From HDDGURU:HDD Low Level Format Tool is a freeware utility for low-level hard disk drive formatting. This small program will erase, Low-Level Format and re-certify a SATA, IDE or SCSI hard disk drive.
Will work with USB and FIREWIRE external drive enclosures. Low-level formatting of Flash Cards is supported too. Low Level Format Tool will clear partitions, MBR, and every bit of user data.