New dark current component of InGaAs／InP HPDs confirmed by DLTS

The dark current of In_(0.47) Ga_(0.53) As/InP heterojunction photodiodes (HPDs) was analysed. We found that there exists a new dark current component-deep level-assisted tunnelling current.DLTS was used to measure the In_(0.47)Ga_(0.53)As/InP HPDs. An electronic trap which has a thermal activation energy of O.44 eV, level concentration of 3.10×10^(13)cm^(-3) and electronic capture cross section of 1.72×10^(12)cm^2 has been found.It s existence results in the new tunnelling current.     

LP－MOCVD制作InGaAs／InPPIN光电二极管

采用ＬＰ－ＭＯＣＶＤ制作了ＩｎＧａＡｓ／ＩｎＰ平面型ＰＩＮ光电二极管。器件光敏面直径为７５μｍ，采用Ｚｎ扩散形成ＰＮ结，－６Ｖ偏置下其暗电流低达８～１３ｎＡ；反向击穿电压为６０Ｖ（１μＡ）。在没有增透膜时，对１．３μｍ注入光响应度为０．５６Ａ／Ｗ，光谱响应范围为０．９０～１．７０μｍ。     

In0.53Ga0.47As／InP异质结光电二极管的深能级

采用深能级瞬态谱仪（ＤＬＴＳ）测定了Ｉｎ０．５３Ｇａ０．４７Ａｓ／ＩｎＰ异质结光电二极管的ＤＬＴＳ谱。发现存在一电子陷阱，该陷阱能级位于导带底以下０．４４ｅＶ处，能级密度为３．１０×１０１３ｃｍ－３，电子俘获截面为１．７２×１０－１２ｃｍ－２。由于深能级的存在，导致了该器件存在一种新的“暗电流”──“深能级协助隧穿电流”。     

A low dark current InGaAs/InP p-i-n photodiode with covered mesa structure

A new InGaAs p-i-n photodiode with a covered mesa (CM) structure having extremely low dark current characteristics and high yields has been developed. The device consists of only two epitaxial layers: n^--InP and n^--InGaAs, continuously grown on an n⁺-InP substrate by liquid-phase epitaxy. The InGaAs layer is chemically etched to be a tapered shape in order to make the fabrication process simple, as compared with a conventional mesa diode. The Zn diffusion to form a p-n junction is carried out without a diffusion mask such as Si3N4or SiO2, which induces damage due to the thermal stress. The tapered-shape InGaAs layer is covered with the Zn-diffused layer because a surface p-n junction occurring in an InGaAs region is leaky. Therefore, the surface p-n junction of the photodiode appears in the n^--InP layer, which has a bandgap about two times wider than the InGaAs. Finally, the passivation of the surface p-n junction is carried out with a Si3N4film formed by a plasma-assisted chemical vapor deposition. We have successfully achieved an extremely low dark current of 20 pA at a reverse bias voltage of 10 V and a high yield of 80 percent, by adopting the CM structure and the simple fabrication process.     

Improvement of dark current using InP/InGaAsP transition layer in large-area InGaAs MSM photodetectors

A large-area InGaAs metal-semiconductor-metal (MSM) photodetector with 1/spl times/1 mm/sup 2/ photoactive area for free-space optical communication applications has been designed, fabricated, and characterized. Interdigitated electrodes of 2-/spl mu/m widths and 15-/spl mu/m spacings are designed to maximize the responsivity, and enable MSM photodetectors to reach a maximum responsivity at 1.53-/spl mu/m wavelength. By employing a two-step InP/InGaAsP transition layer, the dark current density of 45 fA//spl mu/m/sup 2/ was achieved at 10-V bias and at room temperature. Dark current-bias voltage curves were measured as a function of temperature from 40 to 270 K to estimate the activation energy. A 3-dB bandwidth of 210 MHz was obtained at a 10-V bias, and the measured result was compared with the designed bandwidth.     

