Equation 9 · Part 7 · Patterning at the Limit: What Actually Happens When a Chip Is Manufactured
Denominator: NA^2
What this part means
The complete quantity below the fraction bar; it must be nonzero for this division.
Its job in the formula
N occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.
Full expression→Denominator: NA^2→Article meaning
The passage around this formula
The relation that is usually left out of popular accounts is the one that costs money: . Depth of focus falls with the square of numerical aperture. Resolution is bought linearly in and paid for quadratically in focus budget. This is why the planarisation step exists at all, why resist films keep getting thinner, and why every increase in makes the mechanical and material problems worse rather than better. The roadmap is explicit that meeting small depths of focus at 0.55 numerical aperture is a key challenge in its own right, and that a longer-term move to still higher aperture would drive resist thicknesses below 20 nm [ 1 ] .
Learn the underlying idea
A fraction a/b means a divided by b. The top number is the numerator; the bottom number is the denominator, and it cannot be zero.
Open the illustrated fractions: division written vertically guide →
Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.