US 2004/0185646 A1Published application

Method for creating a stepped structure on a substrate

AssigneeInfineon Technologies AG

InventorChristian Herzum

Life of this patent

Estimating the term…

Loading patent…

Abstract

In a method for creating a stepped structure on a substrate, which at least includes a first portion with a first thickness and a second portion with a second thickness, at first a layer sequence of a first oxide layer, a first nitride layer, and a second oxide layer is applied onto the substrate. Then a portion of the second oxide layer and a portion of the first nitride layer are removed to expose a portion of the first oxide layer. Then a part of the first nitride layer is removed to establish the first region of the stepped structure. Then the thickness of the first oxide layer is changed at least in the established first region to establish the first thickness of this region. Subsequently, a further part of the first nitride layer is removed to establish a second region of the stepped structure.

Claims17

Dependent claims

Method for creating a stepped structure on a substrate, wherein the stepped structure includes at least a first portion with a first thickness and a second portion with a second thickness, comprising:

(a) applying a layer sequence of a first oxide layer, a first nitride layer, and a second oxide layer to the substrate;
(b) removing a portion of the second oxide layer and a portion of the first nitride layer to expose a portion of the first oxide layer;
(c) removing a part of the first nitride layer above the first oxide layer and below the second oxide layer to establish the first region of the stepped structure;
(d) changing the thickness of the first oxide layer at least in the first region established in step (c) to establish the first thickness thereof;
and
(e) removing a part of the first nitride layer above the first oxide layer and below the second oxide layer to establish the second region of the stepped structure.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/750,405Filed 31 Dec 2003
Priority: DE 10131917.72 Jul 2001
Published: 23 Sep 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H10D 64/01344
On single crystalline silicon, e.g. chemical oxidation using a liquid: in a nitrogen-containing ambient, e.g. N2O oxidation
H10D 64/516
Characterised by the insulating layers: the thicknesses being non-uniform
H10D 64/685
Having a compositional variation, e.g. multilayered: being perpendicular to the channel plane
H10D 64/693
Characterised by the insulator, e.g. by the gate insulator: the insulator comprising nitrogen, e.g. nitrides, oxynitrides or nitrogen-doped materials