Bulk ZnO: Current Status, Challenges, and Prospects

• Published in: Proceedings of the IEEE Vol. 98; no. 7; pp. 1339 - 1350
• Main Authors: Avrutin, Vitaliy, Cantwell, Gene, Zhang, Jizhi, Song, J. J., Silversmith, Donald J., Morkoc, Hadis
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2010; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bridgman method; Chemical industry; Crystal growth; Crystals; Gallium nitride; hydrothermal method; Mass production; Melts; Microelectronics; Mineralization; Optoelectronic devices; Optoelectronics; Senior members; single crystals; Substrates; Transport; vapor transport; Wafers; Zinc oxide
• ISSN: 0018-9219; 1558-2256
• DOI: 10.1109/JPROC.2010.2040363

Rediscovered in the last decade, zinc oxide (ZnO) shows a great potential for many optoelectronics and to some extent microelectronics applications. However, a clear majority of effort expended in this fast developing field has been limited to heteroepitaxial structures grown on foreign substrates with lattice-parameter and thermal-expansion mismatch with ZnO which is detrimental. Recognizing the importance, the effort has shifted to include developing technologies capable of producing freestanding ZnO wafers in large-scale for ZnO based device applications, which is the subject matter of this manuscript. Three competing approaches - hydrothermal method, melt growth (modifications of the well known Bridgman technique), and seeded vapor transport growth - have now reached or are approaching commercial viability. In this article, we discuss the progress, outstanding problems, and prospects of these growth methods employed for commercial manufacturing of ZnO wafers.