INSULATED ISOLATION TYPE SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To surely detect a defect in an insulated isolation trench even in the case wherein the insulated isolation trench is shared by adjacent elements to minimize the device size. SOLUTION: The insulated isolation trench 13 for element forming regions 12a, 12b provided on an SOI substrate 11 is formed in a plane layout form having a shared side part CS shared by the adjacent element forming regions 12a, 12b. A field region 15 surrounding the insulated isolation trench 13 is provided thereon with an electrode pad 16 electrically connected to the field region 15, an electrode pad 17 electrically connected to the element forming region 12a, and an electrode pad 19 electrically connected to buried polysilicon filled into the insulated isolation trench 13. When the insulated isolation structure is inspected, an inspecting voltage is applied between the electrode pad 17 and the electrode pads 16 and 19 wherein the level of the voltage being in accordance with the assured withstand voltage thereof.