Method of operating a plasma reactor chamber with respect to two plasma parameters selected from a group comprising ion density, wafer voltage, etch rate and wafer current, by controlling chamber parameters of source power and bias power

• US 20060283835A1
• Filed: 08/23/2006
• Published: 12/21/2006
• Est. Priority Date: 05/16/2003
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Hoffman, Daniel J.
• Granted Patent: US 7,521,370 B2
• Time in Patent Office: Days
• US Class Current: 216/59
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge

Abstract

A workpiece is processed in a plasma reactor chamber in accordance with desired values of two plasma parameters selected from a group comprising ion density, wafer voltage, etch rate and wafer current, by controlling chamber parameters of source power and bias power. First, the chamber is characterized by performing the following steps: (a) for each one of the chamber parameters, ramping the level of the one chamber parameter while sampling RF electrical parameters at an RF bias power input to the wafer support pedestal and computing from each sample of the RF electrical parameters the values of the plasma parameters, and storing the values with the corresponding levels of the one chamber parameter as corresponding chamber parameter data; (b) for each one of the chamber parameters, deducing, from the corresponding chamber parameter data, a single variable function for each of the plasma parameters having the one chamber parameter as an independent variable; (c) constructing combinations of the functions and from the combinations, constructing surfaces defining concurrent values of the chamber parameters, each respective surface corresponding to a respective constant value of one of the plasma parameters, and storing the surfaces.

Claims