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    CVD Deposition of Group-III Nitride Materials

      Asif Khan PhD
     Sep 16, 2014

    LEDs and Transistors: N- and p-doped Layers , Heterojunctions , Quantum Wells and Superlattices. AlN sublimes dissociatively at the hotter source and condenses reversibly at the colder seed. Epitaxial Nitride Films by HVPE: Growth rate is determined by HCl flux , High growth rates are possible due to low probability of gas phase nucleation , Growth rates can exceed 100 mm/min . Various problems associated with mismatches: Growth steps of GaN on sapphire: The lattice mismatch with GaN is 13.9% ! The steps for GaN growth includes: (a) Nitridation and (b) low temperature buffer layer (usually AlN) growth ! Growth on c-plane of sapphire gives c-plane GaN, while growth on r-plane gives a-plane GaN ! Energy gap of sapphire is > 8eV so light extraction possible from substrate side for LEDs . MEMOCVD of III-N Materials: allowing V/III separation hence reducing gas-phase reaction & enhancing surface migration.

    Important Tags: CVD Deposition, Medical Presentation, Free Presentation, Publish Presentation
    Views: 3660
    Domain: Electronics
    Category: Semiconductors

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