Method of manufacturing a semiconductor structure for a MOS transistor

摘要

In a MOS transistor structure with a polysilicon layer overlying a gate oxide, the novelty is that: (a) the polysilicon layer (3) has interruptions and forms field plates (14) and a polysilicon layer in the active region; (b) an insulating oxide (4) is provided above the field plates (14) and in the interruptions; and, (c) in the active region, the polysilicon layer (3) is thickened by further polysilicon deposition (10) so that it is coplanar with the insulating oxide (4) above the field plates (14). Also claimed is a method of producing the above semiconductor structure by: (i) producing a gate oxide and a polysilicon layer (3) on a substrate; (ii) depositing and structuring a dielectric on the polysilicon layer to form an active region; (iii) producing spacers on the edges resulting from structuring and partially oxidising the polysilicon layer between the spacers; (iv) removing the spacers to expose underlying polysilicon which is isotropically removed; (v) depositing a conformal oxide layer (9) and subjecting it to a spacer etching operation which also removes the oxide produced in step (iii); and (vi) depositing silicon (10) in the active region up to the level of the adjacent oxide structure.