Various embodiments provide a method for forming a memory device, comprising forming a bottom electrode over a substrate, forming a phase change layer over the bottom electrode, wherein the forming the phase change layer comprises alternatingly depositing a first layer of phase change material and a second layer of phase change material to form a laminated structure, the first layer of phase change material being chemically different from the second layer of phase change material, and the first layer of phase change material being deposited with a first thickness less than a second thickness of the second layer of phase change material. The method also includes forming a top electrode over the phase change layer, and forming a sidewall barrier layer in contact with sidewalls of the phase change layer, wherein the first layer of phase change material is a doped chalcogenide material containing a metallic dopant element and the second layer of phase change material is an undoped chalcogenide material, wherein at least a first one of the first layer of phase change material in the laminated structure is deposited with a first dopant concentration, and at least a second one of the first layer of phase change material is deposited with a second dopant concentration different than the first dopant concentration, wherein the alternatingly depositing is performed such that a topmost one of the second layer of phase change material contacts the top electrode, and the first layer of phase change material in the laminated structure contacts the bottom electrode, and wherein the forming the sidewall barrier layer is performed such that a side surface of the sidewall barrier layer is in contact with a sidewall of the top electrode, and a bottom surface of the sidewall barrier layer is in contact with a top surface of the bottom electrode.