Semiconductor device and manufacturing method thereof

摘要

An object of one embodiment of the present invention is to provide an antifuse which has low writing voltage. The antifuse is used for a memory element for a read only memory device. The antifuse includes a first conductive layer, an insulating layer, a semiconductor layer, and a second conductive layer. The insulating layer included in the antifuse is a silicon oxynitride layer formed by adding ammonia to a source gas. When hydrogen is contained in the layer at greater than or equal to 1.2×1021 atoms/cm3 and less than or equal to 3.4×1021 atoms/cm3 or nitrogen is contained in the layer at greater than or equal to 3.2×1020 atoms/cm3 and less than or equal to 2.2×1021 atoms/cm3, writing can be performed at low voltage.