Etching apparatus

• US 8,986,493 B2
• Filed: 12/18/2012
• Issued: 03/24/2015
• Est. Priority Date: 03/25/2005
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Tahara, Shigeru, Nishino, Masaru
• Primary Examiner(s): Lund, Jeffrie R
• Assistant Examiner(s): Chandra, Satish
• Application Number:
  US13/717,812
• Publication Number:
  US 20130118688A1
• Time in Patent Office: 826 Days
• Field of Search: 156/345.33, 156/345.34, 156/345.26, 118/715, 216/37, 216/72, 216/74, 216/79
• US Class Current: 156/345.26
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 21/30604 Chemical etching
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31138 by dry-etching

Abstract

When a substrate is etched by using a processing gas including a first gas containing halogen and carbon and having a carbon number of two or less per molecule, while supplying the processing gas toward the substrate independently from a central and a peripheral portion of a gas supply unit, which face the central and the periphery part of the substrate respectively, the processing gas is supplied such that a gas flow rate is greater in the central portion than in the peripheral portion. When the substrate is etched by using a processing gas including a second gas containing halogen and carbon and having a carbon number of three or more per molecule, the processing gas is supplied such that a gas flow rate is greater in the peripheral portion than in the central portion.

Claims

1. An etching apparatus for performing etching of an etching target film of a substrate by using processing gases that include a first processing gas and a second processing gas, the etching apparatus comprising:

a processing chamber in which a susceptor for mounting the substrate thereon is disposed;

at least one first gas supply source containing a first gas that includes at least one of a CH₂F₂ gas, a CHF₃ gas, CF₄ gas or a C₂F₆ gas;

at least one second gas supply source containing a second gas that includes at least one of a C₃F₈ gas, a C₄F₈ gas, a C₄F₆ gas, or a C₅F₈ gas;

at least one mixing arrangement which mixes the gas and the second gas to form the first processing gas and the second processing gas, wherein each of the first processing gas and the second processing gas is a gaseous mixture of the first gas and the second gas;

a gas supply unit, disposed in the processing chamber to face the susceptor, for simultaneously supplying the first processing gas and the second processing gas, the gas supply unit having a gas supply surface facing the susceptor;

a first gas introduction line connected to a central portion of the gas supply unit for supplying the first processing gas to the central portion of the gas supply unit;

a second gas introduction line connected to a peripheral portion of the gas supply unit for supplying the second processing gas to the peripheral portion of the gas supply unit;

a first flow rate control unit disposed at the first gas introduction line;

a second flow rate control unit disposed at the second gas introduction line; and

a controller for controlling the supply of the first processing gas and the second processing gas,

wherein the gas supply unit comprises a first gas introduction chamber for supplying the first processing gas to a central part of the substrate and a second gas introduction chamber for supplying the second processing gas to a peripheral part of the substrate,

wherein the controller is programmed to control the supplying of the first processing gas and the second processing gas such that a flow rate of the first gas from the gas supply unit per unit area of the gas supply surface of the gas supply unit is greater in the central portion than in the peripheral portion and, simultaneously, a flow rate of the second gas from the gas supply unit per unit area of the gas supply surface of the gas supply unit is greater in the peripheral portion than in the central portion.

2. The etching apparatus of claim 1, wherein the first processing gas and the second processing gas comprise a dilution gas and wherein at least one of a dilution rate of the first gas and a dilution rate of the second gas is controlled by the dilution gas.

3. The etching apparatus of claim 1, wherein the at least one gas mixing arrangement comprises:

a first gas mixing arrangement that is configured to control a mixing ratio of the first gas to the second gas to form the first processing gas; and

a second gas mixing arrangement that is configured to control a mixing ratio of the first gas to the second gas to form the second processing gas,

wherein the controller controls the first gas mixing arrangement and the second gas mixing arrangement such that the mixing ratio of the first gas to the second gas in the first processing gas is different than the mixing ratio of the first gas to the second gas in the second processing gas; and

wherein the first gas introduction line connects an outlet of the first gas mixing arrangement to an inlet of the central portion of the gas supply unit, and wherein the second gas introduction line connects an outlet of the second gas mixing arrangement to an inlet of the peripheral portion gas supply unit,

wherein the first flow rate control unit controls a flow rate of the first processing gas downstream of the first gas mixing arrangement,

wherein the second flow rate control unit controls a flow rate of the second processing gas downstream of the second gas mixing arrangement.

4. The etching apparatus of claim 3,

wherein the first gas mixing arrangement comprises a third flow rate control unit and a fourth flow rate control unit, wherein the third flow rate control unit is connected to the at least one first gas supply source, and

wherein the fourth flow rate control unit is connected to the at least one second gas supply source.

