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Method for a gas-induced high-yield material for copper etch in an FIB

IP.com Disclosure Number: IPCOM000124058D
Publication Date: 2005-Apr-07
Document File: 3 page(s) / 61K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a gas-induced high-yield material for copper etch in a focus ion beam (FIB). Benefits include improved functionality and improved performance.

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Method for a gas-induced high-yield material for copper etch in an FIB

Disclosed is a method for a gas-induced high-yield material for copper etch in a focus ion beam (FIB). Benefits include improved functionality and improved performance.

Background

      Conventional processes used to cut copper (Cu) in semiconductor devices in the FIB are not selective enough and can etch the surrounding dielectric material while cutting the metal. Etch end pointing is typically based on the FIB image.

      Conventional FIB gas-induced etching is based on a gas-metal interaction induced by the ion beam.

      The inside of a FIB chamber has a vacuum of about 1x 10-7 torr without any gas supply.

General description

      The disclosed method cuts metal (especially Cu) in a semiconductor device inside an FIB.

Advantages

              The disclosed method provides advantages, including:

•             Improved functionality due to creating a salt metal layer that improves the etch process

•             Improved performance due to removing the salt metal layer while removing as little as possible of the dielectric material

Detailed description

      The disclosed method includes a gas induced high yield material (GIHYM). Exposing a device to a flow of halogen gas (such as Cl2) with or without an ion beam process can lead to the formation of a metal salt layer on the metal without affecting the dielectric material. This metal salt has a high sputtering yield to an FIB beam. The salt layer can be removed with the ion beam, resulting in a more selective process that leads to a controllable FIB application, with easier end pointing (etching as little as possible of the dielectric material).

      The disclosed method can be implemented using the following process steps, which are performed inside an FIB chamber (see Figure 1...