硅缓冲层提高选区外延生长硅基锗薄膜质量
|
摘要
研究了Si缓冲层对选区外延Si基Ge薄膜的晶体质量的影响。利用超高真空化学气相沉积系统,结合低温Ge缓冲层和选区外延技术,通过插入Si缓冲层,在Si/SiO_2图形衬底上选择性外延生长Ge薄膜。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、原子力显微镜(AFM)表征了Ge薄膜的晶体质量和表面形貌。测试结果表明,选区外延Ge薄膜的晶体质量比无图形衬底外延得到薄膜的晶体质量要高;选区外延Ge薄膜前插入Si缓冲层得到Ge薄膜具有较低的XRD曲线半高宽以及表面粗糙度,位错密度低至5.9×10~5/cm~2,且薄膜经过高低温循环退火后,XRD曲线半高宽和位错密度进一步降低。通过插入Si缓冲层可提高选区外延Si基Ge薄膜的晶体质量,该技术有望应用于Si基光电集成。
The effect of Si buffer layer on the crystal quality of selective area epitaxy Ge film on Si substrate was studied. Combining with the low temperature Ge buffer layer and selective area epitaxy technology, by inserting Si buffer layer, Ge film on patterned Si/SiO_2 substrate was grown selectively by using ultra-high vacuum chemical vapor deposition. By X-ray diffraction(XRD), scanning electron microscope(SEM)and atomic force microscope(AFM), the crystal quality and surface morphology of Ge film were characterized. The results show that the crystal quality of Ge film based on selective area epitaxy technology is better than that of the epitaxial film grown on no-patterned substrate. By inserting Si buffer layer before selective area epitaxy Ge film, the Ge film grown selectively owns lower full-width-at-half maximum of the XRD profile and lower surface roughness. And the dislocation density of the Ge film is low to 5.9×10~5/cm~2.Moreover, the full-width-at-half maximum of the XRD profile and dislocation density of Ge film were reduced after high-low temperature cycle annealing. In conclusion, by using inserting silicon buffer layer, the crystal quality of selective area epitaxy Ge film on Si can be improved,which will be a promising method for Si-based optoelectronic integration.
The effect of Si buffer layer on the crystal quality of selective area epitaxy Ge film on Si substrate was studied. Combining with the low temperature Ge buffer layer and selective area epitaxy technology, by inserting Si buffer layer, Ge film on patterned Si/SiO_2 substrate was grown selectively by using ultra-high vacuum chemical vapor deposition. By X-ray diffraction(XRD), scanning electron microscope(SEM)and atomic force microscope(AFM), the crystal quality and surface morphology of Ge film were characterized. The results show that the crystal quality of Ge film based on selective area epitaxy technology is better than that of the epitaxial film grown on no-patterned substrate. By inserting Si buffer layer before selective area epitaxy Ge film, the Ge film grown selectively owns lower full-width-at-half maximum of the XRD profile and lower surface roughness. And the dislocation density of the Ge film is low to 5.9×10~5/cm~2.Moreover, the full-width-at-half maximum of the XRD profile and dislocation density of Ge film were reduced after high-low temperature cycle annealing. In conclusion, by using inserting silicon buffer layer, the crystal quality of selective area epitaxy Ge film on Si can be improved,which will be a promising method for Si-based optoelectronic integration.
引文
[1] LIN G Y, WANG C, LI C,et al.Strong electroluminescence from direct band and defects in Ge n+/p shallow junctions at room temperature[J]. Applied Physics Letters, 2016, 108(19):191107-1-191107-5.
[2] COLACE L, MASINI G, GALLUZZI F,et al. Metal-semiconductor-metal near-infrared light detector based on epitaxial Ge/Si[J]. Applied Physics Letters, 1998, 72(24):3175-3177.
[3] 王尘,许怡红,李成,等. 高性能SOI基Ge PIN波导光电探测器的制备及特性研究[J]. 物理学报,2017,66(19):198502-1-198502-6. WANG C, XU Y H, LI C,et al.Fabrication and cha-racteristics of high performance SOI-based Ge PIN waveguide photodetector[J].Acta Physica Sinica,2017, 66(19): 198502-1-198502-6 (in Chinese).
