Dielectric densification
A low thermal budget dielectric material treatment is provided. An example method of the present disclosure includes providing a semiconductor structure, depositing a dielectric material over the semiconductor structure, treating the dielectric material with a gaseous species carried in a supercritical fluid, and after the treating, reducing a thickness of the dielectric material.
1 . A method, comprising:
providing a semiconductor structure, the semiconductor structure comprising a dielectric layer, at least one hard mask layer over the dielectric layer, and an opening extending through the at least one hard mask layer and the dielectric layer;
depositing a dielectric material over the opening;
after the depositing, treating the dielectric material with a gaseous species carried in a supercritical fluid; and
after the treating, reducing a thickness of the dielectric material,
wherein the reducing of the thickness of the dielectric material comprises removing the at least one hard mask layer and a portion of the dielectric layer.
2 . The method of claim 1 ,
wherein the dielectric material comprises silicon and oxygen.
3 . The method of claim 1 , wherein the gaseous species comprises hydrogen gas (H 2 ) or oxygen gas (O 2 ).
4 . The method of claim 1 , wherein the supercritical fluid comprises supercritical carbon dioxide.
5 . The method of claim 4 , wherein the supercritical fluid comprises a temperature between than 100° C. and about 200° C.
6 . The method of claim 4 , wherein the supercritical fluid comprises a pressure between about 100 atmosphere (atm) and about 200 atm.
7 . The method of claim 1 , wherein the reducing of the thickness of the dielectric material comprises etching or planarization.
8 . The method of claim 7 , wherein the planarization comprises chemical mechanical polishing (CMP).
9 . A method, comprising:
receiving a workpiece that comprises:
at least one channel structure in a gate trench, and
a work function layer wrapping around the at least one channel structure;
depositing a dielectric material over the gate trench, the at least one channel structure and the work function layer;
treating the dielectric material with a gaseous species carried in a supercritical fluid; and
after the treating, reducing a thickness of the dielectric material such that a top surface of the dielectric material is lower than a topmost surface of the at least one channel structure.
10 . The method of claim 9 , wherein the dielectric material comprises silicon, carbon, hydrogen, and oxygen.
11 . The method of claim 9 ,
wherein the gaseous species comprises hydrogen gas (H 2 ) or oxygen gas (O 2 ),
wherein the supercritical fluid comprises supercritical carbon dioxide.
12 . The method of claim 9 ,
wherein the supercritical fluid comprises a temperature greater than 31° C.,
wherein the supercritical fluid comprises a pressure greater than 72.8 atmosphere (atm).
13 . A method, comprising:
providing a semiconductor structure comprising:
first bottom channel members,
first top channel members over the first bottom channel members,
second bottom channel members,
second top channel members over the second bottom channel members,
a first bottom gate structure wrapping around the first bottom channel members,
a first top gate structure wrapping around the first top channel members,
a second bottom gate structure wrapping around the second bottom channel members,
a second top gate structure wrapping around the second top channel members, and
an opening extending from between the first bottom gate structure and the second bottom gate structure to between the first top gate structure and the second top gate structure;
depositing a dielectric material over the first top gate structure, the second top gate structure, and the opening;
performing a low-thermal-budget dielectric densification treatment to the dielectric material; and
after the performing, reducing a thickness of the dielectric material,
wherein an aspect ratio of the opening is between about 4 and about 12,
wherein the low-thermal-budget dielectric densification treatment comprises use of a supercritical fluid.
14 . The method of claim 13 , wherein the low-thermal-budget dielectric densification treatment further comprises use of hydrogen gas (H 2 ) and oxygen gas (O 2 ).
15 . The method of claim 13 , wherein the dielectric material comprises silicon, carbon, hydrogen, and oxygen.
16 . The method of claim 13 , wherein the supercritical fluid comprises supercritical carbon dioxide.
17 . The method of claim 13 , wherein the supercritical fluid comprises a temperature between than 100° C. and about 200° C.
18 . The method of claim 13 , wherein the supercritical fluid comprises a pressure between about 100 atmosphere (atm) and about 200 atm.
19 . The method of claim 13 , wherein the reducing of the thickness of the dielectric material comprises etching or planarization.
20 . The method of claim 13 ,
wherein the first bottom gate structure is a p-type gate structure,
wherein the first top gate structure is an n-type gate structure.