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，亚晶格反转外延，用于生长畴反转化合物半导体，并在GaAs/Si/GaAs (100), GaAP/Si/GaP(100), GaAs/Ge/GaAs（100）和GaAs/Ge/GaAs（111）系统中使用MBE进行了演示。通过RHHED观测和优先蚀刻证实了晶格反转（即畴反转）的存在。利用反射SHG技术，我们已经证实，由亚晶格反转外延生长的脱毛层的二次非线性光学系数的符号确实与衬底的符号相反。XTEM观察发现，反相结构域的自灭有助于亚晶格的逆转。XTEM观察还发现，在GaAs/Ge/GaAs（111）体系中，亚晶格反转层的形成主要是异常（111）SIGMA3晶界的形成。周期性畴反转结构的制备我们提出了一种利用GaAs/Ge/GaAs（100）亚晶格反转外延制备AlGaAs周期性畴反转结构的技术。在亚晶格反转外延和蚀刻制备的模板上采用再生工艺，可以生长出不受反相畴影响的周期性畴反转半导体。我们已经成功地制造了高质量的周期性畴反转砷化镓结构。利用这种技术制造波长转换装置的工作正在进行中。

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.