Film thickness controlling

To properly understand CMP film thickness control, the CMP engineer should understand the sources of thickness variation and how they impact the total film thickness uniformity. Nonuniformity can be grouped in two categories—random variation and systematic variation. Examples of random variation include wafer-to-wafer (WTW), run-to-run (RTR), and some elements of within-wafer (WIW) variations. Elements of random variation add to the total thickness variation by their root mean square [19]... 

On the other hand, liquid phase deposition (LPD) has been demonstrated as a flexible wet chemical method for preparing metal oxide nanostructured films on electrode surfaces. By the LPD process, electroactive titanium dioxide (Ti02) films were prepared on graphite, glassy carbon and ITO. The electrochemical properties of such LPD Ti02 films were dependent upon the film thickness controlled by the deposition time. The LPD technique was easily combined with other techniques, e.g., seed-mediated growth, which could provide metal/metal oxide composite nanomaterials. Moreover, hybrid nanostructured films were facilely obtained by doping dyes, surfactants and other... 

Different sizes of films were formed. The samples were cut to measure film properties and to establish a film thickness control equation. The small-diameter films were used for the water vapor permeability (WVP) and puncture strength (PS) large ones for tensile strength and elongation at break (%) measurement. The volume of solution was added over PVC plates at volume constant using a thin layer chromatography spreader. The plates were placed on a leveled surface to achieve uniform films and dried at room condition (25 2°C and 58 3% HR) for 24 to 48 h. Films used for each property measurement were manufactured and stored under the same temperature but at different relative humidity conditions. 

Layered nanostructures can be deposited from the electrochemical environment by applying a time dependent voltage program to the working electrode (5) or by using a sequential deposition scheme such as electrochemical atomic layer epitaxy (EC-ALE) (6-10). In EC-ALE, a surface-limited electrochemical reaction, such as underpotential deposition (upd), is used to synthesize a binary compound by successive deposition of each element from its respective solution precursor. EC-ALE is an attractive electrosynthetic alternative to conventional deposition methods that is inexpensive, operates at ambient temperature and pressure and provides precise film thickness control. This technique promises to overcome many problems associated with other electrosynthetic approaches, such as the formation of highly polycrystalline deposits and interfacial interdiffusion. For example, we have recently used EC-ALE to fabricate stable semiconductor heterojunctions with extremely abrupt interfaces (11). 

For fixed growth conditions, the size of the crystalline facets on the growth face increases with film thickness, controlled by growth time, as shown schematically in Figure 5.2. For example, higher quality NC BDD films (lower NDC content) can... 

Most current applications of arc vapor deposition do not require stringent film thickness control. The amount of deposited film is determined by the process parameters, fixture configuration, and deposition time. Often the substrates to be coated are heated in the... 

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