Impact of rapid thermal annealing on impurities removal efficiency from silicon carbide for optoelectronic applications

Barbouche M., Zaghouani R. B. , Benammar N. E. , Khirouni K., Turan R., Ezzaouia H.

INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY, vol.106, pp.731-739, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 106
  • Publication Date: 2020
  • Doi Number: 10.1007/s00170-019-04556-7
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, IBZ Online, Compendex, INSPEC, DIALNET
  • Page Numbers: pp.731-739
  • Keywords: Silicon carbide, Gettering, Impurities, Passivation, Minority carrier lifetime, Electrical parameters, ELECTRICAL-PROPERTIES, OPTICAL-PROPERTIES, THIN-FILMS, SCHOTTKY DIODES, PURIFICATION, TEMPERATURE, CARBON, PECVD, RICH, DEPOSITION
  • Middle East Technical University Affiliated: Yes


Impurities are of crucial interest in optoelectronic devices as they affect carrier lifetimes and electrical properties. In view of that, it is important to incorporate certain processing steps to reduce impurities effect on final devices. The aim of this work is to enhance silicon carbide SiC purity for silicon passivation. Low cost method of SiC purification is presented. This method combines three main steps consisting of formation of porous silicon carbide layers by acid vapor etching followed by a photo-thermal annealing at different temperatures. Finally, obtained SiC powder was subject to a chemical treatment to remove porous SiC layer. Effect of gettering temperature on purification efficiency was evaluated by inductively coupled plasma atomic emission spectrometry (ICP-AES). The gettering experiment was performed at 800-950 degrees C, and optimum results were obtained at 950 degrees C. SiC purity is improved from 3 N (99.977%) to 5 N (99.999%) with an impurity removal efficiency of 96.56%. Purified SiC was used as a target to synthesize SiC layers using pulsed laser deposition technique (PLD) for optoelectronic devices. The use of intrinsic amorphous silicon carbide (a-SiC) passivating layers was investigated especially by photoconductivity decay technique. Improved SiC target purity leads to a significant enhancement of a-SiC passivating properties attributed to the surface recombination velocity decrease. Electrical properties of a-SiC/c-Si(p) were also studied using I-V and C-V techniques.