Structure of interlayer insulator film and method for planarization of interlayer insulator film
AssigneeNEC Corporation
InventorSatoru Sugiyama
Life of this patent
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Abstract
An interlayer insulator film in a semiconductor device comprises a BPSG film formed to cover a circuit pattern formed on a semiconductor substrate, and a ladder structure SOG film having a ladder structure in a molecular structure, to cover the BPSG film. The ladder structure SOG /film is etched back by a dry etching to partially expose the BPSG film, /and an exposed portion of the BPSG film is selectively etched by a wet /etching of a buffered HF using the remaining SOG film as a mask, since a /selective etching ratio by the buffered HF between the ladder structure /SOG film and the BPSG film is large. Thus, a planarized interlayer /insulator film formed of the remaining BPSG film and the remaining /ladder structure SOG film is obtained.
Claims10
A method for forming an interlayer insulator film in a semiconductor device, comprising the steps of:
- forming a silicon oxide film to cover a circuit pattern formed on a semiconductor substrate;
- forming a spin-on-glass film having a ladder structure in a molecular structure to cover said silicon oxide film;
- etching back said spin-on-glass film to partially expose said silicon oxide film;
- and
- selectively etching an exposed portion of said silicon oxide film by a wet etching using the remaining spin-on-glass film as a mask, so that a planarized interlayer insulator film formed of the remaining silicon oxide film and said remaining spin-on-glass film is obtained.
Dependencies are inferred from the claim text.