Methods for selectively removing material
Provided is a conductive structure and a method for forming such a structure. The method includes forming a treatable layer by depositing a layer comprising a metal over a structure; performing a directional treatment process on a targeted portion of the treatable layer to convert the targeted portion to a material different from a non-targeted portion of the treatable layer, wherein the directional treatment process is selected from the group consisting of nitridation, oxidation, chlorination, carbonization; and selectively removing the non-targeted portion from the structure, wherein the targeted portion remains over the structure.
1 . A method, comprising:
forming a treatable layer by depositing a layer comprising a metal over a structure;
performing a directional treatment process on a targeted portion of the treatable layer to convert the targeted portion to a material different from a non-targeted portion of the treatable layer, wherein the directional treatment process is selected from the group consisting of nitridation, oxidation, chlorination, carbonization; and
after performing the directional treatment process on the targeted portion of the treatable layer, selectively removing the non-targeted portion from the structure, wherein the targeted portion remains over the structure.
2 . The method of claim 1 , wherein the layer comprising a metal is a metal layer.
3 . The method of claim 1 , further comprising forming a conductive plug over the targeted portion after performing the directional treatment process on the targeted portion of the treatable layer.
4 . The method of claim 1 , wherein:
the structure includes a cavity sidewall and a cavity bottom;
forming the treatable layer over the structure comprises forming the treatable layer conformally over the cavity sidewall and the cavity bottom;
a bottom portion of the treatable layer lies over the cavity bottom;
a sidewall portion of the treatable layer lies over the cavity sidewall;
the bottom portion is located between the cavity bottom and the sidewall portion of the treatable layer;
the bottom portion of the treatable layer is the targeted portion; and
the sidewall portion of the treatable layer is the non-targeted portion.
5 . The method of claim 4 , further comprising forming a conductive plug over the targeted portion.
6 . The method of claim 1 , wherein the structure comprises:
an epitaxial region;
a silicide layer on the epitaxial region; and
a barrier metal layer on the silicide layer; wherein the treatable layer is formed over the barrier metal layer.
7 . The method of claim 1 , wherein the structure comprises an active region.
8 . The method of claim 1 , wherein the structure comprises a source/drain region.
9 . The method of claim 1 , performing the directional treatment process on the targeted portion of the treatable layer comprises performing a nitridation process.
10 . The method of claim 1 , performing the directional treatment process on the targeted portion of the treatable layer comprises performing an oxidation process.
11 . The method of claim 1 , performing the directional treatment process on the targeted portion of the treatable layer comprises performing a chlorination process.
12 . The method of claim 1 , performing the directional treatment process on the targeted portion of the treatable layer comprises performing a carbonization process.
13 . A method, comprising:
etching a cavity landing on a conductive structure, wherein the cavity is defined by a sidewall, and wherein etching the cavity landing on the conductive structure causes residue from the conductive structure to be located on the sidewall;
forming a first material over the conductive structure and the sidewall, wherein a bottom portion of the first material is located over the conductive structure, and wherein a side portion of the first material is located adjacent the sidewall;
converting the bottom portion to a second material different from the first material; and
selectively removing the side portion and the residue from the sidewall.
14 . The method of claim 13 , further comprising forming a conductive plug in the cavity over the bottom portion located on the conductive structure.
15 . The method of claim 13 , wherein forming the first material over the conductive structure and the sidewall comprises directionally depositing the first material, and wherein a thickness of the bottom portion of the first material is greater than a thickness of the side portion of the first material.
16 . The method of claim 13 , wherein the bottom portion of the first material is located directly on the conductive structure, and wherein a side portion of the first material is located directly on the sidewall.
17 . The method of claim 13 , further comprising forming the conductive structure surrounded by a dielectric material, wherein etching the cavity landing on the conductive structure comprises etching the conductive structure and the dielectric material, wherein the sidewall is formed by the dielectric material, and wherein the cavity is defined by a cavity bottom formed by an upper surface of the conductive structure and an upper surface of the dielectric material.
18 . A method, comprising:
forming a treatable layer by depositing a layer consisting of metal over a structure;
performing a directional treatment process on a targeted portion of the treatable layer to convert the targeted portion to a material different from a non-targeted portion of the treatable layer, wherein the directional treatment process is selected from the group consisting of nitridation, oxidation, chlorination, carbonization; and
selectively removing the non-targeted portion from the structure, wherein the targeted portion remains over the structure.
19 . The method of claim 18 , further comprising forming a conductive plug over the targeted portion after performing the directional treatment process on the targeted portion of the treatable layer.
20 . The method of claim 18 , wherein
the structure includes a cavity sidewall and a cavity bottom;
forming the treatable layer over the structure comprises forming the treatable layer conformally over the cavity sidewall and the cavity bottom;
a bottom portion of the treatable layer lies over the cavity bottom;
a sidewall portion of the treatable layer lies over the cavity sidewall;
the bottom portion is located between the cavity bottom and the sidewall portion of the treatable layer;
the bottom portion of the treatable layer is the targeted portion; and
the sidewall portion of the treatable layer is the non-targeted portion.