A semiconductor device and a method for manufacturing the same and method for
deleting
information in use of the semiconductor device, in which field shield isolation
or a trench type isolation between elements is used with suppression of penetration
of field oxide into element active region of the device, that is, a defect involved
in conventional LOCOS type process, are disclosed. A non-LOCOS insulating device
isolation block is formed in a semiconductor substrate. The non-LOCOS insulating
device isolation block uses a field shield element isolation structure or trench
type element isolation structure. After gate electrode wiring layers are formed
in a field region and an active region to the same level, a pad polysilicon film
formed on the entire surface to cover the patterns of these gate electrode wiring
layers is polished by chemical mechanical polishing (CMP) using the cap insulating
films of the gate electrode wiring layers as stoppers, thereby forming the gate
electrode wiring layers into separated patterns. With this arrangement, even when
the width of the gate electrode wiring layer is reduced to the exposure limit in
photolithography, the pad polysilicon film can be separated and patterned.
