SOI device with a buried insulating material having increased etch resistivity
AssigneeAdvanced Micro Devices, Inc.
InventorsAndreas Kurz, Roman Boschke, Christoph Schwan, John Morgan
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Abstract
In SOI devices, the PN junction of circuit elements, such as substrate diodes, is formed in the substrate material on the basis of the buried insulating material that provides increased etch resistivity during wet chemical cleaning and etch processes. Consequently, undue exposure of the PN junction formed in the vicinity of the sidewalls of the buried insulating material may be avoided, which may cause reliability concerns in conventional SOI devices comprising a silicon dioxide material as the buried insulating layer.
Claims20
A method of forming a semiconductor device, the method comprising:
- providing a buried insulating material formed above a crystalline substrate material at least in a first device region, said buried insulating material having an increased etch resistivity as compared to silicon dioxide formed by an oxidation process with respect to a wet chemical cleaning recipe to be performed prior to forming a metal silicide in said crystalline substrate material and a semiconductor layer formed above said crystalline substrate material in at least a second device region;
- forming an opening through said buried insulating material in said first device region so as to expose a portion of said crystalline substrate material;
- forming drain and source regions of a transistor in said semiconductor layer in said second device region and a doped region in said crystalline substrate material exposed by said opening in a common implantation process;
- performing one or more cleaning processes on the basis of said wet chemical cleaning recipe;
- and
- forming said metal silicide in said transistor and said doped region.
A method, comprising:
- forming a buried insulating layer so as to have at least locally a higher etch resistivity than silicon dioxide with respect to a wet chemical etch process;
- treating a surface portion of a crystalline substrate material of a semiconductor device by performing said wet chemical process, said surface portion being exposed by an opening extending through said insulating layer to said crystalline substrate material;
- using at least a portion of said buried insulating layer as an etch protection material during said wet chemical process so as to maintain a width of said opening at least at a bottom thereof within a predefined range;
- and
- forming a metal silicide in said exposed portion of the crystalline substrate material.
Dependencies are inferred from the claim text.