SSPA周边杂散光对响应度不均匀性的影响

根据实验现象，用半导体光电效应的基本原理，定性分析了自扫描光电二极管列阵周边杂散光对响应度不均匀性的影响，从装置和列阵结构上提出了相应的改进措施，有效地解决了列阵首尾部分二极管响应度的不均匀性。     

GaAs MsM光电探测器暗电流特性

据根金属－半导体－金属光电探测器内的能带结构以及热电子发射与扩散理论相结合的模型，导出了ＭＳＭ光电探测器暗电流的计算公式，并用数据计算方法了不同距离和不同掺杂浓度与暗电流的关系，为设计低暗电流ＭＳＭ光电探测器提供了依据。     

InGaAs/InGaAsP/InP SAGM-APD器件设计考虑及I_P—V曲线二级阶梯状扭折

本文根据雪崩电场和限制隧道电流电场要求出发,设计和估算了InGaAs/InGaAsP/InPSAGM-APD器件参数,测量并解释了I_p-V曲线的二级阶梯扭折行为,指出了V_(th)/V_B以1/3左右为宜和与实际测量的M_p比较吻合的经验公式。     

Observation and study on the dark defects in InGaAsP/InP double-heterostructure leds

 The defects in lnGaAsP/InP DH LEDs are observed with an infrared line scanner.The dark structure appears before aging and it exists mainly in the form of dark spot defect.The effect of the variety and concentration of the doping for p-InP confining layers on the dark defects is studied.The results show that the percentage of devices with dark defects is much lower for Mg or In-Zn doped devices than for Zn doped devices.It is believed that Zn is one of the important origin for the formation of dark defects.The growth rate of dark defects is studied both at room temperature and at 70—85℃.The results show that after agin for 15000 h at room temperature there are no dark defects newly appeared.But after aging for 2000 h at 70—85℃ some devices show newly formed dark structure with very slow growth rate.     

LPE制作平面型InGaAs/InP APD

叙述了用液相外延(LPE)制作 InGaAsP/InP 雪崩光电二极管(APD)的物理性能。分析了该器件的设计参数。介绍了器件结构、器件制作中 LPE 生长条件及器件性能。最后,评述了器件发展水平及改进意见。     

New dark current suppression CMOS readout circuit with novel CDS structure for large format QWIP FPA

A new Dark Current Suppression (DCS) CMOS readout circuits for large format Quantum-Well-Infrared Photo-detector (QWIP) Focal-Plane-Array (FPA) with novel CorrelatedDouble-Sampling (CDS) structure based on dynamic source-follower are proposed, which can overcome the drawbacks of the present techniques, such as sensitive to the non-uniformity of the QWIP materials, poor readout noise features, low frame frequency, limited injection efficiency and dynamic range, etc. The dummy is adopted to realize dark current suppression, while the cascode current mirror (with current ratio of 1:10) can increase charge sensitivity and reduce integration time. Through the novel CDS structure, the output waveform is boxcar, and the frame frequency is increased. Simulation results demonstrate that, in high background sense, the proposed DCS circuit can suppress the dark current, achieve good readout performance, such as low power consumption, high charge sensitivity, high resolution, large dynamic range, and insensitive to the non-uniformity of the QWIP materials.     

一种InGaAs/InP复合沟道高电子迁移率晶体管模拟的新方法

采用一种新方法对InGaAs/InP复合沟道高电子迁移率晶体管进行了模拟.该方法通过流体力学模型和密度梯度模型的联合求解,得到了沟道内的电子密度分布.与一些传统方法相比,该方法收敛性更好,速度更快,且同样适用于其他类型高电子迁移率晶体管器件的模拟.利用仿真对InGaAs/InP复合沟道高电子迁移率晶体管进行了深入研究.     

InGaAs/InP材料的MOCVD生长研究

研究了InGaAs/InP材料的MOCVD生长技术和材料的性能特征。InP衬底的晶向偏角能够明显影响外延生长模型以及外延层的表面形貌,用原子力显微镜(AFM)观察到了外延层表面原子台阶的聚集现象(step-bunching现象),通过晶体表面的原子台阶密度和二维生长模型解释了台阶聚集现象的形成。对外延材料进行化学腐蚀,通过双晶X射线衍射(DCXRD)分析发现异质结界面存在应力,用异质结界面岛状InAs富集解释了应力的产生。通过严格控制InGaAs材料的晶格匹配,并优化MOCVD外延生长工艺,制备出厚层InGaAs外延材料,获得了低于1×1015cm-3的背景载流子浓度和良好的晶体质量。     

