Semiconductor device and method for manufacturing the same
A semiconductor device which eliminates the need for high fillability through a simple process and a method for manufacturing the same. A high breakdown voltage lateral MOS transistor including a source region and a drain region is completed on a surface of a semiconductor substrate. A trench which surrounds the transistor when seen in a plan view is made in the surface of the semiconductor substrate. An insulating film is formed over the transistor and in the trench so as to cover the transistor and form an air-gap space in the trench. Contact holes which reach the source region and drain region of the transistor respectively are made in an interlayer insulating film.
1. A semiconductor device comprising:
a semiconductor substrate having a trench in a main surface thereof;
a device being formed over the main surface of the semiconductor substrate; and
an insulating film being formed over the device and in the trench so as to cover the device and form an air-gap space in the trench,
wherein a side surface of the trench on a same level of a bottom of the air-gap space directly contacts the semiconductor substrate.
2. A semiconductor device according to claim 1 wherein,
the device has a conductive portion, and
the insulating film has a hole which reaches the conductive portion.
3. A semiconductor device according to claim 1 , wherein the trench is formed so as to surround the device when seen in a plan view.