Method of fabricating self-aligned contact window

Claim 1

A method of fabricating a self-aligned contact window, wherein a substrate having at least a conductive structure thereon is provided, the method comprising: forming an undoped dielectric layer over the substrate; transforming only a portion of the undoped dielectric layer into a doped dielectric layer, wherein the portion is aligned over the conductive structure; and removing the doped dielectric layer to form a self-aligned contact window within the undoped dielectric layer that exposes the conductive structure.

Claim 2

A method of fabricating a self-aligned contact window, wherein a substrate having at least a conductive structure thereon is provided, the method comprising: forming an undoped dielectric layer over the substrate; transforming only a portion of the undoped dielectric layer into a doped dielectric layer, wherein the portion is aligned over the conductive structure; and removing the doped dielectric layer to form a self-aligned contact window within the undoped dielectric layer that exposes the conductive structure.

Claim 7

A method of fabricating a self-aligned contact window, wherein a substrate having at least a gate structure or a source/drain region is provided, the method comprising the steps of: forming an undoped dielectric layer over the substrate; implanting dopant into a portion of the undoped dielectric layer, the portion of the dielectric layer being aligned over the gate structure or the source/drain region; and performing an etching process on the portion implanted with dopant with a selectivity that an etchings ratio of the remaining undoped dielectric layer is negligible compared to an etching ratio of the implanted portion until the gate structure or the source/drain region is exposed.

Claim 8

A method of fabricating a self-aligned contact window, wherein a substrate having at least a gate structure or a source/drain region is provided, the method comprising the steps of: forming an undoped dielectric layer over the substrate; implanting dopant into a portion of the undoped dielectric layer, the portion of the dielectric layer being aligned over the gate structure or the source/drain region; and performing an etching process on the portion implanted with dopant with a selectivity that an etchings ratio of the remaining undoped dielectric layer is negligible compared to an etching ratio of the implanted portion until the gate structure or the source/drain region is exposed.

Claim 11

A method of fabricating a self-aligned window to expose a conductive structure on a substrate, the method comprising: forming an undoped dielectric layer on the substrate, the undoped dielectric layer covering the conductive structure; forming a photoresist layer on the undoped dielectric layer, the photoresist layer exposing a portion of the undoped dielectric layer that is to be removed to form the self-aligned contact window subsequently; performing an ion implantation on the undoped dielectric layer with the photoresist layer as a mask, so that the exposed portion of the undoped dielectric layer is transformed into a doped dielectric layer with an etching ratio different from that of the undoped dielectric layer; performing a plasma etching step with a selectivity that an etching ratio of the undoped dielectric layer covered by the photoresist layer is negligible compared to an etching ratio of the doped dielectric layer until the conductive structure is exposed; and removing the photoresist layer.

Claim 12

A method of fabricating a self-aligned window to expose a conductive structure on a substrate, the method comprising: forming an undoped dielectric layer on the substrate, the undoped dielectric layer covering the conductive structure; forming a photoresist layer on the undoped dielectric layer, the photoresist layer exposing a portion of the undoped dielectric layer that is to be removed to form the self-aligned contact window subsequently; performing an ion implantation on the undoped dielectric layer with the photoresist layer as a mask, so that the exposed portion of the undoped dielectric layer is transformed into a doped dielectric layer with an etching ratio different from that of the undoped dielectric layer; performing a plasma etching step with a selectivity that an etching ratio of the undoped dielectric layer covered by the photoresist layer is negligible compared to an etching ratio of the doped dielectric layer until the conductive structure is exposed; and removing the photoresist layer.