Post-depositional processes

Thin films formed by atomistic deposition techniques are unique materials that seldom have handbook properties. Properties of these thin films depend on several factors (4), including substrate surface condition, the deposition process used, details of the deposition process and system geometry, details of film growth on the substrate surface, and post-deposition processing and reactions. For some appHcations, such as wear resistance, the mechanical properties of the substrate is important to the functionaHty of the thin film. In order to have reproducible film properties, each of these factors must be controUed. 

These trends in lithologic features of the sedimentary rock mass can be a consequence of both evolution of the surface environment of the planet and recycling and post-depositional processes. It has been argued (e.g., Mackenzie, 1975 Veizer, 1988) that both secular and cyclic evolutionary processes have played a role in generating the lithology-age distribution we see today. For the past 1.5-2.0 billion years, the Earth has been in a near present-day steady state, and the temporal distribution of rock types since then has been controlled primarily by... 

The post deposition processing parameters (curing temperature, time) have a profound impact on the thermal properties of polyimide thin films. It has been observed that, films cured at around 300°C for 1 hour exhibit markedly superior thermal stability as compared to those that were not cured." ° Cured PMDA-ODA... 

Phillips et al. (2001) discussed the central evidence on which the reduced model of the Archaean atmosphere is based. This evidence includes the composition of detrital gold grains, inferred detrital uraninite, inferred detrital pyrite, and inferred palaeosols, especially in the Witwaters-rand succession. In a careful detailed review. Philips et al. concluded that the geological evidence for a reducing atmosphere remains ambiguous. In particular, post-depositional processes may need far more examination. Phillips et al. pointed out that some of the mineralogical and field evidence can be interpreted as supporting an oxidized Archaean atmosphere. 

In terms of post-depositional processes leading to the generation of aeolianites, a better understanding of the rates of lithification away from zones of accelerated diagenesis is required. This will be aided by isotopic analyses of aeolianite cements (as opposed to whole rock samples) which are needed to provide information on the environmental conditions under which diagenesis occurred. 

Birkmire R. W. and McCandless B. E. (1991), Analysis of post-deposition processing for CdTe/CdS thin-film solar cells , Solar Cells 31, 527-535. 

Post-deposition processing and reactions - e.g. reaction of the film surface with the ambient, thermal or mechanical cycling, corrosion, interfacial degradation, deformation (e.g. burnishing, shot peening) of soft surfaces, overcoating ( topcoat ). 

In the extreme, the film material can completely react with the substrate, thus forming a film of the interphase material. This is usually an effect of high substrate temperature during deposition or post-deposition processing. For example, platinum on silicon can be completely reacted to form a platinum silicide electrode material on the silicon. 

Post-deposition processing to increase adhesion and stabilize the system. 

Shot peening (post-deposition processing) Densifying a ductile film by repeatedly striking it with hard balls, usually entrained in a high velocity gas stream. Peening compacts the film and closes porosity. 

This book covers all aspects of Physical Vapor Deposition (PVD) process technology from the characterizing and preparing the substrate material, through deposition processing and film characterization, to post deposition processing. The emphasis of the book is on the aspects of the process flow that are critical to reproducible deposition of films that have the desired properties. 

Carbonates are modified by various post-depositional processes such as dissolution, cementation, recrystallization, dolomitization, and replacement by other minerals. Dolomitization is associated with an increase of porosity. 

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