A vehicle and method of operation having a first door, a second door, an inflatable door seal assembly and an inflator assembly. The bumper is retained in the receptacle by a number of spaced ribs that engage certain portions of the bumper yet permit deformations of other portions of the bumper into an expansion region. The PSZ film deposited on the mask member is removed, leaving part of the PSZ film inside the trench, wherein the thickness of the PSZ film is controlled to make the height thereof from the bottom of the STI trench become 600 nm or less.