SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

• Main Authors: UMEMURA NOBUAKI, ARIE HIROYUKI, HATTORI NOBUYOSHI, HARA KIMIO, ISHIKAWA MAKOTO, NITTA KYOYA, NAKANISHI NOBUTO
• Format: Patent
• Language: English
• Published: 30.12.2010
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

In a semiconductor device having an LDMOSFET, a source electrode is at the back surface thereof. Therefore, to reduce electric resistance between a source contact region in the top surface and the source electrode at the back surface, a poly-silicon buried plug is provided which extends from the upper surface into a P+-type substrate through a P-type epitaxial layer, and is heavily doped with boron. Dislocation occurs in a mono-crystalline silicon region around the poly-silicon buried plug to induce a leakage failure. The semiconductor device has a silicon-based plug extending through the boundary surface between first and second semiconductor layers having different impurity concentrations. At least the inside of the plug is a poly-crystalline region. Of the surface of the poly-crystalline region, the portions located on both sides of the foregoing boundary surface in adjacent relation thereto are each covered with a solid-phase epitaxial region.