Influence of sputter power and N 2 gas flow ratio on crystalline quality of AlN layers deposited at 823 K by RF reactive sputtering

Tomoyuki Kumada, Makoto Ohtsuka, Kazuya Takada, Hiroyuki Fukuyama

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

Aluminum nitride (AlN) is increasingly demanded for use as a substrate for ultraviolet light emitting diodes (UV-LEDs). A previous study investigated the influence of sputter conditions on the crystalline quality of AlN layers sputtered on nitrided sapphire substrate at 573 and 773 K using radio-frequency (RF) reactive sputtering. AlN layers were deposited at a higher substrate temperature of 823 K to investigate the influence of sputter power and N 2 gas flow ratio on their crystalline quality in this study. The AlN layers were deposited in various conditions (sputter power, 200-900 W; N 2 gas flow ratio, 30-70 vol%N 2). The growth rate increased concomitantly with increasing sputter power and decreasing N 2 gas flow ratio. The crystalline orientation improved with increasing sputter power, except for 900 W at 50 vol%N 2. High-quality c-axis oriented AlN layers were sputtered with 700 W at 50 vol%N 2, and with 800 W at 40 and 50 vol%N 2. Results showed that edge dislocation was dominant in AlN layers sputtered with 800 W at 50 vol%N 2 from cross-sectional images observed using transmission electron microscopy (TEM).

Original languageEnglish
Pages (from-to)515-518
Number of pages4
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Volume9
Issue number3-4
DOIs
Publication statusPublished - 2012 Mar 1

Keywords

  • Aluminum nitride
  • Crystalline quality
  • Reactive sputtering
  • Sapphire nitridation
  • Thin film
  • X-ray diffraction

ASJC Scopus subject areas

  • Condensed Matter Physics

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