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Browse Prior Art Database

Real Time Etch Plasma Monitor System

IP.com Disclosure Number: IPCOM000045624D
Original Publication Date: 1983-Apr-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 2 page(s) / 72K

Publishing Venue

IBM

Related People

Khoury, HA: AUTHOR

Abstract

This article concerns a monitor for continuously measuring all significant emission species in a plasma used, for example, in a sputterer or reactive ion etch system. By monitoring the species it is possible to determine the etch status and the presence of foreign matter. The monitor features an optical grating for dispersing the plasma radiation into specific wavelengths, a photodiode array for sensing the intensities of the various wavelengths and data processing means for digitizing the diode array signals and analyzing them so as to identify a plasma signature which may be used to analyze the plasma.

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Real Time Etch Plasma Monitor System

This article concerns a monitor for continuously measuring all significant emission species in a plasma used, for example, in a sputterer or reactive ion etch system. By monitoring the species it is possible to determine the etch status and the presence of foreign matter. The monitor features an optical grating for dispersing the plasma radiation into specific wavelengths, a photodiode array for sensing the intensities of the various wavelengths and data processing means for digitizing the diode array signals and analyzing them so as to identify a plasma signature which may be used to analyze the plasma.

A monitor is here described which provides continuous quantitative measurement of all the significant emission species in a plasma. The monitor thus has the ability to perform real-time plasma diagnostics in sputterers or in reactive ion etch systems. The measurement is accomplished by monitoring the emission intensity across the complete spectrum and, thus, the concentration of each species (CO, N, O, C, etc.) in the plasma. These concentrations are a function of the etching process, the elements or compounds being etched, and the presence or absence of foreign matter in the plasma. After proper data acquisition and chemical analysis, the emission data can be utilized to yield process information (go/no-go, normal/abnormal processing, reproducible etching, contaminant type, source of contaminant, tooling problems, etc.).

With reference to Fig. 1, radiation from the plasma 1 passes through a glass window port 2 and enters an optical grating 3 where it is dispersed into specific wavelengths 4. The intensity of each wave wea...