公开(公告)号：EP1790005A1

公开(公告)日：2007-05-30

申请号：EP05781623.3

申请日：2005-09-02

申请人： Koninklijke Philips Electronics N.V.

发明人： VAN NOORT, Wibo Daniel ,  DEIXLER, Peter

IPC分类号： H01L21/763

CPC分类号： H01L21/743 ,  H01L21/763

摘要： Electrically isolated, deep trench isolation (DTI) structures, are formed in a wafer, and a portion of the DTI structures are converted to electrically connected structures to provide a shielding function, or to provide connection to deep buried layers. In one aspect, DTI structures include a polysilicon filling over a liner layer disposed on the inner surface of a deep trench, the polysilicon is removed by isotropic etching, and the deep trench is re-filled with a conductive material. Alternatively, the polysilicon filling remains and a contact is formed to provide an electrical connection to the polysilicon. In another aspect, a deep trench is disposed in the wafer such that a lower portion thereof is located within a deep buried layer, and after the polysilicon is removed, an anisotropic etch removes a portion of the deep trench liner from the bottom of the deep trench, thereby allowing a tungsten deposition to make electrical contact with the deep buried layer.