Final report on LDRD Project: In situ determination of composition and strain during MBE

Technical Report · Sat Feb 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/446385· OSTI ID:446385

Chason, E; Floro, J A; Reno, J; Klem, J

Molecular Beam Epitaxy (MBE) of semiconductor heterostructures for advanced electronic and opto-electronic devices requires precise control of the surface composition and strain. The development of advanced in situ diagnostics for real-time monitoring and process control of strain and composition would enhance the yield, reliability and process flexibility of material grown by MBE and benefit leading-edge programs in microelectronics and photonics. The authors have developed a real-time laser-based technique to measure the evolution of stress in epitaxial films during growth by monitoring the change in the wafer curvature. Research has focused on the evolution of stress during the epitaxial growth of Si{sub x}Ge{sub 1{minus}x} alloys on Si(001) substrates. Initial studies have observed the onset and kinetics of strain relaxation during the growth of heteroepitaxial layers. The technique has also been used to measure the segregation of Ge to the surface during alloy growth with monolayer sensitivity, an order of magnitude better resolution than post-growth characterization. In addition, creation of a 2-dimensional array of parallel beams allows rapid surface profiling of the film stress that can be used to monitor process uniformity.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 446385
• Report Number(s): SAND--97-0295; ON: DE97004355
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
CHEMICAL COMPOSITION
HETEROJUNCTIONS
MOLECULAR BEAM EPITAXY
MONITORING
PROCESS CONTROL
PROGRESS REPORT
REAL TIME SYSTEMS
SEMICONDUCTOR DEVICES
STRESSES