A method of manufacturing a semiconductor device comprising forming an active region in a device substrate using a first phase shift mask (PSM) having a first patterned light shielding layer formed thereon, forming a polysilicon feature on the device substrate over the active region using a second PSM having a second patterned light shielding layer formed thereon, forming a contact feature on the polysilicon feature using a third PSM having a third patterned light shielding layer formed thereon, and forming a metal feature on the contact feature using a fourth PSM having a fourth patterned light shielding layer formed thereon, wherein at least one of the third and fourth patterned light shielding layers is patterned substantially similarly to at least one of the first and second patterned light shielding layers.