The microstructure, polarity and Si distribution in AlN/GaN layers grown by plasma assisted molecular beam epitaxy on Si(111) was assessed by scanning transmission electron microscopy. Samples grown under both metal-and nitrogen-rich conditions contained defects at the AlN/Si interface which suggest formation of an Al-Si eutectic. Correlated with this, interfacial segregation of Si was found in the samples. It is proposed that Si is dissolved in a eutectic layer floating on the AlN surface under metal-rich conditions. This Si is then incorporated into the film if the growth becomes nitrogen-rich, either intentionally or due to plasma source transients. These Si-rich layers appear to induce inversion of the nitride from nitrogen-to metal-polarity, and uncontrolled variations in the Si concentration cause occasional nonuniformity in the resulting inversion. (C) 2019 The Japan Society of Applied Physics
Related
Batch download
Cited By
noting
Similar Literature
Submit Feedback
Please wait while the file you selected is being converted