用于粒子场图像速度分析的新型光源装置

介绍了一种用于粒子图像速度分析（ＰＩＶ）的光源装置。利用该装置可在间得到一组相互平行的“光切面”，用于精确、快速地对复杂流场分布进行分析。     

一种InGaAs/InP复合沟道高电子迁移率晶体管模拟的新方法

采用一种新方法对InGaAs/InP复合沟道高电子迁移率晶体管进行了模拟.该方法通过流体力学模型和密度梯度模型的联合求解,得到了沟道内的电子密度分布.与一些传统方法相比,该方法收敛性更好,速度更快,且同样适用于其他类型高电子迁移率晶体管器件的模拟.利用仿真对InGaAs/InP复合沟道高电子迁移率晶体管进行了深入研究.     

InGaAsP／InP异质结光电三极管的制备

介绍了ｎ－ＩｎＰ／ｐ－ＩｎＧａＡｓＰ／０－ＩｎＰ结构的异质结光电三极管制作过程，并获得了对１．３μｍ的入射光，光增益达２２０，用带尾纤的ＧａＡｓ／ＧａＡｌＡｓ发光管测量，光学增益达１４７０。     

InGaAs/InP材料的Zn扩散技术

使用MOCVD反应室进行了InGaAs和InP材料上的Zn扩散工艺条件研究.通过控制扩散温度、扩散源浓度和扩散时间三个主要工艺参数,研究了InGaAs/InP材料的扩散系数和扩散规律,获得了优化的扩散条件.试验表明,该扩散工艺符合原子扩散规律,扩散现象可以用填隙-替位模型解释.样品经过快速退火过程,获得了极高的空穴浓度.InP的空穴浓度达到7.7×1018/cm3,而InGaAs材料达到7×1019/cm3.在优化的扩散条件下,Zn扩散的深度和浓度精确可控,材料的均匀性好,工艺重复性好,能够应用于光电探测器或其他器件.     

Measurement of Deep Energy Level in InP：Fe by the Method of OTCS

We have measured the deep energy level of the InP:Fe which is semi -insulator through the method of OTCS.The effect of light intensity on OTCS measurement is mainly discussed. There are electron trap of ET=0.034 eV and hole trap of ET=1.13 eVin InP:Fe under the strong light and low temperature .The location of the OTCS peak of electron trap(ET=0.34 eV)moves towards the direction of high temperaturer,when the light intensity was increased,ET is different under different light intensity .It is corrected in terms of theory that the stuff ratio of the deep energy level is affected by the light intensity. The experiments show that the error is decreased greatly with the correction.     

无杂质空穴扩散法研制可调InGaAs/InP激光器

用无杂质空穴扩散（ Ｉ Ｆ Ｖ Ｄ） 法研制了延伸光腔分立电极 Ｉｎ Ｇａ Ａｓ／ Ｉｎ Ｐ 半导体激光器。激光器材料的光发光谱说明由 Ｉ Ｆ Ｖ Ｄ 法可以造成量子阱材料带隙蓝移（３０ ～４０）ｎ ｍ 。材料带隙蓝移量与 Ｉ Ｆ Ｖ Ｄ 处理中的退火温度和退火时间有关,表面 Ｓｉ Ｏ２ 厚度亦有一定影响。延伸光腔波导损失较低,由此方法制作的分立电极激光器的阈值电流随延伸光腔部分所加的调制电流而变化,变化的阈值电流可从４０ ｍ Ａ 降至３０ ｍ Ａ。     

带有复合掺杂层集电区的InP/InGaAs/InP DHBT直流特性分析

设计了一种新结构InP/InGaAs/InP双异质结双极晶体管(DHBT),在集电区与基区之间插入n+-InP层,以降低集电结的导带势垒尖峰,克服电流阻挡效应.采用基于热场发射和连续性方程的发射透射模型,计算了n+-InP插入层掺杂浓度和厚度对InP/InGaAs/InP DHBT集电结导带有效势垒高度和I-V特性的影响.结果表明,当n+-InP插入层掺杂浓度为3×1019cm-3、厚度为3nm时,可以获得较好的器件特性.采用气态源分子束外延(GSMBE)技术成功地生长出InP/InGaAs/InP DHBT结构材料.器件研制结果表明,所设计的DHBT材料结构能有效降低集电结的导带势垒尖峰,显著改善器件的输出特性.