Renesas Electronics Corporation

Yoshitaka Otsu

Katsumi Morii

Tetsuya Nitta

Kazuma Onishi

Shinichiro Yanagi

Hiroshi Kimura

Shigeo Tokumitsu

Tatsuya Shiromoto

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.

Semiconductor device and method for manufacturing the same

There is formed a first concave portion that extends inside a semiconductor substrate from a main surface thereof. An insulating film is formed over the main surface, over a side wall and a bottom wall of the first concave portion so as to cover an element and to form a capped hollow in the first concave portion. A first hole portion is formed in the insulating film so as to reach the hollow in the first concave portion from an upper surface of the insulating film, and to reach the semiconductor substrate on the bottom wall of the first concave portion while leaving the insulating film over the side wall of the first concave portion. There is formed a second hole portion that reaches the conductive portion from the upper surface of the insulating film. The first and second hole portions are formed by the same etching treatment.

To provide a semiconductor device that can be manufactured using a simple process without ensuring a high embedding property; and a manufacturing method of the device. In the manufacturing method of the semiconductor device according to the invention, a semiconductor substrate having a configuration obtained by stacking a support substrate, a buried insulating film, and a semiconductor layer in order of mention is prepared first. Then, an element having a conductive portion is completed over the main surface of the semiconductor layer. A trench encompassing the element in a planar view and reaching the buried insulating film from the main surface of the semiconductor layer is formed. A first insulating film (interlayer insulating film) is formed over the element and in the trench to cover the element and form an air gap in the trench, respectively. Then, a contact hole reaching the conductive portion of the element is formed in the first insulating film.

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Hitachinaka, Japan

Yoshitaka Otsu