Growth Mechanism of GaAs Microdisk Structures by Area-Selective Epitaxy Using Migration-Enhanced Epitaxy
Growth Mechanism of GaAs Microdisk Structures by Area-Selective Epitaxy Using Migration-Enhanced Epitaxy
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DOI：
10.1143/jjap.46.514
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发表时间：
2007-02
影响因子：
1.5
通讯作者：
Takayuki Iwai;T. Toda;T. Uehara;I. Yoshiba;Y. Horikoshi
中科院分区：
文献类型：
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作者：
Takayuki Iwai;T. Toda;T. Uehara;I. Yoshiba;Y. Horikoshi
我们已经进行了区域选择性外延的GaAs微盘结构的SiO2掩蔽的GaAs衬底上的迁移增强外延。我们已经成功地在590 °C下生长出“无损伤”的磁盘。研究发现，对于生长在（111）B衬底上的结构，圆盘周围的小平面受V/III束流等效压强比的控制。这种特性是由在高V/III比下[111]B方向上的降低的生长速率引起的。采用优化的生长条件，生长出了由六个垂直{110}面和平坦的（111）B顶包围的均匀六边形GaAs圆盘。然而，在（001）衬底上生长的微盘没有显示出平顶结构，与V/III比无关，这可能是由于（001）方向上的生长速率对V/III比不敏感的事实。在后一种情况下，获得了由四个倾斜的{011}面包围的正方锥体结构。
We have carried out area-selective epitaxy of GaAs microdisk structures on a SiO2-masked GaAs substrate by migration-enhanced epitaxy. We have successfully grown “damage-free” disks at 590 °C. It is found that, for the structures grown on (111)B substrates, the facets surrounding the disks are controlled by the V/III beam equivalent pressure ratio. This characteristic is caused by the reduced growth rate in the [111]B direction under high V/III ratios. Using an optimized growth condition, uniform hexagonal GaAs disks surrounded by six vertical {110} facets and a flat (111)B top are grown. The microdisks grown on (001) substrates, however, show no flat-top structures, regardless of the V/III ratio, probably due to the fact that the growth rate in the (001) direction is not sensitive to the V/III ratio. In the latter case, square-pyramidal structures surrounded by four inclined {011} facets are obtained.