An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is introduced. SiGe alloys and SiGe/Si multiple quantum wells (MQWs) have been grown by cold-wall UHV/CVD using disilane (Si 2H 6) and germane (GeH 4) as ...An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is introduced. SiGe alloys and SiGe/Si multiple quantum wells (MQWs) have been grown by cold-wall UHV/CVD using disilane (Si 2H 6) and germane (GeH 4) as the reactant gases on Si (100) substrates. The growth rate and Ge contents in SiGe alloys are studied at different temperature and different gas flow. The growth rate of SiGe alloy is decreased with the increase of GeH 4 flow at high temperature. X-ray diffraction measurement shows that SiGe/Si MQWs have good crystallinity, sharp interface and uniformity. No dislocation is found in the observation of transmission electron microscopy (TEM) of SiGe/Si MQWs. The average deviation of the thickness and the fraction of Ge in single SiGe alloy sample are 3.31% and 2.01%, respectively.展开更多
Using double crystal X-rays diffraction (DCXRD) and atomic force microscopy (AFM), the results of Ge x Si 1- x grown by UHV/CVD from Si 2H 6 and SiH 4 are analyzed and compared. Adsorbates can migrate to the energy-fa...Using double crystal X-rays diffraction (DCXRD) and atomic force microscopy (AFM), the results of Ge x Si 1- x grown by UHV/CVD from Si 2H 6 and SiH 4 are analyzed and compared. Adsorbates can migrate to the energy-favoring position due to the slow growth rate from SiH 4. In this case, a Si buffer that isolates the effect of substrate on epilayer could not be grown, which results in a pit penetrating into epilayer and buffer. The FWHM is 0.055° in DCXRD from SiH 4. The presence of diffraction fringes is an indication of an excellent crystalline quality. The roughness of the surface is improved if grown by Si 2H 6; however, the crystal quality of the Ge x Si 1- x material became worse than that from SiH 4 due to much larger growth rate from Si 2H 6. The content of Ge is obtained from DCXRD, which indicates the growth rate from Si 2H 6 is largest, then GeH 4, and that from SiH 4 is least.展开更多
基金ChineseHigh -TechnologyResearchPlan (No .863- 30 7- 15- 4 ( 0 3) )andChineseNaturalScienceFund (No .698962 60 )
文摘An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is introduced. SiGe alloys and SiGe/Si multiple quantum wells (MQWs) have been grown by cold-wall UHV/CVD using disilane (Si 2H 6) and germane (GeH 4) as the reactant gases on Si (100) substrates. The growth rate and Ge contents in SiGe alloys are studied at different temperature and different gas flow. The growth rate of SiGe alloy is decreased with the increase of GeH 4 flow at high temperature. X-ray diffraction measurement shows that SiGe/Si MQWs have good crystallinity, sharp interface and uniformity. No dislocation is found in the observation of transmission electron microscopy (TEM) of SiGe/Si MQWs. The average deviation of the thickness and the fraction of Ge in single SiGe alloy sample are 3.31% and 2.01%, respectively.
基金The National Natural Science Foundation of China
文摘Using double crystal X-rays diffraction (DCXRD) and atomic force microscopy (AFM), the results of Ge x Si 1- x grown by UHV/CVD from Si 2H 6 and SiH 4 are analyzed and compared. Adsorbates can migrate to the energy-favoring position due to the slow growth rate from SiH 4. In this case, a Si buffer that isolates the effect of substrate on epilayer could not be grown, which results in a pit penetrating into epilayer and buffer. The FWHM is 0.055° in DCXRD from SiH 4. The presence of diffraction fringes is an indication of an excellent crystalline quality. The roughness of the surface is improved if grown by Si 2H 6; however, the crystal quality of the Ge x Si 1- x material became worse than that from SiH 4 due to much larger growth rate from Si 2H 6. The content of Ge is obtained from DCXRD, which indicates the growth rate from Si 2H 6 is largest, then GeH 4, and that from SiH 4 is least.
