Hopping conduction range of heavily Al-doped 4H-SiC thick epilayers grown by CVD. (19th November 2015)

• Record Type: Journal Article
• Authors: Ji, Shiyang; Eto, Kazuma; Yoshida, Sadafumi; Kojima, Kazutoshi; Ishida, Yuuki; Saito, Shingo; Tsuchida, Hidekazu; Okumura, Hajime
• Is Part Of: Applied physics express. Volume 8:Number 12(2015:Dec.)
• Publication Date: 2015-11-19
• Subjects: Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.7567/APEX.8.121302
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: To outline the hopping conduction range, the electrical characteristics of CVD-grown heavily Al-doped 4H-SiC thick epilayers (2.0 × 10 19 –4.0 × 10 20 cm −3 ) were investigated in a wide temperature regime (20–900 K). It is found that, below 100 K, hopping conduction dominates the carrier transport for all epilayers, and the corresponding hopping conduction activation energy shows a maximum of ∼30 meV at around 1.1 × 10 20 cm −3 . With increasing doping level, the temperature dependence of resistivity evolves and finally obeys the ∼1/ T 1/4 law in the entire temperature regime, which gives direct evidence of variable-range hopping conduction.