Fifteen periods of Si/Si_(0.7)Ge_(0.3)multilayers(MLs)with various Si Ge thicknesses are grown on a 200 mm Si substrate using reduced pressure chemical vapor deposition(RPCVD).Several methods were utilized to characte...Fifteen periods of Si/Si_(0.7)Ge_(0.3)multilayers(MLs)with various Si Ge thicknesses are grown on a 200 mm Si substrate using reduced pressure chemical vapor deposition(RPCVD).Several methods were utilized to characterize and analyze the ML structures.The high resolution transmission electron microscopy(HRTEM)results show that the ML structure with 20 nm Si_(0.7)Ge_(0.3)features the best crystal quality and no defects are observed.Stacked Si_(0.7)Ge_(0.3)ML structures etched by three different methods were carried out and compared,and the results show that they have different selectivities and morphologies.In this work,the fabrication process influences on Si/Si Ge MLs are studied and there are no significant effects on the Si layers,which are the channels in lateral gate all around field effect transistor(L-GAAFET)devices.For vertically-stacked dynamic random access memory(VS-DRAM),it is necessary to consider the dislocation caused by strain accumulation and stress release after the number of stacked layers exceeds the critical thickness.These results pave the way for the manufacture of high-performance multivertical-stacked Si nanowires,nanosheet L-GAAFETs,and DRAM devices.展开更多
The analysis of threading dislocation density （TDD） in Ge-on-Si layer is critical for developing lasers, light emitting diodes （LEDs）, photodetectors （PDs）, modulators, waveguides, metal oxide semiconductor fiel...The analysis of threading dislocation density （TDD） in Ge-on-Si layer is critical for developing lasers, light emitting diodes （LEDs）, photodetectors （PDs）, modulators, waveguides, metal oxide semiconductor field effect transistors （MOSFETs）, and also the integration of Si-based monolithic photonics. The TDD of Ge epitaxial layer is analyzed by etching or transmission electron microscope （TEM）. However, high-resolution x-ray diffraction （HR-XRD） rocking curve provides an optional method to analyze the TDD in Ge layer. The theory model of TDD measurement from rocking curves was first used in zinc-blende semiconductors. In this paper, this method is extended to the case of strained Ge-on-Si layers. The HR-XRD 2θ/ω scan is measured and Ge （004） single crystal rocking curve is utilized to calculate the TDD in strained Ge epitaxial layer. The rocking curve full width at half maximum （FWHM） broadening by incident beam divergence of the instrument, crystal size, and curvature of the crystal specimen is subtracted. The TDDs of samples A and B are calculated to be 1.41108 cm-2 and 6.47108 cm-2, respectively. In addition, we believe the TDDs calculated by this method to be the averaged dislocation density in the Ge epitaxial layer.展开更多
By using reduced pressure chemical vapor deposition (RPCVD), the high strained, Ge-graded SiGe film growth has been realized. The film was used as a base of the HBT (Heterojunction Bipolar Transistor) developed in 0....By using reduced pressure chemical vapor deposition (RPCVD), the high strained, Ge-graded SiGe film growth has been realized. The film was used as a base of the HBT (Heterojunction Bipolar Transistor) developed in 0.35 μm SiGe BiCMOS process technology, and made the device give good DC characteristics (β > 100) and high-frequency performance (fT = 67 GHz), thus meeting the requirements for technical specifications in 0.35 μm SiGe BiCMOS process technology.展开更多
This paper describes a method using both reduced pressure chemical vapor deposition （RPCVD） and ultrahigh vacuum chemical vapor deposition （UHVCVD） to grow a thin compressively strained Ge film. As the first step,...This paper describes a method using both reduced pressure chemical vapor deposition （RPCVD） and ultrahigh vacuum chemical vapor deposition （UHVCVD） to grow a thin compressively strained Ge film. As the first step, low temperature RPCVD was used to grow a fully relaxed SiGe virtual substrate layer at 500 ℃ with a thickness of 135 nm, surface roughness of 0.3 nm, and Ge content of 77%. Then, low temperature UHVCVD was used to grow a high quality strained pure Ge film on the SiGe virtual substrate at 300 ℃ with a thickness of 9 nm, surface roughness of 0.4 nm, and threading dislocation density of - 10^5 cm^-2. Finally, a very thin strained Si layer of 1.5-2 nm thickness was grown on the Ge layer at 550 ℃ for the purpose of passivation and protection. The whole epitaxial layer thickness is less than 150 nm. Due to the low growth temperature, the two-dimensional layer-by-layer growth mode dominates during the epitaxial process, which is a key factor for the growth of high quality strained Ge films.展开更多
为制备高性能硅(Si)基锗(Ge)外延材料,采用基于减压化学气相淀积系统(reduced pressure chemical vapor deposition,RPCVD)工艺的低温/高温(low temperature/high temperature,LT/HT)生长技术制备了厚度为1μm的Ge外延材料样品1、2,其中...为制备高性能硅(Si)基锗(Ge)外延材料,采用基于减压化学气相淀积系统(reduced pressure chemical vapor deposition,RPCVD)工艺的低温/高温(low temperature/high temperature,LT/HT)生长技术制备了厚度为1μm的Ge外延材料样品1、2,其中,LT阶段的生长温度为400~450℃,HT阶段的生长温度为700℃。通过原子力显微镜(atomic force microscope,AFM)测试得到样品1、2的材料表面粗糙度均方根(root mean square,RMS)分别为0.66、0.86 nm,样品表面光滑程度较好。同时,根据X射线衍射(X-ray diffraction,XRD)的测试结果得到样品1、2的应变度分别为0.21%、0.23%,Ge的衍射峰对称较好,表明材料结晶质量较高。通过对样品Ⅰ~Ⅳ进行热稳定性试验发现,在700℃条件下对Ge外延材料进行循环热退火,材料可以获得最好的晶体质量。展开更多
基金supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences (Project ID.XDA0330300)in part by Innovation Program for Quantum Science and Technology (Project ID.2021ZD0302301)in part by the Youth Innovation Promotion Association of CAS (Project ID.2020037)。
文摘Fifteen periods of Si/Si_(0.7)Ge_(0.3)multilayers(MLs)with various Si Ge thicknesses are grown on a 200 mm Si substrate using reduced pressure chemical vapor deposition(RPCVD).Several methods were utilized to characterize and analyze the ML structures.The high resolution transmission electron microscopy(HRTEM)results show that the ML structure with 20 nm Si_(0.7)Ge_(0.3)features the best crystal quality and no defects are observed.Stacked Si_(0.7)Ge_(0.3)ML structures etched by three different methods were carried out and compared,and the results show that they have different selectivities and morphologies.In this work,the fabrication process influences on Si/Si Ge MLs are studied and there are no significant effects on the Si layers,which are the channels in lateral gate all around field effect transistor(L-GAAFET)devices.For vertically-stacked dynamic random access memory(VS-DRAM),it is necessary to consider the dislocation caused by strain accumulation and stress release after the number of stacked layers exceeds the critical thickness.These results pave the way for the manufacture of high-performance multivertical-stacked Si nanowires,nanosheet L-GAAFETs,and DRAM devices.
