A light emitting device and method of forming the same, the light emitting device including: a substrate, a buffer layer disposed on the substrate, a semiconductor mesa disposed on the buffer layer and including a first semiconductor layer, a light emitting active layer disposed on the first semiconductor layer, and a second semiconductor layer disposed on the first semiconductor layer, a contact layer disposed on an upper surface of the mesa, a passivation layer covering sidewalls of the mesa and the contact layer, and a cap structure including a reflective layer covering an upper surface of the contact layer, and a solder layer including a recess in which the reflective layer is disposed.