High-pressure vessel for growing group III nitride crystals and method of growing group III nitride crystals using high-pressure vessel and group III nitride crystal,申请号US20090455683-传众专利搜索

High-pressure vessel for growing group III nitride crystals and method of growing group III nitride crystals using high-pressure vessel and group III nitride crystal

申请公布号：US8236267(B2)

申请号：US20090455683

申请日期：2009.06.04

申请公布日期：2012.08.07

申请人：

HASHIMOTO TADAO;LETTS EDWARD;IKARI MASANORI;SIXPOINT MATERIALS, INC.

发明人：HASHIMOTO TADAO;LETTS EDWARD;IKARI MASANORI

分类号：C01B21/06;C23C16/00;C30B23/00

主分类号：C01B21/06

摘要：The present invention discloses a high-pressure vessel of large size formed with a limited size of e.g. Ni—Cr based precipitation hardenable superalloy. The vessel may have multiple zones. For instance, the high-pressure vessel may be divided into at least three regions with flow-restricting devices and the crystallization region is set higher temperature than other regions. This structure helps to reliably seal both ends of the high-pressure vessel, and at the same time, may help to greatly reduce unfavorable precipitation of group III nitride at the bottom of the vessel. This invention also discloses novel procedures to grow crystals with improved purity, transparency and structural quality. Alkali metal-containing mineralizers are charged with minimum exposure to oxygen and moisture until the high-pressure vessel is filled with ammonia. Several methods to reduce oxygen contamination during the process steps are presented. Also, back etching of seed crystals and a new temperature ramping scheme to improve structural quality are disclosed.