In situ, non-destructive CVD surface monitor

US5386121A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Steven G. Barbee · Beekman, US
• Tony F. Heinz · Chappaqua, US
• Leping Li · Poughkeepsie, US
• Victor J. Silvestri · Hopewell Junction, US

Key dates

• Filing date: Dec 23, 1993
• Grant date: Jan 31, 1995
• Expiry date: Dec 23, 2013

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N21/94
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A non-intrusive, in-situ monitoring technique and apparatus is used for evaluating the presence and extent of a critical contaminating or passivating layer on a transparent sample, prior to a subsequent process step. A multiple internal reflection apparatus and method without the need for aligning mirrors reduces the time to maximize the light intensity through the sample and to the detector and eliminates the intensity loss due to reflection from each mirror. The technique and apparatus can be used to monitor for a critical hydrogen passivation layer so that it is maintained on the silicon surface right up to the point at which the reactants are introduced for the deposition. The in-situ monitoring and process control technique uses Fourier Transform Infrared Spectroscopy with Multiple Internal Reflections (FTIRS-MIR) which looks at the Si--H bond vibration. Apparatus implementing the technique provides a means of insuring reproducibility in films through direct monitoring of the passivating layer. The technique can be utilized in UHV Chemical Vapor Deposition (CVD) Low Pressure CVD (LPCVD), mid-pressure and atmospheric Chemical Vapor Deposition (CVD) systems. The technique provid…