STP1340

    Recombination Lifetime Variations and Defect Introduction by Rapid Thermal Processing

    Published: Jan 1998


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    Abstract

    Extended defects generated during RTP processing at the quartz wafer support and contact fingers of the wafer transfer robot have been examined by minority carrier recombination lifetime, τr, and X-Ray Topography. Silicon CZ wafers of 8”dia have been mapped laterally, and the defects imaged as a function of depth. Various RTP chamber cleaning and annealing experiments were carried out to control the reduced lifetime/pin defect formation process. A τr reduction of up to two orders of magnitude can occur at the contact points. The low lifetime has been profiled in-depth by Laser Microwave Photoconductance Decay following sequential sample thinning to yield 3D lifetime maps. HF-passivation was used to lower the impact of surface recombination. A two exponential model was used to separate the surface and bulk components of lifetime, which were resolved by the Nelder-Mead non-linear fitting method. The range of lifetime degradation at the RTP induced defects varies with the level of contamination which occurs during pin/wafer contact. Fortunately, the extended defects, i.e. slip dislocations, are confined to the wafer backside, where they getter the contaminants.

    Keywords:

    laser microwave photoconductance decay, LM-PCD, X-ray topography, XRT, Rapid Thermal Processing, RTP, low lifetime spots, slip dislocations, decontamination monitoring


    Author Information:

    Karoui, A
    Visiting Scientist, North Carolina State University, Raleigh, NC

    Zhang, Q
    Visiting Scientist, North Carolina State University, Raleigh, NC

    Romanowski, A
    Visiting Scientist, North Carolina State University, Raleigh, NC

    Rozgonyi, GA
    Professor, North Carolina State University, Raleigh, NC

    Rushbrook, P
    RTP Project, Mattson Technology Inc., Fremont, CA

    Daviet, JF
    Technology Manager, RTP Project, Mattson Technology Inc., Fremont, CA


    Paper ID: STP15709S

    Committee/Subcommittee: F01.10

    DOI: 10.1520/STP15709S


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