Effect of equivalent surface charge density on electrical field of positively beveled p-n junction

摘要

The space-charge layer(SCL)and surface depletion area(SDA)model for beveled p-n junction is presented.The surface space-charge density is calculated for depletion case of beveled p-n junction.Based on the finite difference method, the effect of the equivalent surface charge density on the surface depletion area for positively beveled p-n junction is also studied.Thyristors passivated with polyimide(PI)or polyester improved silicon paint(SP)are fabricated to verify the effect of equivalent surface charge on the peripheral surface of beveled p-n junction.The change of leakage current is sensitive to the surface charges.It indicates that the selection of passivation materials is a significant process to ensure the breakdown voltage capability of beveled devices.