Guided Ultrasonic Waves in Semiconductor Materials

Texas A&M Engineering Experiment Station, College Station TX

Investigators

Abstract

ABSTRACT FOR PUBLIC RELEASE Principal Investigators: Ravinder Chona and Chii-Der S. Suh Department of Mechanical Engineering Texas A&M University College Station, Texas 77843-3123 Proposal Number: 0070846 Proposal Title: Guided Ultrasonic Waves In Semiconductor Materials Project Abstract: The project addresses the need for non-contact temperature monitoring and mapping techniques during Rapid Thermal Processing (RTP) of silicon wafers that have improved accuracy, sensitivity and range as compared to conventional pyrometric methods. The computational and experimental work already in place provides the foundation for development of a physical system which uses Thermal-Acousto-Photonic Non-Destructive Evaluation (TAP-NDE) to generate and detect thermally-dependent, ultrasonic, guided (Lamb) waves. These interrogate the silicon wafer and provide information about the thermal state of the wafer. This study is expected to establish the necessary knowledge base for a better understanding of: surface layer effects; high-temperature dissipative mechanisms; extraction of thermal information in real-time; optimization of thermoelastic generation and optical sensing techniques in severe temperature environments; and adaptation and integration of the method into an algorithm implementable into dedicated Digital Signal Processor (DSP) hardware. Development of the technique has far-reaching impact in other fields as well. For example, high-resolution thermal measurement at high temperatures is needed in manufacturing of high-performance jet engine turbine blades, determination of residual stresses induced by localized high thermal gradient heating, and nano-technology based deposition of thin films/layers in micro-electro-mechanical systems (MEMS).