METAL-OXIDE-SEMICONDUCTOR FIELD-EFFECT TRANSISTOR

• Main Authors: YAMASHITA, Yusuke, TSUJIMURA, Masatoshi, URAKAMI, Yasushi, KINPARA, Hiromichi, ARAUCHI, Takuji
• Format: Patent
• Language: English; French; German
• Published: 29.08.2018
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A silicon carbide trench gate MOSFET device comprising a region (42) includes a high-concentration region (42a) and a low-concentration region (42b) that are arranged along a thickness direction of a silicon carbide substrate. A concentration of a p-type dopant in the low-concentration region (42b) is lower than a concentration of the p-type dopant in the high-concentration region (42a). The high-concentration region (42a) contacts the low-concentration region (42b), and is disposed between a bottom surface (13b) of a gate trench (13) and the low-concentration region (42b). In graph obtained by plotting the concentration of the p-type dopant in the floating region (42) along the thickness direction, a bending point or an inflection point appears on a boundary between the high-concentration region (42a) and the low-concentration region (42b). A content of the p-type dopant in the low-concentration region (42b) is equal to or higher than a content of an n-type dopant in a portion of the drift region (34), which is adjacent to the low-concentration region (42b) in the thickness direction.