SEMICONDUCTOR STRUCTURE AND METHOD OF FORMING IT (SEMICONDUCTOR STRUCTURE WITH FIELD SHIELD AND METHOD OF FORMING THE STRUCTURE)

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor structure that incorporates a field shield below a semiconductor device (e.g., a field effect transistor (FET) or a diode).;SOLUTION: This field shield is sandwiched between upper and lower isolation layers 203, 204 on a wafer. A local interconnect 235 extends through the upper isolation layer 204 and connects the field shield to a selected doped semiconductor region of the device (e.g., a source/drain region 211, 212 of a FET or a cathode or anode of a diode). Current that passes into the device, for example, during back-end of the line charging, is shunted by the local interconnect away from the upper isolation layer 204 and down into the field shield. Consequently, an electric charge 220 is not allowed to build up in the upper isolation layer but rather bleeds from the field shield into the lower isolation layer and into the substrate below. This field shield further provides a protective barrier against any electric charge that becomes trapped within the lower isolation layer or substrate.;COPYRIGHT: (C)2008,JPO&INPIT