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Step instability of the In0.2Ga0.8As (001) surface during annealing

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Chinese Physics B 2012年第4期21卷 573-579页

作者：张毕禅周勋罗子江郭祥丁召 Low-Dimensional Semiconductor Structure Laboratory College of Science Guizhou University Guiyang 550025 China

Anisotropic evolution of the step edges on the compressive-strained In0.2Ga0.8 As/GaAs(001) surface has been investigated by scanning tunneling microscopy (STM). The experiments suggest that step edges are indeed sinuous and protrude somewhere a little way along the [110] direction, which is different from the classical waviness predicted by the theoretical model. We consider that the monatomic step edges undergo a morphological instability induced by the anisotropic diffusion of adatoms on the terrace during annealing, and we improve a kinetic model of step edge based on the classical Burton–Cabrera–Frank (BCF) model in order to determine the normal velocity of step enlargement. The results show that the normal velocity is proportional to the arc length of the peninsula, which is consistent with the first result of our kinetic model. Additionally, a significant phenomenon is an excess elongation along the [110] direction at the top of the peninsula with a higher aspect ratio, which is attributed to the restriction of diffusion lengths.

关键词： InGaAs step instability surface diffusion kinetic model

An application of half-terrace model to surface ripening of non-bulk GaAs layers

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Chinese Physics B 2014年第4期23卷 492-495页

作者：刘珂郭祥周清张毕禅罗子江丁召 College of Electronics and Information Guizhou University

In order to predict the actual quantity of non-bulk GaAs layers after long-time homoepitaxy on GaAs （001） by theo- retical calculation, a half-terrace diffusion model based on thermodynamics is used to calculate the ripening time of GaAs layers to form a fiat morphology in annealing. To verify the accuracy of the calculation, real space scanning tunneling microscopy images of GaAs surface after different annealing times are obtained and the roughness of the GaAs surface is measured. The results suggest that the half terrace model is an accurate method with a relative error of about 4.1%.

关键词： scanning tunneling microscopy III-V semiconductors annealing diffusion in nanoscale solids

In_(0.14)Ga_(0.86)As/GaAs(4×3)表面的RHEED及STM分析

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真空科学与技术学报 2012年第3期32卷 256-262页

作者：尚林涛罗子江周勋郭祥张毕禅何浩贺业全丁召贵州大学理学院贵阳550025 贵州省微纳电子与软件技术重点实验室贵阳550025

以在UHV/MBE-STM联合系统上生长的19ML的InGaAs/GaAs样品为研究对象,先在GaAs(001)衬底上外延生长0.37μm的GaAs缓冲层,再外延生长19ML的InGaAs,通过样品生长速率大致确定其组分为In0.14Ga0.86As,通过反射式高能电子衍射(RHEED)及扫描... 详细信息

以在UHV/MBE-STM联合系统上生长的19ML的InGaAs/GaAs样品为研究对象,先在GaAs(001)衬底上外延生长0.37μm的GaAs缓冲层,再外延生长19ML的InGaAs,通过样品生长速率大致确定其组分为In0.14Ga0.86As,通过反射式高能电子衍射(RHEED)及扫描隧道显微镜分析发现其表面主要由占大多数的4×3及少量的α2(2×4)重构混合而成,并用软件模拟RHEED对实验结果进行了验证。

关键词：反射式高能电子衍射分子束外延扫描隧道显微镜InGaAs表面重构模拟

100-nm T-gate InAlAs/InGaAs InP-based HEMTs with f_T = 249 GHz and f_(max) = 415 GHz

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Chinese Physics B 2014年第3期23卷 613-618页

作者：汪丽丹丁芃苏永波陈娇张毕禅金智 Microware Devices and Integrated Circuits Department Key Laboratory of Microelectronics Device and Integrated TechnologyInstitute of Microelectronics Chinese Academy of Sciences

InA1As/InGaAs high electron mobility transistors （HEMTs） on an InP substrate with well-balanced cutoff frequency fT and maximum oscillation frequency frnax are reported. An InA1As/InGaAs HEMT with 100-nm gate length and gate width of 2 × 50 μm shows excellent DC characteristics, including full channel current of 724 mA/mm, extrinsic maximum transconductance *** of 1051 mS/mm, and drain-gate breakdown voltage BVDG of 5.92 V. In addition, this device exhibits fT = 249 GHz and fmax = 415 GHz. These results were obtained by fabricating an asymmetrically recessed gate and minimizing the parasitic resistances. The specific Ohmic contact resistance was reduced to 0.031 ***. Moreover, the fT obtained in this work is the highest ever reported in 100-nm gate length InA1As/InGaAs InP-based HEMTs. The outstanding ***, fT, fmax, and good BVDG make the device suitable for applications in low noise amplifiers, power amplifiers, and high speed circuits.

