MOVPE growth and characterization of a-plane AlGaN over the entire composition range

作者：Laskar Masihhur R^*; Ganguli Tapas; Rahman A A; Shah A P; Gokhale M R; Bhattacharya Arnab

来源：Physica Status Solidi-Rapid Research Letters, 2010, 4(7): 163-165.

DOI：10.1002/pssr.201004091

• III-V semiconductors
• AlGaN
• MOCVD
• X-ray diffraction

We report the metal organic vapor phase epitaxy (MOVPE) growth and characterization of non polar (1120) a-plane A1(x)Ga(1-x)N on (1 (1) over bar 02) r-plane sapphire substrates over the entire composition range. A1(x)Ga(1-x)N samples with similar to 0.8 mu m thick layers and with x = 0, 0.18, 0.38, 0.46, 0.66, and 1.0 have been grown on r-plane sapphire substrates. The layer quality can be improved by using a 3-stage AIN nucleation layer and appropriate V/III ratio switching following nucleation. All a-plane AlGaN cpilayers show an anisotropic in-plane mosaicity; strongly influenced by Al incorporation and growth conditions. Careful lattice parameter measurements show anisotropic in-plane strain that results in an orthorhombic distortion of the hexagonal unit cell, making Al composition determination from X-ray diffraction difficult. In general lower Al incorporation is seen in a-plane epilayers compared to c-plane samples grown under the same conditions.

• 出版日期2010-7