Fabrication of Long-Life Laser Diodes in GaAs films on Si formed by annealing under ultrahigh pressure

在超高压退火形成的 Si 上的 GaAs 薄膜中制造长寿命激光二极管

基本信息

批准号：
07555003
负责人：
ISHIWARA Hiroshi
金额：
$ 5.76万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555003/
关键词：
ultrahigh pressure thermal expansion coefficient GaAs-on-Si elastic strain annealing photoluminescence strain-free

项目摘要

In order to fabricate long-life laser diodes, strain-free GaAs films on Si substrates which were formed by annealing under ultrahigh pressure, were first characterized using X-ray diffraction (XRD) analysis and photoluminescence (PL) measurement. In the annealing method under ultrahigh pressure, the difference of the thermal expansion coefficient between a GaAs film and a Si substrate is expected to be compensated by that of the elastic strain generated by hydrostatic pressure.It was found that a strain-free GaAs film was formed on a Si substrate without serious degradation of the optical and crystallographical proterties of the film.It was also found that no additional strain or defects were generated during PL measuremet at 77 K.Next, the strain-free GaAs-on-Si structure was reannealed at atmospheric pressure, and variation of the strain was investigated. It was found in this experiment that the strain in the GaAs film increased rapidly in the first 5 min of reannealing but within 20 to 30 min it reached to a constant value which was determined by the reannealing temperature. Finally, both XRD and PL data were compared and an interesting result on the depth distribution of strain in a GaAs film was derived.Based on the above characterization, the residual strain in light emitting diodes with a (In, Ga)P/GaAs/Si structure was reduced by applying an appropriate pressure to the diodes, and the photo-and electoluminescence measurements were conducted. It was found from XRD analysis that the residual strain in the GaAs film was completely relaxd. PL measurements showed that the strain in the (In, Ga)P film was also relaxd partially. We conclude from these results that the annealing method under ultrahigh pressre is good enough for fabrication of oprical devices in heteroepitaxial structures.

为了制造长寿命的激光二极管，首先使用 X 射线衍射 (XRD) 分析和光致发光 (PL) 测量对通过超高压退火形成的 Si 衬底上的无应变 GaAs 薄膜进行表征。在超高压退火方法中，GaAs薄膜和Si衬底之间的热膨胀系数差异有望通过静水压力产生的弹性应变来补偿。在Si衬底上形成的GaAs-on-Si结构没有严重降低薄膜的光学和晶体学性能。还发现在77 K下进行PL测量时没有产生额外的应变或缺陷。接下来，无应变的GaAs-on-Si结构在大气压下进行再退火，并研究应变的变化。实验发现，GaAs薄膜中的应变在再退火的前5分钟内迅速增加，但在20至30分钟内达到恒定值，该恒定值由再退火温度决定。最后，比较了 XRD 和 PL 数据，得出了 GaAs 薄膜中应变深度分布的有趣结果。基于上述表征，具有 (In, Ga)P/GaAs/ 的发光二极管中的残余应变通过对二极管施加适当的压力来减少硅结构，并进行光致发光和电致发光测量。 XRD分析发现GaAs薄膜中的残余应变完全松弛。 PL测量表明(In,Ga)P薄膜中的应变也部分松弛。我们从这些结果得出结论，超高压力下的退火方法足以用于异质外延结构中光学器件的制造。