Trench DRAM semiconductor memory has additional p-type anti-punch zone in semiconductor under neighboring strips of shallow trench isolation

摘要

A trench DRAM semiconductor memory comprises a cell field (1) with parallel strips (2) of memory cells mutually insulated by shallow trench isolation (19) with neighboring cells along a strip also mutually isolated. A p-trench zone (11) in a semiconductor body (10) has an n-channel transistor per cell with source/drain connections to a bitline and through a buried strip to an electrode of a trench memory capacitor. A p-type anti-punch zone (23') lies in the trench beneath the bitline. An independent claim is also included for the production of an anti-punch zone for the above.