PLASMA PROCESSING SYSTEM CONTROL BASED ON RF VOLTAGE

• US 20110137446A1
• Filed: 12/07/2010
• Published: 06/09/2011
• Est. Priority Date: 11/19/2009
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Povolny, Henry S., Valcore, John C. JR.
• Granted Patent: US 8,501,631 B2
• Time in Patent Office: Days
• US Class Current: 700/108
• CPC Class Codes: G05B 15/02 electric
• CPC Class Codes: G05B 19/418 Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS] or computer integrated manufacturing [CIM]
• CPC Class Codes: G05B 2219/45031 Manufacturing semiconductor wafers
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32137 controlling of the discharge by modulation of energy
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32183 Matching circuits
• CPC Class Codes: H01J 37/32917 Plasma diagnostics
• CPC Class Codes: H01J 37/32926 Software, data control or modelling
• CPC Class Codes: H01J 37/3299 Feedback systems

Abstract

A method for controlling a plasma processing system using wafer bias information derived from RF voltage information is proposed. The RF voltage is processed via an analog or digital methodology to obtain peak voltage information at least for each of the fundamental frequencies and the broadband frequency. The peak voltage information is then employed to derive the wafer bias information to serve as a feedback or control signal to hardware/software of the plasma processing system.

Claims

1. A method for controlling a plasma processing system, comprising:

receiving an RF signal from at least one component of said chamber;

processing said RF signal in the digital domain to obtain peak voltage information for each fundamental frequency and a broadband frequency of said RF signal; and

deriving wafer bias information from said peak voltage information, wherein said wafer bias information is employed as one of a feed back and a control signal for said controlling said plasma processing system.

2. A method for controlling a plasma processing system, comprising:

receiving an RE signal from at least one component of said chamber;

processing said RF signal to obtain peak voltage information for each fundamental frequency and a broadband frequency of said RF signal; and

deriving wafer bias information from said peak voltage information, wherein said deriving includes using at least one plasma processing chamber parameter in said deriving and wherein said wafer bias information is employed as one of a feed back and a control signal for said controlling said plasma processing system.