[4] MICHEL J, LIU J F, KIMERLING L C.High-performance Ge-on-Si photodetectors[J]. Nature Photonics, 2000, 4(8):527-534.
[5] NISHIOKA K, TAKAMOTO T, AGUI T, et al. Evaluation of InGaP/InGaAs/Ge triple-junction solar cell and optimization of solar cell's structure focusing on series resistance for high-efficiency concentrator photovoltaic systems [J]. Solar Energy Materials and Solar Cells, 2006, 90(9):1308-1321.
[6] ARAKAWA Y, NAKAMURA T, URINO Y, et al. Silicon photonics for next generation system integration platform[J]. IEEE Communications Magazine, 2013, 51(3):72-77.
[7] CURRIE M T, SAMAVEDAM S B, LANGDO T A, et al. Controlling threading dislocation densities in Ge on Si using graded SiGe layers and chemical-mechanical poli-shing[J]. Applied Physics Letters, 1998, 72(14):1718-1720.
[8] LUAM H C, LIM D R, LEE K K, et al. High-quality Ge epilayers on Si with low threading-dislocation densities[J]. Applied Physics Letters, 1999, 75(19):2909-2911.
[9] 陈城钊,郑元宇,黄诗浩,等. 硅基低位错密度厚锗外延层的UHV/CVD法生长[J]. 物理学报,2012, 61(7):078104-1-078104-5.CHEN C Z, ZHENG Y Y, HUANG S H, et al.Epitaxial growth of thick Ge layers with lowdislocation density on silicon substrate by UHV/CVD [J]. Acta Physica Sinica, 2012, 61(7): 078104-1-078104-5(in Chinese).
[10] LANGDO T A, LEITZ C W, CURRIE M T, et al. High quality Ge on Si by epitaxial necking[J]. Applied Physics Letters, 2000, 76(25):3700-3702.
[11] 汪建元,王尘,李成,等. 硅基锗薄膜选区外延生长研究[J]. 物理学报,2015,64(12):128102-1-128102-5.WANG J Y, WANG C, LI C, et al.Selective area growth of Ge film on Si[J]. Acta Physica Sinica, 2015, 64(12):128102-1-128102-5 (in Chinese).
[12] VANAMU G, DATYE A K, ZAIDI S H. Epitaxial growth of high-quality Ge films on nanostructured silicon substrates[J]. Applied Physics Letters, 2006, 88(20): 204104-1-204104-3.
[13] LI C, CHEN Y H, ZHOU Z W, et al. Enhanced photoluminescence of strained Ge with a δ-doping SiGe layer on silicon and silicon-on-insulator[J]. Applied Physics Letters, 2009, 95(25): 251102-1-251102-4.
[14] COLACE L, MASINI G, ASSANTO G, et al. Efficient high-speed near-infrared Ge photodetectors integrated on Si substrates [J]. Applied Physics Letters, 2000, 76(10):1231-1233.
[15] HALBWAX M, ROUVIERE M, ZHENG Y, et al. UHV-CVD growth and annealing of thin fully relaxed Ge films on (001)Si[J]. Optical Materials, 2005, 27(5):822-826.
[16] YU H Y, CHENG S L, PARK J H, et al. High quality single-crystal germanium-on-insulator on bulk Si substrates based on multistep lateral over-growth with hydrogen annealing[J]. Applied Physics Letters, 2010, 97(6): 063503-1-063503-4.
[17] YU H Y, PARK J H, OKYAY A K, et al. Selective-area high-quality germanium growth for monolithic integrated optoelectronics[J]. IEEE Electron Device Letters, 2012, 33(4):579-581.
[2] COLACE L, MASINI G, GALLUZZI F,et al. Metal-semiconductor-metal near-infrared light detector based on epitaxial Ge/Si[J]. Applied Physics Letters, 1998, 72(24):3175-3177.
