Method and apparatus for anisotropic etching of substrates

• US 6,214,161 B1
• Filed: 08/06/1998
• Issued: 04/10/2001
• Est. Priority Date: 08/07/1997
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Laermer, Franz, Becker, Volker, Schilp, Andrea
• Primary Examiner(s): Utech, Benjamin L.
• Assistant Examiner(s): Tran, Binh X.
• Application Number:
  US09/129,903
• Time in Patent Office: 978 Days
• Field of Search: 156/345, 438/707, 438/729, 438/731, 438/710, 438/711, 216/67, 216/37
• US Class Current: 156/345.48
• CPC Class Codes: H01J 2237/3345 anisotropy
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching

Abstract

Method, apparatus and plasma processing system for anisotropic etching of a substrate using a plasma. A high-frequency alternating electromagnetic field is generated using an inductive coupled plasma source, and a reactive gas or reactive gas mixture is exposed to that high-frequency alternating electromagnetic field in order to generate the plasma. The electrically charged particles of the plasma are accelerated onto the substrate. An aperture having at least one effective surface for electron-ion recombination is inserted between the plasma source and the substrate.

Claims

1. An apparatus for homogenizing a plasma, comprising:

an inductively coupled plasma source generating the plasma; and

an element associated with the inductively coupled plasma source, the element including an orifice plate having an aperture and at least one effective surface for an electron-ion recombination, the at least one effective surface having a dimension extending beyond a plane of the aperture.

2. The apparatus according to claim 1, wherein the element includes an approximately cylindrical attachment.

3. The apparatus according to claim 2, wherein at least one of the orifice plate and the cylindrical attachment is composed of a metal material.

4. The apparatus according to claim 3, wherein the metal material is a fluorine-resistant material.

5. The apparatus according to claim 3, wherein the metal material includes an aluminum material.

6. A plasma processing system for anisotropicly etching a substrate using a plasma, comprising:

a plasma source generating a high-frequency alternating electromagnetic field;

a reactor generating the plasma from reactive particles using the high-frequency alternating electromagnetic field on one of a reactive gas and a reactive gas mixture;

a substrate electrode accelerating an ion current contained in the plasma onto the substrate; and

an element situated between the plasma source and the substrate electrode, the element including an orifice plate having an aperture and at least one effective surface for an electron-ion recombination, the at least one effective surface having a dimension extending beyond a plane of the aperture.

7. The plasma processing system according to claim 6, wherein a diameter of the aperture is greater than a diameter of the substrate.

8. The plasma processing system according to claim 6, further comprising an absorber situated around the substrate for absorbing reactive particles of the plasma.

9. The plasma processing system according to claim 8, wherein the absorber is composed of at least one of a silicon material, a quartz material, a plastic material and a graphite material.

10. A apparatus for anisotropic etching a substrate using a plasma, comprising:

an inductively coupled plasma source generating a high-frequency alternating electromagnetic field, the inductively coupled plasma source generating the plasma by exposing one of a reactive gas and a reactive gas mixture to the high-frequency alternating electromagnetic field, wherein electrically charged particles of the plasma are accelerated onto the substrate; and

an orifice plate having an aperture and arranged between the plasma source and the substrate, the orifice plate having at least one effective surface for an electron-ion recombination which is associated with the aperture, wherein the at least one effective surface is configured as an approximately cylindrical attachment on the orifice plate, and wherein a diameter of the aperture is greater than a diameter of the substrate.

11. An apparatus for anisotropicly etching a substrate, the apparatus comprising:

an arrangement for generating a high-frequency alternating electromagnetic field;

an arrangement for generating a plasma by exposing one of a reactive gas and a reactive gas mixture to the high-frequency alternating electromagnetic field;

an arrangement for accelerating electrically charged particles of the plasma onto the substrate; and

an orifice plate having an aperture being provided between an inductively coupled plasma source and the substrate, the orifice plate being associated with at least one effective surface for an electron-ion recombination, the at least one effective surface having a dimension extending beyond a plane of the aperture.

12. The apparatus according to claim 11, wherein the at least one effective surface includes a cylindrically-shaped surface.

13. The apparatus according to claim 11, herein the at least one effective surface is a cylinder.

14. The apparatus according to claim 11, wherein the at least one effective surface is a cylinder having a vertical dimension of about 25 mm.

15. The apparatus according to claim 11, wherein a diameter of the aperture is no less than a diameter of the substrate.

16. The apparatus according to claim 11, wherein at least one of the orifice plate and the at least one effective surface includes at least one of a metal material, a fluorine-resistant metal and an aluminum material.

17. The apparatus according to claim 11, further comprising an absorber including at least one of a quartz material, a silicon material, a plastic material and a graphite material.