Methods of forming hemispherical grained silicon on a template on a semiconductor work object
AssigneeMicron Technology, Inc.
InventorsGuoqing Chen, James Pan
Life of this patent
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Abstract
The present invention provides a method of preparing a surface of a silicon wafer for formation of HSG structures. The method contemplates providing a wafer having at least one HSG template comprising polysilicon formed in BPSG, the HSG template being covered by silicon dioxide. The wafer is treated with a cleaning agent to clean the surface of the wafer. Next, the wafer is treated with a conditioning agent. The conditioning agent removes native oxide from the HSG template without excessively etching structural BPSG. Preferably, the conditioning agent also removes a thin layer of polysilicon on the HSG template. The wafer is then transferred to a process chamber for HSG formation.
Claims57
A method of preparing a surface of a wafer for formation of HSG structures, comprising:
- providing a wafer having at least one HSG template comprising polysilicon formed in a BPSG layer on the wafer;
- treating the wafer with a cleaning agent comprising a solution of sulfuric acid and an oxidant to clean the surface of the wafer;
- and
- treating the cleaned wafer, before HSG formation, with a conditioning agent comprising ammonium fluoride and phosphoric acid to condition the HSG template for HSG formation by removing a thin layer of the HSG template.
A method of preparing a surface of a semiconductor work object for formation of HSG structures, comprising:
- providing a work object having at least one HSG template;
- treating the work object with a cleaning agent to clean the surface of the wafer;
- and
- treating the cleaned work object, before HSG formation, with a conditioning agent comprising an aqueous solution having a pH of about 4.0 to about 7.5 to condition the HSG template for HSG formation by removing a thin layer of the HSG template.
A method of preparing a surface of a semiconductor work object for formation of HSG structures, comprising:
- providing a work object having at least one HSG template;
- treating the work object with a cleaning agent to clean the surface of the wafer;
- and
- treating the cleaned work object, before HSG formation, with a conditioning agent including a fluorine component to condition the HSG template for HSG formation by removing a thin layer of the HSG template.
A method of preparing a surface of a semiconductor work object for formation of HSG structures, comprising:
- providing a work object having at least one HSG template;
- treating the work object with a cleaning agent to clean the surface of the wafer;
- and
- treating the cleaned work object, before HSG formation, with a conditioning agent to etch the HSG template by removing a thin layer of the HSG template so that it maintains its integrity for HSG formation but does not over-etch other selected portions of the surface.
The method of claim 50 wherein the cleaning agent comprises H2SO4 with either H2O2 or O3.
A method of preparing a surface of a semiconductor work object for formation of HSG structures, comprising:
- providing a work object having at least one HSG template in the form of a container-type capacitor having sidewalls;
- treating the work object with a cleaning agent to clean the surface of the wafer;
- and
- treating the cleaned work object, before HSG formation, with a conditioning agent to condition the HSG template for HSG formation by removing a thin layer of the HSG template.
Dependencies are inferred from the claim text.