A method of fabricating a semiconductor device may include forming a first conductive layer on first to third regions of a substrate, forming a barrier layer on the first conductive layer, the barrier layer including a first barrier layer, a second barrier layer, and a sacrificial layer which are sequentially formed, sequentially forming a second conductive layer and a third conductive layer on the barrier layer, performing a first etching process to remove the third conductive layer from the second region and the third region, the third conductive layer remaining on the first region after the first etching process, and performing a second etching process to remove the second conductive layer and the sacrificial layer from the third region, the second conductive layer and the sacrificial layer remaining on the first region and on the second region after the second etching process.