在超高真空化学气相沉积设备上,利用低温生长的硅锗和锗作为缓冲层,在SOI衬底上成功外延出高质量的锗薄膜.基于谐振腔增强型探测器(RCE)理论,模拟优化了有源层和上下反射层的厚度尺寸.传输矩阵方法计算结果显示:将SOI衬底自有二氧化硅...在超高真空化学气相沉积设备上,利用低温生长的硅锗和锗作为缓冲层,在SOI衬底上成功外延出高质量的锗薄膜.基于谐振腔增强型探测器(RCE)理论,模拟优化了有源层和上下反射层的厚度尺寸.传输矩阵方法计算结果显示:将SOI衬底自有二氧化硅、硅层作为一对下反射层的情况下,取2对SiO_2/Ta_2O_5作为上反射层时,量子效率可以达到接近56%.制作的SOI基锗光电探测器,暗电流密度为0.65 m A·cm^(-2).在8 V的偏压下,探测器在1 550 nm处响应度1.45 m A·W^(-1),可以观察到探测器的共振现象.展开更多
High-performance and tensile-strained germanium(Ge) p-i-n photodetector is demonstrated on Si substrate. The epitaxial Ge layers were prepared in an ultrahigh vacuum chemical vapor deposition(UHV-CVD) system using low...High-performance and tensile-strained germanium(Ge) p-i-n photodetector is demonstrated on Si substrate. The epitaxial Ge layers were prepared in an ultrahigh vacuum chemical vapor deposition(UHV-CVD) system using low temperature Ge buffer technique. The devices were fabricated by in situ doping and using Si as passivation layer between Ge and metal, which can improve the ohmic contact and realize the high doping. The results show that the dark current of the photodetector with diameter of 24 μm is about 2.5×10^(-7) μA at the bias voltage of –1 V, and the optical responsivity is 0.1 A/W at wavelength of 1.55 μm. The 3 dB bandwidth(BW) of 4 GHz is obtained for the photodetector with diameter of 24 μm at reverse bias voltage of 1 V. The long diffusion time of minority carrier in n-type Ge and the large contact resistance in metal/Ge contacts both affect the performance of Ge photodetectors.展开更多
The tensile strained Ge/SiGe multiple quantum wells(MQWs) grown on a silicon-on-insulator(SOI) substrate were fabricated successfully by ultra-high chemical vapor deposition.Room temperature direct band photoluminesce...The tensile strained Ge/SiGe multiple quantum wells(MQWs) grown on a silicon-on-insulator(SOI) substrate were fabricated successfully by ultra-high chemical vapor deposition.Room temperature direct band photoluminescence from Ge quantum wells on SOI substrate is strongly modulated by Fabry-Perot cavity formed between the surface of Ge and the interface of buried SiO2.The photoluminescence peak intensity at 1.58 μm is enhanced by about 21 times compared with that from the Ge/SiGe quantum wells on Si substrate,and the full width at half maximum(FWHM) is significantly reduced.It is suggested that tensile strained Ge/SiGe multiple quantum wells are one of the promising materials for Si-based microcavity light emitting devices.展开更多
文摘在超高真空化学气相沉积设备上,利用低温生长的硅锗和锗作为缓冲层,在SOI衬底上成功外延出高质量的锗薄膜.基于谐振腔增强型探测器(RCE)理论,模拟优化了有源层和上下反射层的厚度尺寸.传输矩阵方法计算结果显示:将SOI衬底自有二氧化硅、硅层作为一对下反射层的情况下,取2对SiO_2/Ta_2O_5作为上反射层时,量子效率可以达到接近56%.制作的SOI基锗光电探测器,暗电流密度为0.65 m A·cm^(-2).在8 V的偏压下,探测器在1 550 nm处响应度1.45 m A·W^(-1),可以观察到探测器的共振现象.
基金supported by the National Natural Science Foundation of China(Nos.61474094 and 61176092)
文摘High-performance and tensile-strained germanium(Ge) p-i-n photodetector is demonstrated on Si substrate. The epitaxial Ge layers were prepared in an ultrahigh vacuum chemical vapor deposition(UHV-CVD) system using low temperature Ge buffer technique. The devices were fabricated by in situ doping and using Si as passivation layer between Ge and metal, which can improve the ohmic contact and realize the high doping. The results show that the dark current of the photodetector with diameter of 24 μm is about 2.5×10^(-7) μA at the bias voltage of –1 V, and the optical responsivity is 0.1 A/W at wavelength of 1.55 μm. The 3 dB bandwidth(BW) of 4 GHz is obtained for the photodetector with diameter of 24 μm at reverse bias voltage of 1 V. The long diffusion time of minority carrier in n-type Ge and the large contact resistance in metal/Ge contacts both affect the performance of Ge photodetectors.
基金supported by the National Natural Science Foundation of China(Nos.61036003 and 61176092)the Ph.D.Programs Foundation of Ministry of Education of China(No.20110121110025)
文摘The tensile strained Ge/SiGe multiple quantum wells(MQWs) grown on a silicon-on-insulator(SOI) substrate were fabricated successfully by ultra-high chemical vapor deposition.Room temperature direct band photoluminescence from Ge quantum wells on SOI substrate is strongly modulated by Fabry-Perot cavity formed between the surface of Ge and the interface of buried SiO2.The photoluminescence peak intensity at 1.58 μm is enhanced by about 21 times compared with that from the Ge/SiGe quantum wells on Si substrate,and the full width at half maximum(FWHM) is significantly reduced.It is suggested that tensile strained Ge/SiGe multiple quantum wells are one of the promising materials for Si-based microcavity light emitting devices.
