The residual stress generated by thin-films processing influences the devices’ performance and reliability. In this work, an optical-based laser scan technique is used to evaluate the residual stress of thin films. The study focuses on the thin films, commonly used in micro-electromechanical systems (MEMS) device fabrication namely thermally grown silicon dioxide, low-pressure chemical vapour deposited (LPCVD) polysilicon, plasma-enhanced chemical vapour deposited (PECVD) silicon oxide and plasma-enhanced chemical vapour deposited (PECVD) silicon nitride. The radius of curvature (ROC) of the substrate and the thin film deposited substrate are measured using a 780 nm wavelength laser source. The change in ROC is then used to determine the film stress using Stoney’s equation. The input parameters in Stoney’s equation comprise the material properties and thickness of the substrate material, thickness of the film and change in ROC, and play a crucial role in deciding the accuracy of the stress value. In that regard, the material property of the silicon (100) substrate measured using the nanoindentation technique was found to be 222 GPa for 0.064 Poisson’s ratio. A different set of experiments was performed to accurately evaluate the thickness of the substrate, and thickness of thin films using surface profilometry. The residual stress obtained for thermally grown silicon dioxide (of 110 nm thickness) thin film was −327 MPa. The polysilicon thin film (of 500 nm thickness) deposited on the oxidized silicon substrate incorporates −122 MPa stress on the substrate. The silicon oxide thin film (of 450 nm thickness) and silicon nitride thin film (of 620 nm thickness) deposited using the PECVD technique were found to induce residual stress of −163 MPa and −632 MPa, respectively, on the substrate.