5. The etching apparatus of claim 3,

wherein the at least one first gas supply source includes one first gas supply source and another first gas supply source;

wherein the at least one second gas supply source includes one second gas supply source and another second gas supply source;

wherein the first gas mixing arrangement is configured to mix gas from said one first gas supply source and said one second gas supply source and includes a third flow rate control unit connected to said one first gas supply source and a fourth flow rate control unit connected to said one second gas supply source; and

wherein the second gas mixing arrangement is configured to mix gas from said another first gas supply source and said another second gas supply source and includes a fifth flow rate control unit connected to said another first gas supply source and a sixth flow rate control unit connected to said another second gas supply source.

6. An etching apparatus for performing etching of an etching target film of a substrate by using processing gases that include a first processing gas and a second processing gas, the etching apparatus comprising:

a processing chamber in which a susceptor for mounting the substrate thereon is disposed;

at least one first gas supply source containing a first gas that includes a halogen and carbon having a carbon number of two or less per molecule;

at least one second gas supply source containing a second gas that includes a halogen and carbon having a carbon number of three or more per molecule;

a gas supply unit, disposed in the processing chamber to face the susceptor, for simultaneously supplying the first processing gas and the second processing gas, the gas supply unit haying a gas supply surface facing the susceptor;

a controller;

a first gas mixing arrangement that mixes the first gas and the second gas to form the first processing gas, wherein the controller controls the first gas mixing arrangement to control a mixing ratio of the first gas to the second gas in the first processing gas;

a second gas mixing arrangement that mixes the first gas and the second gas to form the second processing gas, wherein the controller controls the second gas mixing arrangement to control a mixing ratio of the first gas to the second gas in the second processing gas, and wherein the mixing ratio of the first gas to the second gas in the first processing gas is different than the mixing ratio of the first gas to the second gas in the second processing gas;

a first gas introduction line connecting an outlet of the first gas mixing arrangement to an inlet of a central portion of the gas supply unit for supplying the first processing gas to the central portion of the gas supply unit;

a second gas introduction line connecting an outlet of the second gas mixing arrangement to an inlet of a peripheral portion of the gas supply unit for supplying the second processing gas to the peripheral portion of the gas supply unit;

a first downstream flow rate control unit disposed at the first gas introduction line and configured to control a flow rate of the first processing gas downstream of the first gas mixing arrangement;

a second downstream flow rate control unit disposed at the second gas introduction line and configured to control a flow rate of the second processing gas downstream of the second gas mixing arrangement,

wherein the gas supply unit comprises a first gas introduction chamber for supplying the first processing gas to a central part of the substrate and a second gas introduction chamber for supplying the second processing gas to a peripheral part of the substrate,

wherein the controller is programmed to control the first gas mixing arrangement, the second gas mixing arrangement, the first downstream flow rate control unit, and the second downstream flow rate control unit such that a flow rate of the first gas per unit area of the gas supply surface of the gas supply unit is greater in the central portion than in the peripheral portion and, simultaneously, a flow rate of the second gas per unit area of the gas supply surface of the gas supply unit is greater in the peripheral portion than in the central portion.

7. The etching apparatus of claim 6, wherein the first set of one or more gas supply sources contain at least one of a CH₂F₂ gas, a CHF₃ gas, a CF₄ gas or a C₂F₆ gas.

8. The etching apparatus of claim 7, wherein the second set of one or more gas supply sources contain at least one of a C₃F₈ gas, a C₄F₈ gas, a C₄F₆ gas, or a C₅F₈ gas.

9. The etching apparatus of claim 8,

wherein the at least one first gas supply source includes one first gas supply source and another first gas supply source;

wherein the at least one second gas supply source includes one second gas supply source and another second gas supply source;

wherein the first mixing arrangement is configured to mix gas from said one first gas supply source and said one second gas supply source and includes a third flow rate control unit connected to said one first gas supply source and a fourth flow rate control unit connected to said one second gas supply source; and

wherein the second gas mixing arrangement is configured to mix gas from said another first gas supply source and said another second gas supply source and includes a fifth flow rate control unit connected to said another first gas supply source and a sixth flow rate control unit connected to said another second gas supply source.

10. The etching apparatus of claim 6,

wherein the at least one first gas supply source includes one first gas supply source and another first gas supply source;

wherein the at least one second gas supply source includes one second gas supply source and another second gas supply source;

wherein the first mixing arrangement is configured to mix gas from said one first gas supply source and said one second gas supply source and includes a third flow rate control unit connected to said one first gas supply source and a fourth flow rate control unit connected to said one second gas supply source; and

wherein the second gas mixing arrangement is configured to mix gas from said another first gas supply source and said another second gas supply source and includes a fifth flow rate control unit connected to said another first gas supply source and a sixth flow rate control unit connected to said another second gas supply source.