A backlight unit includes a light guide plate, at least one lamp provided at one or both sides of the light guide plate, a lamp housing surrounding the lamp, a lamp reflection plate positioned under the light guide plate to reflect light emitted from the lamp towards the light guide plate, and a polarization layer on an upper surface of the light guide plate and having an embossed pattern of protrusions and grooves on an upper surface thereof. A method for forming the backlight unit and a liquid crystal display device comprising the same are also disclosed.