An engineer is specifying a silicon dioxide thickness to use as an etch mask for a $\backslash (42\backslash \%\backslash$mathrm$\{$KOH$\}\backslash )$ etch on a $(100)$ silicon wafer. The etching temperature is $\backslash (80^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ),$ and the desired etching depth is $\backslash (400\backslash$mu $\backslash$mathrm$\{$~m$\}\backslash ).$ Calculate the required silicon dioxide thickness for these etch conditions. If the engineer wants to have $2000$ Angstroms of silicon dioxide remaining after the etch, what oxidation time should be used for an $\backslash (1100^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash )$ wet oxidation? Assume a $25$ Angstrom native oxide thickness. An evaporator is used to deposit aluminum. The aluminum charge is maintained at a uniform temperature of $\backslash (1100^\{\backslash$circ$\}\backslash$mathrm$\{$C$\}\backslash ).$ If the evaporator planetary has a radius of $40$ cm and the diameter of the crucible is $5$ cm $,$ what is the deposition rate of aluminum? Clearly state all assumptions.