Abstract: A new NI (nC charge islands) high voltage device structure based on E-SIMOX (epitaxy-the separation by implantation of oxygen) substrate is proposed. It is characterized by equidistant high concentration nC-regions on the top interface of the dielectric buried layer. Inversion holes caused by the vertical electric field (EV/ are located in the spacing of two neighboring nC-regions on the interface by the force from lateral electric field (EL/ and the compositive operation of Coulomb’s forces with the ionized donors in the undepleted nC-regions. This effectively enhances the electric field of dielectric buried layer (EI/ and increases breakdown voltage (VB/. An analytical model of the vertical interface electric field for the NI SOI is presented, and the analytical results are in good agreement with the 2D simulative results. EI = 568 V/μm and VB = 230 V of NI SOI are obtained by 2D simulation on a 0.375-μm-thick dielectric layer and 2-μm-thick top silicon layer. The device can be manufactured by using the standard CMOS process with addition of a mask for implanting arsenic to form NI. 2-μm silicon layer can be achieved by using epitaxy SIMOX technology (E-SIMOX).

Key words: E-SIMOX,  charge islands,  breakdown voltage,  interface charges,  ENDIF