Semiconductor Components Industries, LLC

Sanyo Semiconductor Manufacturing Co., Ltd.

Sanyo Semiconductor Co., Ltd.

Keita Odajima

Akira Suzuki

Katsuyuki Seki

Koujiro Kameyama

Kikuo Okada

A mesa type semiconductor device and its manufacturing method are offered to increase a withstand voltage as well as reducing a leakage current. An N-type semiconductor layer is formed on a surface of a semiconductor substrate, and a P-type semiconductor layer is formed on the N-type semiconductor layer. After that, a mesa groove is formed by etching the P-type semiconductor layer, a PN junction, the N-type semiconductor layer and a partial thickness of the semiconductor substrate so that a width of the mesa groove grows from a surface of the P-type semiconductor layer toward the semiconductor substrate. Subsequent wet etching removes a damaged layer in an inner wall of the mesa groove caused by the preceding etching and transforms the mesa groove in a region close to a surface of the P-type semiconductor layer so that a width of the mesa groove increases toward the surface of the P-type semiconductor layer. After that, the semiconductor substrate and the layers stacked on it are diced.

Mesa type semiconductor device

The invention provides a mesa semiconductor device and a method of manufacturing the same which enhance the yield and productivity. 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 anode electrode is further formed on the P type semiconductor layer so as to be connected to the P type semiconductor layer, and a mesa groove is formed from the front surface of the P type semiconductor layer deeper than the N&#x2212; type semiconductor layer so as to surround the anode electrode. Then, a second insulation film is formed from inside the mesa groove onto the P type semiconductor layer on the outside of the mesa groove. The second insulation film is made of an organic insulator such as polyimide type resin or the like. The lamination body made of the semiconductor substrate and the layers laminated thereon is then diced along a scribe line.

Mesa semiconductor device and method of manufacturing the same

The invention provides a mesa semiconductor device and a method of manufacturing the same which minimize the manufacturing cost and prevents contamination and physical damage of the device. 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 anode electrode is further formed on the P type semiconductor layer so as to be connected to the P type semiconductor layer, and a mesa groove is formed from the front surface of the P type semiconductor layer deeper than the N&#x2212; type semiconductor layer so as to surround the anode electrode. Then, a second insulation film is formed from inside the mesa groove onto the end portion of the anode electrode. The second insulation film is made of an organic insulator such as polyimide type resin or the like. The lamination body made of the semiconductor substrate and the layers laminated thereon is then diced along a scribe line.

This invention is directed to solving problems with a mesa type semiconductor device, which are deterioration in a withstand voltage and occurrence of a leakage current caused by reduced thickness of a second insulation film on an inner wall of a mesa groove corresponding to a PN junction, and offers a mesa type semiconductor device of high withstand voltage and high reliability and its manufacturing method. After the mesa groove is formed by dry-etching, wet-etching with an etching solution including hydrofluoric acid and nitric acid is further applied to a sidewall of the mesa groove to form an overhang made of the first insulation film above an upper portion of the mesa groove. The overhang serves as a barrier to prevent the second insulation film formed in the mesa groove and on the first insulation film around the mesa groove beyond an area of the overhang from flowing toward a bottom of the mesa groove due to an increased fluidity resulting from a subsequent thermal treatment. As a result, the inner wall of the mesa groove corresponding to the PN junction is covered with the second insulation film thick enough to secure a desired withstand voltage and to reduce a leakage current.

Growing community of inventors

Fukaya, Japan

Keita Odajima