A DUAL GATE OXIDE PROCESS WITH REDUCED THERMAL DISTRIBUTION OF THIN-GATE CHANNEL IMPLANT PROFILES DUE TO THICK-GATE OXIDE

摘要

ABSTRACTA DUAL GATE OXIDE PROCESS WITH REDUCED THERMAL DISTRIBUTION OF THIN-GATE CHANNEL IMPLANT PROFILES DUE TO THICK-GATE OXIDEA new method is provided for the creation of layers of gate oxide of different thicknesses. A substrate is provided, thesurface of the substrate is divided into a first surface regionover which a thick layer of gate oxide has to be created and asecond surface region over which a thin layer of gate oxide is tobe created. Thick gate-oxide implants are performed into thesurface of the substrate. A thick layer of gate oxide is createdover the surface of the substrate, the thick layer of gate oxideis successively patterned for thin gate-oxide implants,comprising thin gate-oxide n-well/p-well, threshold, punchthroughimplants, into the second surface region of the substrate. Thethick layer of gate oxide is removed from the second surfaceregion of the substrate. The (now contaminated) top layer of thethick layer of gate oxide is removed, a thin layer of gate oxideis grown. over the second surface region of the substrate.FIGURE 2i