Accession Number : ADA329734

Title :   Sensors for In-Situ Process Monitoring and Process Control

Descriptive Note : Final rept. 15 Sep 93-14 Sep 96

Corporate Author : STANFORD UNIV CA EDWARD L GINZTON LAB OF PHYSICS

Personal Author(s) : Khuri-Yakub, B. T. ; Saraswat, Krishna C.

PDF Url : ADA329734

Report Date : SEP 1996

Pagination or Media Count : 31

Abstract : This report presents the results of the development of an ultrasonic sensor for in-situ monitoring of silicon wafer temperature. The sensor is based on the measurement of the velocity of ultrasonic Lamb waves in the wafer, and relating this velocity to temperature. We present a method for efficient excitation and detection of Lamb waves in the wafer, a theoretical model for relating the variation of velocity as a function of temperature, and an electronic implementation for the sensor. Our results indicate the ability to measure the temperature with an accuracy of 10C in most integrated circuit processing environments. The sensor has also been used in a tomographic configuration to allow the measurement of spatial distribution of temperature. Finally, we highlight the potential for simultaneous measurement of temperature and film thickness in-situ.

Descriptors :   *ULTRASONICS, *ACOUSTIC DETECTORS, SPATIAL DISTRIBUTION, ACOUSTIC WAVES, THIN FILMS, INTEGRATED CIRCUITS, SEMICONDUCTORS, TEMPERATURE CONTROL, WAFERS.

Subject Categories : Acoustic Detection and Detectors
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE