In the case of differential geometry, the radius of curvature or R is the reciprocal of the curvature. For a given curve, it is equal to the radius of circular arc that perfectly approximates the curve at a particular point.

For surfaces, the radius of curvature is given as radius of circle that best fits the normal section or combination thereof. The major applications of the concept can be seen in differential geometry, to measure the radius of curvature of earth or bending of beams in a three-part equation. It is also used in optics as well.

The concept can be understood better by studying stress in semiconductor structures that usually involves the evaporation of thin films results from thermal expansion. This stress happens because film depositions are usually made up of the room temperature. When temperature is cool down to the room temperature then the difference in thermal expansion coefficients of substances will cause the stress.

The intrinsic stress results due to microstructure created in films as atoms and deposited on

\[\large R=\frac{(1+(\frac{dy}{dx})^{2})^{3}}{|\frac{d^{2}y}{dx}|}\]

Also, the radii of curvature can be measured through the optical scanner methods. There are modern scanner tools as well that are used to measure the full topography of