Ultrahigh Electron Mobilities in Si1-xGex/Si/Si1-xGex Heterostructures with Abrupt Interfaces Formed by Solid-Phase Epitaxy
Ultrahigh Electron Mobilities in Si1-xGex/Si/Si1-xGex Heterostructures with Abrupt Interfaces Formed by Solid-Phase Epitaxy
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固相外延形成突变界面的 Si1-xGex/Si/Si1-xGex 异质结构中的超高电子迁移率
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
M. Miyao
中科院分区：
文献类型：
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作者：
N. Sugii;K. Nakagawa;Y. Kimura;S. Yamaguchi;M. Miyao
采用分子束外延和固相外延相结合的方法成功制备了具有平坦通道的Si1-xGex/Si/Si1-xGex异质结构。固相外延生长完全抑制了通道层和掺杂层之间的锗偏析。透射电镜图像显示，错配位错仅限于缓冲层底部和衬底，异质界面非常光滑平坦。有梯度缓冲层的样品的电子迁移率比没有缓冲层的样品高近一个数量级。在15 K时，具有分级缓冲层（x=0.2）的样品获得了8.0×105 cm2V-1s-1的超高迁移率。
Si1-xGex/Si/Si1-xGex heterostructures with a flat channel were successfully fabricated by molecular-beam epitaxy combined with solid-phase epitaxy. The solid-phase epitaxial growth completely suppressed Ge segregation between the channel layer and the doped layer. Cross-sectional transmission-electron-microscope images revealed that misfit dislocations were limited to the bottom part of the buffer layer and to the substrate, and that the heterointerfaces were very smooth and flat. The electron mobility for a sample with a graded buffer layer was nearly one order of magnitude higher than without such a layer. Ultrahigh mobility of 8.0×105 cm2V-1s-1 was obtained at 15 K for a sample with a graded buffer layer (x=0.2).