A method of forming a perpendicular magnetic recording medium. The perpendicular magnetic recording medium comprises a substrate, an underlayer on the substrate, an intermediate layer on the underlayer and a recording layer on the intermediate layer. The underlayer comprises a first soft underlayer, an antiferromagnetically coupled Ru layer on the first soft underlayer, a second soft underlayer on the antiferromagnetically coupled Ru layer, and an orientation control layer on the second soft underlayer, the method comprises applying a negative bias voltage to the substrate during formation of the underlayer.