US 6,150,233 A · Semiconductor device and method of manufacturing the same

Abstract

An underlaid silicon oxide film (2) and a polycrystalline silicon film (5) are formed in this order on a surface (1S) of a silicon substrate (1). The polycrystalline silicon film (5) and the underlaid silicon oxide (2) are opened by anisotropic etching, to form a trench (21) extending to the inside of the semiconductor substrate (1). A silicon oxide film (11) formed by HDP-CVD is buried in the trench (21). A resist (41) is formed only on a surface of the silicon oxide film (11) in a device isolation region (20). The silicon oxide film (11) in an active region (30) is removed by dry etching with the resist (41) as a mask. After removing the resist (41), only the polycrystalline silicon film (5) is removed by dry etching. The underlaid oxide film (2) is removed by wet etching with hydrofluoric acid. By this method of manufacturing a semiconductor device, the surface of the semiconductor substrate and a trench-type device isolation are flattened effectively at low cost.

Claims7

Dependent claims

A method of manufacturing a semiconductor device, comprising:

a first step of forming a hardmask layer including at least one layer on a surface of a semiconductor substrate;
a second step of forming a trench serving as a device isolation region and an active region which is a region other than said device isolation region inside said semiconductor substrate by etching part of said semiconductor substrate from a predetermined region in a surface of said hardmask layer;
a third step of forming a dielectric by a film-formation method in which an etching and a deposition are simultaneously performed on said surface of said hardmask layer and in said trench to bury said dielectric in said trench to the same level as said surface of said hardmask layer;
a fourth step of forming a resist on a surface of said dielectric at least in said device isolation region;
a fifth step of removing all of said dielectric on said active region with said resist as a mask, said dielectric is not covered with said resist;
and
a sixth step of removing said resist and said hardmask layer in this order.

4 more elements

A method of manufacturing a semiconductor device, comprising:

a first step of forming a hardmask layer including at least one layer on a surface of a semiconductor substrate;
a second step of forming a trench serving as a device isolation region and an active region which is a region other than said device isolation region inside said semiconductor substrate by etching part of said semiconductor substrate from a predetermined region in a surface of said hardmask layer;
a third step of forming a dielectric by a film-formation method in which an etching and a deposition are simultaneously performed on said surface of said hardmask layer and in said trench to bury said dielectric in said trench to the same level as said surface of said hardmask layer;
a fourth step of forming a resist on a surface of said dielectric at least in said device isolation region;
a fifth step of removing said dielectric on said active region with said resist as a mask, said dielectric is not covered with said resist;
and
a sixth step of removing said resist and said hardmask layer in this order, wherein said fourth step comprises the step of forming said resist on said dielectric in said active region so that said resist extends by a length corresponding to an alignment margin from an end portion of said device isolation region towards said active region;
and
said sixth step comprises the step of etching said dielectric with hydrofluoric acid before removing said hardmask layer after removing said resist.

6 more elements

Dependencies are inferred from the claim text.

Semiconductor device and method of manufacturing the same

Life of this patent

Semiconductor device and method of manufacturing the same

Life of this patent

Abstract

Claims7