Structure for shallow junction MOS circuits

摘要

A contact structure and method of fabrication for achieving shallow junction MOS integrated circuits. An insulator (23) such as phosphosilicate glass is deposited over the circuit and contact windows (24 and 25) opened therein. Fire polishing of the glass is eliminated so that the junctions can be made shallow and the sides of the windows remain steep. A layer of polycrystalline silicon (26) is deposited over the insulator and the contact windows so as to conformally coat the sides of the windows and the exposed semiconductor. A contact metal (28 and 29), such as aluminum, is deposited over the polycrystalline silicon. The metal tends to be essentially discontinuous over the steep sides of the windows, but the polycrystalline silicon layer has sufficiently low resistivity to provide adequate conduction in these areas.