JP2022032965A5 - - Google Patents

Claims (12)

(a) providing a silicon-containing substrate on a support;
(b) etching the substrate with a plasma generated from a first gas comprising a fluorine-containing gas to form an etched feature having a bottom;
(c) generating a plasma from a second gas containing hydrogen fluoride (HF) gas to selectively form a condensed or solidified layer of HF on the bottom of the etched features;
(d) applying bias power to the support and etching the bottom with the plasma generated from the second gas ;
The etching method, wherein the temperature of the substrate is maintained at 0° C. or lower in the steps (c) to (d). The step (c) and the step (d) are performed simultaneously,
The etching method according to claim 1. The step (c) and the step (d) are performed with the etching shape having an opening diameter of 200 nm or less and an aspect ratio of 20 or more.
The etching method according to claim 1 or 2. After the step (a), setting the temperature of the substrate to −40° C. or lower;
The etching method according to any one of claims 1 to 3. The step (d) etches the bottom portion with a plasma generated from the second gas or a plasma generated from a rare gas.
The etching method according to any one of claims 1 to 4. The ions in the plasma generated from the second gas are attracted to the bottom, and the condensed layer or solidified layer formed on the bottom and the bottom are reacted to progress the etching.
The etching method according to any one of claims 1 to 5. providing a silicon-containing substrate on a support within the chamber;
setting the temperature of the substrate to 0° C. or lower ;
a step of supplying hydrogen fluoride (HF) gas containing 30% or more by volume flow rate to the total flow rate of the processing gas into the chamber;
supplying high-frequency power and etching the substrate with plasma generated from the processing gas;
The etching method, wherein the temperature of the substrate is maintained at 0° C. or less during the supplying step and the etching step. The setting step includes setting the temperature of the substrate to −40° C. or lower,
The temperature of the substrate is kept below 0° C. during the providing step and the etching step.
The etching method according to claim 7. The substrate containing silicon includes a silicon oxide film or a silicon nitride film,
The etching method according to any one of claims 1 to 8. The substrate containing silicon includes a laminated film of a silicon oxide film and a silicon nitride film,
The etching method according to any one of claims 1 to 8. The substrate containing silicon includes a laminated film of a silicon oxide film and polysilicon,
The etching method according to any one of claims 1 to 8. A plasma etching apparatus,
a chamber;
a support table provided in the chamber for supporting the substrate;
a plasma generator that generates plasma in the chamber;
a control unit;
The control unit
(a) receiving and supporting a silicon-containing substrate on said support;
(b) etching the substrate with a plasma generated from a first gas comprising a fluorine-containing gas to form an etched feature having a bottom;
(c) generating a plasma from a second gas containing hydrogen fluoride (HF) gas to selectively form a condensed or solidified layer of HF on the bottom of the etched features;
(d) applying bias power to the support and etching the bottom with the plasma generated from the second gas ;
A plasma etching apparatus, wherein the temperature of the substrate is maintained at 0° C. or lower in the steps (c) to (d).