Replacement fin approach

Figure 5.2 Schematic of how the defect trapping technique used in the replacement fin approach traps dislocation defects against the sidewalls of trenches with high aspect ratios. Situation shown post-CMP and recess etch.

Studies from several institutions have shown that it is possible to set up a working III—V CMP process using proprietary slurries or homemade model slurries (Matovu et al., 2014 Hill et al., 2013 Ong et al., 2013 Baneijee, 2014). Adjustments to the slurry composition and appropriate pad choice allow the development of IE-V poUsh-ing processes that achieve low IE—V roughness post-CMP and/or can remove the 111—V overburden in a replacement fin design approach. A stable and reproducible III—V CMP process is needed to ensure the formation of El—V channel layers of... 

A good approach to this kind of problem is to begin by calculating the possible hydrocarbon formulas. First divide the molecular weight by 12 to fin d the maximutn number of carbons possible. Each carbon is equal in mass to 12 hydrogens, so the next step is to replace I C by 12 H, giving anotlior possible formula. 

For the office environment, the more common system used today is the variable-air-volume (VAV) system. This approach was originally developed as a cooling system, but with proper apphcation of control it will serve equally well for heating. In climates where there is need for extensive heating, perimeter treatment is required to replace the skin loss of the building structure. An old but reUable method is fin-tube radiation supplied with hot water to replace the skin loss. A system that is being seen with more regularity is in the form of perimeter air supply. Care should be taken with the apphcation of perimeter air systems to ensure that wall U-values are at least to the level of ASHRAE Standard 90.1. If this is not done, interior surface temperatures will be too low and the occupants in the vicinity will feel cold. 

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