Low pressure metalorganic chemical vapor deposition of AIN over sapphire substrates

Abstract

In this letter we report the deposition of high quality single-crystal films of AIN over basal plane sapphire substrates. A conventional low pressure metalorganic chemical vapor deposition (LPMOCVD) system was used for all the growths reported here. We present the results of conventional and switched atomic layer epitaxial (SALE) depositions. Conventional LPMOCVD yielded single-crystal AIN films at temperatures in excess of 750 °C. The ALE process in contrast produced extremely smooth single-crystal AIN layers at temperatures as low as 450 °C. To the best of our knowledge this is the lowest ever reported for chemical vapor deposition of single-crystal AIN. X-ray and optical characterization data are presented to compare the quality of the material resulting from the two deposition techniques.