks2 [7-11]. In this chapter, only the most popular method of composite production the method of a material sputtering on a substrate [4,27] - will be discussed. 

Similar to the temperature dependence also the energy dependence of chemical sputtering can be reproduced adequately using the analytic description. 

Furthermore the system is fully automated, self-tuning and needs little or no maintenance. The operator will consider the instmment as an analytic tool the fact that an accelerator is involved is incidental. Up to 50 solid graphite samples can be loaded in a carousel prior to analysis. COj samples can be admitted on line to the ion source. The ion source uses a primary caesium beam to sputter the sample under investigation to form a negative carbon ion beam. The ion beam is accelerated through the system to reach the detector with an energy of 2.5 MeV. A detailed description of the system can be found in Nucl. Instr. and Meth. B123 (1997) 159. 

In a description of sputtering from a multicomponent system, the influence of preferential sputtering and surface segregation must be included. For a homogeneous sample with atomic components A and B, and in the absence of surface segregation, the surface concentration, IVs, is equal to that in the bulk, Nb. Therefore, at the start of sputtering... 

Sputter-depth profiling is the most frequently used technique and is ideal especially for thin-film analysis. In a review paper by GOnther [88] on Non optical characterization of optical coatings , one of the topics is depth profiling. The following descriptions on sputter profiling are taken partly from this review. 

The basic parameter in the description of sputtering is the sputter yield, S, defined as the average number of atoms (neu-... 

As described above, even though there are many types of dry processes, univer-salistic dry processes are restricted to certain ones at this point vacuum deposition, sputtering and ion plating (examples of the PVD process) and many kinds of CVD processes. General descriptions of them are provided. 

Trilayer PPy actuators were first reported by the Intelligent Polymer Research Institute at the University of Wollongong, Australia. A description of the fabrication process can be found in, e.g., [Wu et al. (2006)], and it is provided here for completeness. The PPy layers are electrochemically deposited on both sides of a gold-coated porous PVDF film. The PVDF film obtained from Sigma-Aldrich Co., has a thickness of 110 lam with pore size of 0.45 /Ltm. Gold layers of 100 nm are sputtered on both sides of the PVDF,... 

On the basis of this model, a mathematical description was devised that is able to consistently describe all experimental observations, which can be extrapolated to other projectiles. In particular, the model correctly reproduces experimentally observed isotope dependence for bombardment with H and D and allows extrapolation to tritium (Hopf and Jacob 2005). The chemical sputtering yield of carbon due to bombardment with D is about a factor of 2 higher than that of H. Due to the higher mass of tritium, the predicted chemical sputtering yield of tritium will be about 50% higher than that for deuterium (Hopf and Jacob 2005). 

---