Global Potential Control Technique Used in Isolation Structure for 1200V HVICs

The global potential control technique regards the potential distribution of each part in the 1200V isolation structure as interacting. The potential distribution of high voltage junction termination (HVJT) is extracted by the potential delivering field plates (PDFPs) with uniform arrangement, and a new potential distribution is formed with the change of PDFPs' spacing on the P-isolation ring region. When the PDFPs are extended to the P/N-channel lateral diffused metal-oxide-semiconductor (P/NLDMOS), the spacing is widened near the source/drain side and is narrowed on the middled drift region. The potential distributions of LDMOS are redistributed by the PDFPs, which suppresses the premature leakage effectively. The breakdown voltage (BV) of the isolation structure has a 364% improvement, even though the doping concentration of the P-drift is taken to a very high value.