Interference Lithography is a developing technique for producing micro/nano array pattern structures over large areas. This paper focus on generation of nano/micro feature size patterns using four-beam interference lithography technique. The generated periodic array pattern structures are developed using MATLAB. The interference parameters in FBIL include wavelength (λ), slit separation (d), angle of incidence (Θ), distance between slit and screen (L) and depth of penetration (DOP). We have simulated and modelled the four beam interference lithography technique by varying interference parameters to produce various feature size patterns over the surface of the substrate. The obtained pattern structures have the periodicity of 0.75 μm for 1064 nm, 0.39 μm for 565 nm. Depth of the focus is found to be 0.235 μm for 1064 nm and 0.125μm for 565 nm. Highest value of depth of penetration is observed to be 0.552 mm and 0.586 mm for 1064 nm and 565 nm respectively. The study of FBIL shows depth of penetration increases with decrease in slit separation. More complex patterns can also be produced on varying the position of beams, angle of incidence and number of beams. FBIL can be applied in fabrication of 3D photonic crystals, magnetic storage, solar cells, waveguides, calibration grids, OLEDs and functional surfaces of sensors. © 2015 IEEE.