A Premetal BPSG Filled Deep Trench Isolation Technology for ECL-BiCMOS LSIs using CMP

A newly developed BPSG filled deep trench isolation technology featuring trench formation at the end of the front end process is presented. A thick BPSG film is used as a trench filling material and interlayer dielectrics under-first level metal simultaneously. The process step counts in deep trench isolation process module is 70% smaller than that of a conventional process. The thick BPSG planarized interlayer dielectrics film can reduce the wiring capacitance and provides a fine pitch interconnection for scaled CMOS. Using this technology, a high performance/low cost ECL-BiCMOS LSI is achieved.