基金Project supported by the Research Plan in Shaanxi Province,China(Grant No.2016GY-085)the Opening Project of Key Laboratory of Microelectronic Devices&Integrated Technology,Institute of Microelectronics,Chinese Academy of Sciences(Grant No.90109162905)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.17-H863-04-ZT-001-019-01)the National Natural Science Foundation of China(Grant Nos.61704130 and 61474085)
文摘The analysis of threading dislocation density （TDD） in Ge-on-Si layer is critical for developing lasers, light emitting diodes （LEDs）, photodetectors （PDs）, modulators, waveguides, metal oxide semiconductor field effect transistors （MOSFETs）, and also the integration of Si-based monolithic photonics. The TDD of Ge epitaxial layer is analyzed by etching or transmission electron microscope （TEM）. However, high-resolution x-ray diffraction （HR-XRD） rocking curve provides an optional method to analyze the TDD in Ge layer. The theory model of TDD measurement from rocking curves was first used in zinc-blende semiconductors. In this paper, this method is extended to the case of strained Ge-on-Si layers. The HR-XRD 2θ/ω scan is measured and Ge （004） single crystal rocking curve is utilized to calculate the TDD in strained Ge epitaxial layer. The rocking curve full width at half maximum （FWHM） broadening by incident beam divergence of the instrument, crystal size, and curvature of the crystal specimen is subtracted. The TDDs of samples A and B are calculated to be 1.41108 cm-2 and 6.47108 cm-2, respectively. In addition, we believe the TDDs calculated by this method to be the averaged dislocation density in the Ge epitaxial layer.
文摘By using reduced pressure chemical vapor deposition (RPCVD), the high strained, Ge-graded SiGe film growth has been realized. The film was used as a base of the HBT (Heterojunction Bipolar Transistor) developed in 0.35 μm SiGe BiCMOS process technology, and made the device give good DC characteristics (β > 100) and high-frequency performance (fT = 67 GHz), thus meeting the requirements for technical specifications in 0.35 μm SiGe BiCMOS process technology.
基金Project supported by the National Natural Science Foundation of China(Nos.60636010,60820106001)
文摘This paper describes a method using both reduced pressure chemical vapor deposition （RPCVD） and ultrahigh vacuum chemical vapor deposition （UHVCVD） to grow a thin compressively strained Ge film. As the first step, low temperature RPCVD was used to grow a fully relaxed SiGe virtual substrate layer at 500 ℃ with a thickness of 135 nm, surface roughness of 0.3 nm, and Ge content of 77%. Then, low temperature UHVCVD was used to grow a high quality strained pure Ge film on the SiGe virtual substrate at 300 ℃ with a thickness of 9 nm, surface roughness of 0.4 nm, and threading dislocation density of - 10^5 cm^-2. Finally, a very thin strained Si layer of 1.5-2 nm thickness was grown on the Ge layer at 550 ℃ for the purpose of passivation and protection. The whole epitaxial layer thickness is less than 150 nm. Due to the low growth temperature, the two-dimensional layer-by-layer growth mode dominates during the epitaxial process, which is a key factor for the growth of high quality strained Ge films.
文摘为制备高性能硅(Si)基锗(Ge)外延材料,采用基于减压化学气相淀积系统(reduced pressure chemical vapor deposition,RPCVD)工艺的低温/高温(low temperature/high temperature,LT/HT)生长技术制备了厚度为1μm的Ge外延材料样品1、2,其中,LT阶段的生长温度为400~450℃,HT阶段的生长温度为700℃。通过原子力显微镜(atomic force microscope,AFM)测试得到样品1、2的材料表面粗糙度均方根(root mean square,RMS)分别为0.66、0.86 nm,样品表面光滑程度较好。同时,根据X射线衍射(X-ray diffraction,XRD)的测试结果得到样品1、2的应变度分别为0.21%、0.23%,Ge的衍射峰对称较好,表明材料结晶质量较高。通过对样品Ⅰ~Ⅳ进行热稳定性试验发现,在700℃条件下对Ge外延材料进行循环热退火,材料可以获得最好的晶体质量。
