Hot-Wall MOCVD for Highly Efficient and Uniform Growth of AlN

• Published in: Crystal growth & design 2009-02, Vol.9 (2), p.880-884
• Main Authors: Kakanakova-Georgieva, A, Ciechonski, R. R, Forsberg, U, Lundskog, A, Janzén, E
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of crystal growth; physics of crystal growth; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory and models of crystal growth; physics of crystal growth, crystal morphology and orientation; Thin film structure and morphology
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg8005663

We demonstrated successful growth of AlN at a temperature of 1200 °C in a set of hot-wall MOCVD systems with the possibility of straightforward scaling up the process on larger wafer areas to meet the demand of device technologies. We outlined several aspects of the carefully optimized design and process parameters with relevance to achievement of a high overall growth rate (1 and up to 2 μm/h), efficiency, and uniformity, which to a great extent depends on how consumption of growth-limiting species by gas-phase adduct formation can actively be prevented. Mixing of the precursors upstream from the deposition area facilitates uniform epitaxial growth, while the greater uniformity of substrate temperature inherent to the hot-wall reactor and rotation of the wafer are of fundamental importance for layer-growth uniformity. The AlN layer thickness can be controlled with an accuracy of ±1.3% on 2 in. wafers. The low-temperature cathodoluminescence spectrum of the AlN epitaxial material is strongly dominated by the intense near band-gap deep UV emission at about 208 nm.