Semiconductor device and its manufacturing method

摘要

A semiconductor device comprises a semiconductor substrate; a trench formed in the semiconductor substrate or in a layer deposited on the semiconductor substrate; a first conductive layer deposited in the trench and having a recess in the top surface thereof; a buried layer which buries the recess of the first conductive layer and which is made of a material having a melting point lower than that of the first conductive layer; and a second conductive layer formed on the buried layer inside the trench and electrically connected to the first conductive layer.