关键词： InP high electron mobility transistor asymmetrically recessed gate cutoff frequency fx maximumoscillation frequency fmax

InAs薄膜的分子束外延生长与表面形貌及表面重构分析

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材料导报 2013年第4期27卷 90-92页

作者：王继红罗子江周勋张毕禅郭祥丁召贵州大学理学院贵阳550025 贵州财经学院教育管理学院贵阳550004 贵州师范大学物理与电子科学学院贵阳550001

利用带有反射高能电子衍射(RHEED)仪的分子束外延(MBE)方法,通过RHEED图像演变实时监控薄膜生长状况,采用RHEED强度振荡测量薄膜生长速率,在InAs(001)基片上同质外延InAs薄膜。利用扫描隧道显微镜(STM)对MBE生长的InAs薄膜表面形貌以及... 详细信息

利用带有反射高能电子衍射(RHEED)仪的分子束外延(MBE)方法,通过RHEED图像演变实时监控薄膜生长状况,采用RHEED强度振荡测量薄膜生长速率,在InAs(001)基片上同质外延InAs薄膜。利用扫描隧道显微镜(STM)对MBE生长的InAs薄膜表面形貌以及表面重构进行扫描分析,证实样品表面为原子级平整,并指出样品表面处于β2(2×4)与α2(2×4)两种重构混合的重构相。

关键词： InAs薄膜分子束外延反射高能电子衍射扫描隧道显微镜表面重构

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InAs(001)表面金属化的转变

材料导报 2012年第12期26卷 101-104,113页

作者：尚林涛周勋罗子江张毕禅郭祥丁召贵州大学理学院贵州省微纳电子与软件技术重点实验室贵阳550025

论述了利用分子束外延方法在InAs(001)基片上生长InAs时,样品表面由富As的(2×4)向富In的(4×2)转变的现象。通过控制生长参数生长出了较好的富As(2×4)表面。在As压不足的情况下,轻微的提升样品衬底温度,样品表面逐渐转向富In表面的(4... 详细信息

论述了利用分子束外延方法在InAs(001)基片上生长InAs时,样品表面由富As的(2×4)向富In的(4×2)转变的现象。通过控制生长参数生长出了较好的富As(2×4)表面。在As压不足的情况下,轻微的提升样品衬底温度,样品表面逐渐转向富In表面的(4×2)结构,呈现出(3×1)混合相。通过实验分析及软件模拟确定表面(4×2)结构区域已覆盖多达90%,表明样品表面大部分已金属化。

关键词： RHEED MBE STM InAs表面重构模拟

Surface segregation of InGaAs films by the evolution of reflection high-energy electron diffraction patterns

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Chinese Physics B 2012年第4期21卷 428-431页

作者：周勋罗子江郭祥张毕禅尚林涛周清邓朝勇丁召 College of Science Guizhou UniversityGuiyang 550025China School of Physics and Electronics Science Guizhou Normal UniversityGuiyang 550001China School of Education Administration Guizhou College of Finance and EconomicsGuiyang 550004China

Surface segregation is studied via the evolution of reflection high-energy electron diffraction （RHEED） patterns under different values of As4 BEP for InGaAs films. When the As4 BEP is set to be zero, the RHEED pattern keeps a 4x3/（nx3） structure with increasing temperature, and surface segregation takes place until 470 ℃ The RHEED pattern develops into a metal-rich （4x2） structure as temperature increases to 495℃. The reason for this is that surface segregation makes the In inside the InGaAs film climb to its surface. With the temperature increasing up to 515℃, the RHEED pattern turns into a GaAs（2x4） structure due to In desorption. While the As4 BEP comes up to a specific value （1.33 x 10-4 Pa-1.33 x 10-3 Pa）, the surface temperature can delay the segregation and desorption. We find that As4 BEP has a big influence on surface desorption, while surface segregation is more strongly dependent on temperature than surface desorption.

关键词： reflection high-energy electron diffraction InGaAs films surface segregation surface desorption

Step instability of the surface during *** （001） annealing

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Chinese Physics B 2012年第4期21卷 569-575页

作者：张毕禅周勋罗子江郭祥丁召 Low-Dimensional Semiconductor Structure Laboratory College of ScienceGuizhou UniversityGuiyang 550025China

Anisotropic evolution of the step edges on the compressive-strained In0.2Ga0.8As/GaAs（001） surface has been investigated by scanning tunneling microscopy （STM）. The experiments suggest that step edges are indeed sinuous and protrude somewhere a little way along the [110] direction, which is different from the classical waviness predicted by the theoretical model. We consider that the monatomic step edges undergo a morphological instability induced by the anisotropic diffusion of adatoms on the terrace during annealing, and we improve a kinetic model of step edge based on the classical Burton Cabrer-Frank （BCF） model in order to determine the normal velocity of step enlargement. The results show that the normal velocity is proportional to the arc length of the peninsula, which is consistent with the first result of our kinetic model. Additionally, a significant phenomenon is an excess elongation along the [110] direction at the top of the peninsula with a higher aspect ratio, which is attributed to the restriction of diffusion lengths.

关键词： InGaAs step instability surface diffusion kinetic model

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InP基三端太赫兹固态电子器件和电路发展

太赫兹科学与电子信息学报 2013年第1期 43-49页

作者：金智苏永波张毕禅丁芃汪丽丹周静涛杨成樾刘新宇中国科学院微电子研究所

随着微电子技术的飞速发展,半导体器件的截止频率已经进入到太赫兹频段,太赫兹电路的频率特性得到极大发展。以固态器件为基础的太赫兹电路的工作频率进入到THz频段。本文重点介绍InP基双极器件和场效应器件的发展以及在太赫兹电路和系... 详细信息

随着微电子技术的飞速发展,半导体器件的截止频率已经进入到太赫兹频段,太赫兹电路的频率特性得到极大发展。以固态器件为基础的太赫兹电路的工作频率进入到THz频段。本文重点介绍InP基双极器件和场效应器件的发展以及在太赫兹电路和系统中的应用。

关键词：太赫兹 InP基晶体管固态电子器件太赫兹单片集成电路