Semiconductor device and method of manufacturing semiconductor device

Abstract

A semiconductor device includes a semiconductor chip that has a first principal surface and a second principal surface located on a side opposite to a side of the first principal surface and an element isolation portion that is formed on the side of the first principal surface of the semiconductor chip and that demarcates an active region. The element isolation portion includes a trench formed on the side of the first principal surface of the semiconductor chip, a first insulating film formed on a side surface of the trench, a second insulating film formed inside the trench inwardly from the first insulating film with an air gap between the first insulating film and the second insulating film, and a buried conductor that is covered by the second insulating film and that is connected to the semiconductor chip at a bottom portion of the trench.

Dependencies are inferred from the claim text.