VERFAHREN ZUR HERSTELLUNG EINER VERTIKALEN LEISTUNGS-MOSFET-STRUKTUR.

摘要

A power MOSFET semiconductor structure is fabricated using the steps of depositing an epitaxial layer 12 of N conductivity type silicon on an underlying silicon substrate 10 of N conductivity type, forming a plurality of polycrystalline silicon electrodes 18 on the epitaxial layer 12, each electrode 18 being separated from the epitaxial layer 12 by a layer of insulating material 15; introducing P 30 and N 33 conductivity type impurities into the epitaxial layer 12 between the electrodes 18, the P type impurity 30 underlying the N type impurity 33; removing regions of the epitaxial layer 12 to form openings 21 in the epitaxial layer 12 between the electrodes 18, the removed regions 21 extending through the N type region 33 but not through the P type region 30; and depositing electrically conductive material 40 in the opening 23. The resulting semiconductor structure includes an N type substrate 10, an N type epitaxial layer 12, an opening 21 in the epitaxial layer 12 extending downward a selected distance, an upper N type region 33 surrounding the opening 21 and extending to the surface of the epitaxial layer 12, a lower P type region 30 which extends to the surface of the epitaxial layer 12 and everywhere separates the N type region 33 from epitaxial layer 12, an electrode 40 formed in the opening and extending to the upper surface of the epitaxial layer 12, and a second electrode 18 disposed above epitaxial layer 12 and separated from it by insulating material 15.