If N is the doping level of substrate and V is the effective voltage across the junction in a MOSFET, then the depletion region width for the junction is given by:
1
\(\rm\sqrt{\frac{2 \epsilon_{st} \epsilon_0 V}{q N}}\)
2
\(\rm\sqrt{\frac{2 \epsilon_{st} \epsilon_{0}qv}{N}}\)
3
\(\rm\sqrt{\frac{2 \epsilon_{st} N}{qV}}\)
4
\(\rm\frac{2 \epsilon_{st} \epsilon_0 V}{q N}\)