Dry Etching Agent and Dry Etching Method Using the Same

• US 20140242803A1
• Filed: 05/07/2014
• Published: 08/28/2014
• Est. Priority Date: 02/01/2010
• Status: Active Grant

• Current Assignee: Central Glass Company Limited
• Original Assignee: Central Glass Company Limited
• Inventors: HIBINO, Yasuo, UMEZAKI, Tomonori, KIKUCHI, Akiou, MORI, Isamu, OKAMOTO, Satoru
• Granted Patent: US 9,230,821 B2
• Time in Patent Office: Days
• US Class Current: 438/724
• CPC Class Codes: C09K 13/00 Etching, surface-brightening or pickling compositions for glass C03C15/00, C03C25/66; for mortars, concrete, artificial or natural stone or ceramics C04B41/5338 ; for metallic material C23F, C23G1/00, C25F1/00; for semi-conductors H01L
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/31055 the removal being a chemical etching step, e.g. dry etching etching per se H01L21/311
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32136 using plasmas

Abstract

A dry etching agent according to the present invention contains (A) a fluorinated propyne represented by the chemical formula: CF₃C≡CX where X is H, F, Cl, Br, I, CH₃, CFH₂ or CF₂H; and either of: (B) at least one kind of gas selected from the group consisting of O₂, O₃, CO, CO₂, COCl₂ and COF₂; (C) at least one kind of gas selected from the group consisting of F₂, NF₃, Cl₂, Br₂, I₂ and YFn where Y is Cl, Br or I; and n is an integer of 1 to 5; and (D) at least one kind of gas selected from the group consisting of CF₄, CHF₃, C₂F₆, C₂F₅H, C₂F₄H₂, C₃F₈, C₃F₄H₂, C₃ClF₃H and C₄F₈. This dry etching agent has a small environmental load and a wide process window and can be applied for high-aspect-ratio processing without special operations such as substrate excitation.

Claims

1. A dry etching method, comprising:

generating a plasma gas from a dry etching agent; and

selectively etching at least one kind of silicon material selected from the group consisting of silicon dioxide and silicon nitride by the generated plasma gas,

wherein the dry etching agent comprises;

(A) a fluorinated propyne represented by the chemical formula;

CF₃C≡

CX where X is H, F, Cl, Br, I, CH₃, CFH₂ or CF₂H; and

at least one of;

(B) at least one kind of gas selected from the group consisting of O₂, O₃, CO, CO₂, COCl₂ and COF₂;

(C) at least one kind of gas selected from the group consisting of F₂, NF₃, Cl₂, Br₂, I₂ and YFn where Y is Cl, Br or I; and

n is an integer of 1 to 5; and

(D) at least one kind of gas selected from the group consisting of CF₄, CHF₃, C₂F₆, C₂F₅H, C₂F₄H₂, C₃F₈, C₃F₄H₂ and C₄F₈.

2. The dry etching method according to claim 1, wherein the dry etching agent contains (A) CF₃C≡

CH and (E) at least one kind of oxidizing gas selected from the group consisting of O₂, CO and COF₂; and

wherein the ratio of volumetric flow rates of (A) CF₃C≡

CH and (E) oxidizing gas is 5 to 95%;

5 to 95% assuming that the sum of the volumetric flow rates of the respective gas components is 100%.

3. The dry etching method according to claim 1, wherein the dry etching agent contains (A) CF₃C≡

CH, (E) at least one kind of oxidizing gas selected from the group consisting of O₂, CO and COF₂, and Ar; and

wherein the ratio of volumetric flow rates of (A) CF₃C≡

CH, (E) oxidizing gas, and Ar is 5 to 95%;

1 to 50%;

4 to 94% assuming that the sum of the volumetric flow rates of the respective gas components is 100%.

4. The dry etching method according to claim 1, wherein the dry etching agent contains (A) CF₃C≡

CH, (E) at least one kind of oxidizing gas selected from the group consisting of O₂, CO and COF₂, and H₂; and

wherein the ratio of volumetric flow rates of (A) CF₃C≡

CH, (E) oxidizing gas, and H₂ is 5 to 95%;

1 to 50%;

4 to 94% assuming that the sum of the volumetric flow rates of the respective gas components is 100%.

5. The dry etching method according to claim 1, wherein the dry etching agent contains (A) CF₃C≡

CH, (E) at least one kind of oxidizing gas selected from the group consisting of O₂, CO and COF₂, H₂, and Ar; and

wherein the ratio of volumetric flow rates of (A) CF₃C≡

CH, (E) oxidizing gas, H₂, and Ar is 5 to 95%;

1 to 50%;

1 to 50%;

3 to 93% assuming that the sum of the volumetric flow rates of the respective gas components is 100%.

6. The dry etching method according to claim 1, wherein the dry etching agent contains (A) at least one kind of 1-halogeno-3,3,3-trifluoropropyne selected from the group consisting of CF₃C≡

CF, CF₃C≡

CCl and CF₃C≡

CBr and (F) at least one additive gas selected from the group consisting of O₂, CO, H₂ and COF₂; and

wherein the ratio of volumetric flow rates of (A) 1-halogeno-3,3,3-trifluoropropyne and (F) additive gas is 5 to 95%;

5 to 95% assuming that the sum of the volumetric flow rates of the respective gas components is 100%.

7. The dry etching method according to claim 1, wherein the dry etching agent contains:

(A) at least one kind of 1-halogeno-3,3,3-trifluoropropyne selected from the group consisting of CF₃C≡

CF, CF₃C≡

CCl and CF₃C≡

CBr;

(F) at least one additive gas selected from the group consisting of O₂, CO, H₂ and COF₂; and

Ar; and

wherein the ratio of volumetric flow rates of (A) 1-halogeno-3,3,3-trifluoropropyne, (F) additive gas, and Ar is 5 to 95%;

3 to 50%;

2 to 92% assuming that the sum of the volumetric flow rates of the respective gas components is 100%.