114 results about "Electric-field screening" patented technology

The invention relates to the technical field of semiconductors, in particular to a trench type MOSFET device and a preparation method thereof. The trench type MOSFET device sequentially comprises a drain electrode, an n+ substrate, an n+ buffer layer, an n- drift layer, a CSL layer, a p+ buried layer, a p well, a p+ region, an n+ region, a gate medium, a polysilicon gate, a gate source isolation medium and a source electrode from bottom to top. An active region of the device is composed of two types of primitive cells with different structures, one type of primitive cell is an MOSFET conductive primitive cell A, and the other type of primitive cell is a primitive cell B for carrying out electric field shielding on the trench gate structure, and a p+ buried layer in the primitive cell B iselectrically communicated with the source electrode through a p+ region above the p+ buried layer; in the direction parallel to the paper surface, the same type of primitive cells are connected in parallel left and right, and in the depth direction perpendicular to the paper surface, the two types of primitive cells are alternately arranged to form a conductive and shielding area. Through orderedarrangement of the two types of primitive cells by a certain method, the trench gate can be shielded, and very fine primitive cell sizes can be obtained. The device structure and the preparation process are simple, and popularization and application are facilitated.