Semiconductor Components Industries, LLC

Sanyo Semiconductor Co., Ltd.

Sanyo Semiconductor Manufacturing Co., Ltd.

Naofumi Tsuchiya

Akira Suzuki

Koujiro Kameyama

Kikuo Okada

Katsuyuki Seki

Problems with a conventional mesa type semiconductor device, which are deterioration in a withstand voltage and occurrence of a leakage current caused by reduced thickness of an insulation film on an inner wall of a mesa groove corresponding to a PN junction, are solved using an inexpensive material, and a mesa type semiconductor device of high withstand voltage and high reliability is offered together with its manufacturing method. A stable protection film made of a thermal oxide film is formed on the inner wall of the mesa groove in the mesa type semiconductor device to cover and protect the PN junction, and an insulation film having negative electric charges is formed to fill a space in the mesa groove covered with the thermal oxide film so that an electron accumulation layer is not easily formed at an interface between an Ntype semiconductor layer and the thermal oxide film. With the structure described above, an influence of the positive electric charges in the thermal oxide film is weakened and an extension of a depletion layer into the Ntype semiconductor layer at the interface with the thermal oxide film is secured.

Mesa type semiconductor device and manufacturing method thereof

The invention is directed to reduction of a manufacturing cost and enhancement of a breakdown voltage of a PN junction portion abutting on a guard ring. An N&#x2212; type semiconductor layer is formed on a front surface of a semiconductor substrate, and a P type semiconductor layer is formed thereon. An insulation film is formed on the P type semiconductor layer. Then, a plurality of grooves, i.e., a first groove, a second groove and a third groove are formed from the insulation film to the middle of the N&#x2212; type semiconductor layer in the thickness direction thereof. The plurality of grooves is formed so that one of the two grooves next to each other among these, that is closer to an electronic device, i.e., to an anode electrode, is formed shallower than the other located on the outside of the one. Then, an insulating material is deposited in the first groove, the second groove and the third groove. The lamination body of the semiconductor substrate and the layers laminated thereon is then diced along dicing lines.

Semiconductor device and method of manufacturing the same

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Ota, Japan

Naofumi Tsuchiya