[3] 王尘,许怡红,李成,等. 高性能SOI基Ge PIN波导光电探测器的制备及特性研究[J]. 物理学报,2017,66(19):198502-1-198502-6. WANG C, XU Y H, LI C,et al.Fabrication and cha-racteristics of high performance SOI-based Ge PIN waveguide photodetector[J].Acta Physica Sinica,2017, 66(19): 198502-1-198502-6 (in Chinese).
[4] MICHEL J, LIU J F, KIMERLING L C.High-performance Ge-on-Si photodetectors[J]. Nature Photonics, 2000, 4(8):527-534.
[5] NISHIOKA K, TAKAMOTO T, AGUI T, et al. Evaluation of InGaP/InGaAs/Ge triple-junction solar cell and optimization of solar cell's structure focusing on series resistance for high-efficiency concentrator photovoltaic systems [J]. Solar Energy Materials and Solar Cells, 2006, 90(9):1308-1321.
[6] ARAKAWA Y, NAKAMURA T, URINO Y, et al. Silicon photonics for next generation system integration platform[J]. IEEE Communications Magazine, 2013, 51(3):72-77.
[7] CURRIE M T, SAMAVEDAM S B, LANGDO T A, et al. Controlling threading dislocation densities in Ge on Si using graded SiGe layers and chemical-mechanical poli-shing[J]. Applied Physics Letters, 1998, 72(14):1718-1720.
[8] LUAM H C, LIM D R, LEE K K, et al. High-quality Ge epilayers on Si with low threading-dislocation densities[J]. Applied Physics Letters, 1999, 75(19):2909-2911.
[9] 陈城钊,郑元宇,黄诗浩,等. 硅基低位错密度厚锗外延层的UHV/CVD法生长[J]. 物理学报,2012, 61(7):078104-1-078104-5.CHEN C Z, ZHENG Y Y, HUANG S H, et al.Epitaxial growth of thick Ge layers with lowdislocation density on silicon substrate by UHV/CVD [J]. Acta Physica Sinica, 2012, 61(7): 078104-1-078104-5(in Chinese).
[10] LANGDO T A, LEITZ C W, CURRIE M T, et al. High quality Ge on Si by epitaxial necking[J]. Applied Physics Letters, 2000, 76(25):3700-3702.
[11] 汪建元,王尘,李成,等. 硅基锗薄膜选区外延生长研究[J]. 物理学报,2015,64(12):128102-1-128102-5.WANG J Y, WANG C, LI C, et al.Selective area growth of Ge film on Si[J]. Acta Physica Sinica, 2015, 64(12):128102-1-128102-5 (in Chinese).
[12] VANAMU G, DATYE A K, ZAIDI S H. Epitaxial growth of high-quality Ge films on nanostructured silicon substrates[J]. Applied Physics Letters, 2006, 88(20): 204104-1-204104-3.
[13] LI C, CHEN Y H, ZHOU Z W, et al. Enhanced photoluminescence of strained Ge with a δ-doping SiGe layer on silicon and silicon-on-insulator[J]. Applied Physics Letters, 2009, 95(25): 251102-1-251102-4.
[14] COLACE L, MASINI G, ASSANTO G, et al. Efficient high-speed near-infrared Ge photodetectors integrated on Si substrates [J]. Applied Physics Letters, 2000, 76(10):1231-1233.
[15] HALBWAX M, ROUVIERE M, ZHENG Y, et al. UHV-CVD growth and annealing of thin fully relaxed Ge films on (001)Si[J]. Optical Materials, 2005, 27(5):822-826.
[16] YU H Y, CHENG S L, PARK J H, et al. High quality single-crystal germanium-on-insulator on bulk Si substrates based on multistep lateral over-growth with hydrogen annealing[J]. Applied Physics Letters, 2010, 97(6): 063503-1-063503-4.
[17] YU H Y, PARK J H, OKYAY A K, et al. Selective-area high-quality germanium growth for monolithic integrated optoelectronics[J]. IEEE Electron Device Letters, 2012, 33(4):579-581.