*** ABSTRACT 9661283 Kessler This Small Business Innovation Research Phase I project will combine ultra-sensitive optical absorption spectroscopy and frequency-quadrupled diode laser light sources for the development of an atomic mass flux sensor for semiconductor fabrication. Increasingly complex nanoscale electronic devices require that production facilities maintain fine control of the atomic and molecular fluxes during the fabrication process (e.g., MBE, CVD). This requires the development of a new class of flux monitors which are species specific and capable of the precision and accuracy needed for depositing single atomic layers. Physical Sciences Inc. (PSI) has recently demonstrated sensitive mass flux measurements by recording velocity and number density measurements of molecular oxygen molecules in an aeropropulsion field demonstration. PSI proposes to apply the same technique to atomic species by developing and demonstrating a frequency-quadrupled diode laser source in a compact and tunable configuration suitable for various atomic flux measurements. During the Phase I program, ultra-sensitive dopant atomic concentration measurements will be demonstrated using a heat pipe atom source. Mass flux measurements and control will be demonstrated in Phase II in atomic flows produced by an MBE oven source. The flux sensor/controller prototype demonstration will be applicable to a wide variety of both atomic and molecular species flux measurements. The proposed sensor will advance the state-of-the-art for the control of atomic mass flux during fabrication of electronic devices. The sensor will also be applicable to molecular species by changing the laser source wavelength and thus will be applicable to MBE variants and manufacturing via MOCVD. Additional markets may be found in industrial process controls, aeropropulsion applications, and environmental monitoring. ***
