Using "reasonable" number e$.$g$.$ chip area $=2$ cm$^2$ and defect density ranging from $0\mathrm{.}001$ to $10/$cm$^2,$ plot how you would expect the cost per chip $($relative to $100\%$ yield$)$ to vary with defect density. Using your plot, comment on the effect of defect density reduction when the yield is $($a$)$ less than $20\%,($b$)$ over $80\%($ where do you get the most "bang for the buck"?$)$

Success hint: Don't just plot yield vs$.$ defect density, plot cost vs$.$ defect density. Assume the cost is$,$ for example,

$$1$ per chip at $100\%$ yield, and plot how this changes as the defect density increases.