Domain-Inversion Epitaxy and Its Application to Wavelength Conversion Devices

我们提出了一种新的外延生长技术，即亚晶格反转外延技术，用于生长磁畴反转化合物半导体，并用分子束外延技术在GaAs/Si/GaP(100)、GAAP/Si/GaP(100)、GaAs/Ge/GaP(100)和GaAs/Ge/GaAs(111)系统中进行了实验研究，通过RHED观察和择优刻蚀证实了这种外延技术的有效性。亚晶格反转外延层的表征我们用反射倍频技术证实了亚晶格反转外延生长的外延层的二次非线性光学系数的符号确实相对于衬底的符号是反转的。对生长的外延层的XTEM观察表明，反相区的自零化有助于亚晶格的反转。X射线电子显微镜观察还发现，在GaAs/Ge/GaAs(111)系统中，亚晶格反转外延层主要由异常的(111)SIGMA3晶界的形成所主导。周期磁畴反转结构的制备我们提出了一种利用GaAs/Ge/GaAs(100)亚晶格反转外延技术制备AlGaAs周期磁畴反转结构的技术。在亚晶格反向外延和刻蚀制备的模板上采用再生长工艺，可以生长出无反相畴的周期性磁畴反转半导体。我们已经成功地制备出了高质量的周期磁畴反转结构。使用这种技术的波长转换器件的制造现在正在进行中。

We have proposed a novel epitaxial growth technique, sublattice reversal epitaxy, for growing domain inverted compound semiconductors, and demonstrated in GaAs/Si/GaAs (100), GaAP/Si/GaP(100), GaAs/Ge/GaAs (100), and GaAs/Ge/GaAs(111) systems using MBE.Stiblattice reversal (i.e. domain inversion) has been confirmed by RHHED observation and preferential etching.2. Characterization of Sublattice Reversed EpilayersWe have confirmed that the sign of the quadratic nonlinear optical coefficient of the epilayer grown by the sublattice-reversal epitaxy is indeed reversed with respect to that of the substrate using the reflection SHG technique. XTEM observation of the grown epilayers revealed that sublattice reversal was assisted by the selfanihilation of antiphase domains. XTEM observation revealed, also, that sublattice reversed epilayer in the GaAs/Ge/GaAs(111) system was dominated by the formation of unusual (111) SIGMA3 grain boundaries.3. Fabrication of Periodically Domain Inverted StructuresWe have proposed a technique for fabricating periodically domain inverted structures of AlGaAs using GaAs/Ge/GaAs(100) sublattice reversal epitaxy. Using regrowth procedure on template fabricated by sublattice reversal epitaxy and etching, periodically domain inverted semiconductors free from antiphase domain can be grown. We have succeeded in fabricating periodically domain inverted GaAs structures of very high quality. Fabrication of wavelength conversion devices using this technique is now in progress.