Method to form gate conductor structures of dual doped polysilicon

A method for manufacturing a semiconductor chip which has transistors is disclosed. The transistors include first type transistors which have a first type of doping and second type transistors which have a second type of doping different than the first type of doping. The method includes forming a conductive layer on a substrate. The conductive layer includes first regions that have the first type of doping and second regions have the second type of doping. The invention patterns a mask over the conductive layer, and the mask protects portions of the conductive layer where gate conductors will be located. Next, the invention partially etches unprotected portions of the conductive layer. The partially etching process allows a layer of the unprotected portions to remain, such that the substrate is not exposed by the partially etching process. The invention forms a passivating layer on exposed vertical surfaces of the conductive layer and completely etches unprotected portions of the conductive layer to expose the substrate. The invention then dopes exposed portions of the substrate to form source/drain regions.