Molecular beam epitaxy of semipolar AlN(11(2)over-bar2) and GaN(11(2)over-bar2) on m-sapphire

作者：Lahourcade Lise^*; Bellet Amalric Edith; Monroy Eva; Chauvat Marie Pierre; Ruterana Pierre

来源：Journal of Materials Science: Materials in Electronics , 2008, 19(8-9): 805-809.

DOI：10.1007/s10854-007-9453-8

We report on the plasma-assisted molecular-beam epitaxy of semipolar AlN(11 (2) over bar2) and GaN(11 (2) over bar2) films on (1 (1) over bar 00) m-plane sapphire. AlN deposited on m-sapphire settles into two mAlN crystalline orientation domAlNs, AlN(11 (2) over bar2) and AlN(10 (1) over bar0), whose ratio depends on the III/V ratio. Growth under moderate nitrogen-rich conditions enables to isolate the (11 (2) over bar2) orientation. The in-plane epitaxial relationships of AlN(11 (2) over bar2) on m-plane sapphire are [11 (2) over bar(3) over bar](AlN) parallel to [0001](sapphire) and [1 (1) over bar 00](AlN) parallel to [11 (2) over bar0](sapphire). GaN deposited directly on m-sapphire results in (11 (2) over bar2)-oriented layers with (10 (1) over bar(3) over bar)-oriented inclusions. A similar to 100 nm-thick AlN(11 (2) over bar2) buffer imposes the (11 (2) over bar2)-orientation for the GaN layer grown on top. By studying the Ga-desorption on GaN(11 (2) over bar2), we conclude that these optimal growth conditions corresponds to a Ga excess of one monolayer on the GaN(11 (2) over bar2) surface.

• 出版日期2008-9
• 单位中国地震局