Plasma etch processes

A method for plasma processing a workpiece using a fluorine-containing plasma which comprises:

• a) coupling RF energy into the plasma region of a vacuum chamber;
• b) feeding a fluorine-containing processing gas into said plasma region, thereby creating a plasma from said processing gas;
• and
• c) independently heating a wall of said chamber, wherein said wall is lined with silicon.

A method for plasma processing a workpiece using a fluorine-containing plasma which comprises

• a) coupling RF energy from an external RF power supply into the plasma region of a vacuum chamber;
• b) feeding a fluorine-containing processing gas into said plasma region, thereby creating a plasma from said processing gas;
• c) placing a solid scavenger for fluorine comprising silicon in contact with the plasma in an area above the workpiece;
• and
• d) independently heating said solid scavenger.

A plasma etch process comprising

• a) providing a vacuum chamber for generating a plasma,
• b) supporting an article to be processed on a support electrode in the chamber;
• c) supplying a fluorine-containing etch gas to the chamber;
• d) coupling RF power via the support electrode for generating a plasma for processing said article;
• and
• e) providing a solid source of silicon that is independently heated to the plasma.

A method of plasma processing a workpiece within a vacuum chamber comprising:

• a) coupling RF energy through a wall of the chamber into a plasma region in the chamber, which region overlies the workpiece,
• b) feeding a fluorine-containing processing gas into said plasma region to create a plasma from said processing gas;
• and
• c) controlling a temperature of said wall by independently heating the wall surrounding the plasma region.

A method for plasma processing a workpiece using a fluorine-containing plasma which comprises:

• a) coupling RF energy into a plasma region of a vacuum chamber;
• b) supplying a fluorine-containing processing gas into said plasma region, to create a plasma from said processing gas;
• c) mounting a solid scavenger for fluorine comprising silicon in contact with the plasma;
• and
• d) independently heating said silicon.

A plasma etch process comprising

• a) providing a vacuum chamber for generating a plasma;
• b) supporting an article to be processed on a support electrode in the chamber;
• c) supplying a fluorine-containing etch gas to the chamber;
• d) coupling RF energy from an external RF power supply through a wall of said chamber to generate a plasma from said etch gas in the chamber;
• and
• e) exposing an active solid source of silicon to the plasma for scavenging fluorine.