闭管扩散Zn对InP表面性质的影响

利用闭管扩散方法以Zn3P2为扩散源,在不同扩散温度和扩散时间下对非故意掺杂InP(100)晶片进行扩散.用电化学C-V法(ECV)和二次离子质谱法(SIMS)分别测出了空穴浓度和Zn的浓度随深度的分布曲线.结果表明扩散后InP表面空穴和Zn的浓度在扩散结附近突然下降,InP表面空穴浓度主要取决于扩散温度,扩散深度随着扩散时间的增长而变大,InP表面Zn浓度一般比空穴浓度高一个数量级.另外对扩散后的样品进行光致发光(PL)测试,表明在保证表面载流子浓度的同时,适当降低扩散温度和增加扩散时间能减小对InP表面性质的影响.     

闭管扩散Zn对InP表面性质的影响

利用闭管扩散方法以Zn3P2为扩散源,在不同扩散温度和扩散时间下对非故意掺杂InP(100)晶片进行扩散.用电化学C-V法(ECV)和二次离子质谱法(SIMS)分别测出了空穴浓度和Zn的浓度随深度的分布曲线.结果表明扩散后InP表面空穴和Zn的浓度在扩散结附近突然下降,InP表面空穴浓度主要取决于扩散温度,扩散深度随着扩散时间的增长而变大,InP表面Zn浓度一般比空穴浓度高一个数量级.另外对扩散后的样品进行光致发光(PL)测试,表明在保证表面载流子浓度的同时,适当降低扩散温度和增加扩散时间能减小对InP表面性质的影响.     

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.     

杂质Zn在InP中的扩散机制

介绍了杂质Zn在InP中的两种扩散机制,间隙-替代机制和Kick-out机制.InP为n型时,扩散机制为间隙-替代式;InP为p型时,扩散机制为Kick-out式.重点介绍了三种不同模型,解释Zn在InP中通过间隙-替代机制进行扩散时,空穴浓度与Zn浓度不同的原因,并评价了三种模型.     

InP基光电探测器材料的MOCVD锌扩散

锌(Zn)扩散是制作InP基光电探测器(PD)的重要工艺过程.分析了锌扩散的机制,利用金属有机化学气相沉积(MOCVD)设备对InP基PD及雪崩光电探测器(APD)材料进行了锌扩散,由于MOCVD设备具有精确的温度控制系统,所以该扩散工艺具有简单、均匀性好、重复性好的优点.对于扩散后的样品,采用电化学C-V方法和扫描电子显微镜(SEM)等测试分析手段,研究了退火、扩散温度、扩散源体积流量和反应室压力等主要工艺参数对InP材料扩散速率和载流子浓度的影响,并将该锌扩散工艺应用于InP基光电探测器和雪崩光电探测器的器件制作中,得到了优异的器件性能结果.     

Cd和Zn在InP中扩散的研究

本文介绍了在450—700℃的广阔温度范围内研究Cd和Zn向InP扩散的结果,并对结果作了比较。详细研究了Cd,Zn及其化合物等不同杂质源对扩散的影响。我们用结深(x_j)的平方和时间(t)的比值(x_j~2/t)作为扩散速度的度量,并画出了x_j~2/t-1/T(温度)曲线。发现Cd源,特别是CdP_2源的扩散速度较慢,容易控制它扩散的结深和浓度,昕以它是比较理想的扩散杂质源。利用Tien的中性复合体理论,解释了Cd和Zn在InP中扩散的复杂现象。     

Cd和Zn在InP和InGaAsP中的扩散(E_g=0.95～1.35eV)

研究了566～715℃温度范围内 InP 中 Cd 和 Zn 的扩散问题。采用由 Cd_3P_2和 InP 粉末为混合源的 Cd 扩散,使我们能得到几微米以下的浅扩散深度(X_j),并形成无表面损伤的平坦的 p-n 结。另一方面采用包括 Zn_3P_2(或ZnP_2)+InP 粉末为混合源的 Zn 扩散为快速扩散,结果造成扩散前沿不平整。当采用磷硅玻璃(PSG)掩膜进行 InP 的选择扩散时,如果扩散时石英管中的 InP 粉末量不足(≤100mg),发现沿掩膜边缘会产生滑移位错。还进行了与 InP 晶格匹配的 InGaAsP(E_g=0.95～1.35eV)中的 Cd 扩散研究工作。业已发现扩散深度随着带隙能量的减小而单调减小。     

低温下Zn在InGaAsP/InP中的扩散

本文叙述了在n型InP和InGaAsP进行低温平面扩散的实验方法,对低温下Zn在InP和InGaAsP中的扩散机理及其扩散分布图进行了讨论。实验结果表明,Zn在InGaAsP中的扩散速率比Zn在InP中的扩散速率要慢,而载流子浓度却要此InP高。其载流子浓度分布极好地服从余误差函数分布,应用于器件的研制产生了很好的效果。     

InP中低温Zn扩散的研究

一、引言随着长波长光纤通信的迅速发展,InGaAsP/InP双异质结发光器件和探测器件已被人们所重视。Zn向InP中的扩散技术,对InGaAsP/InP光源和探测器件的制备是有重要影响的工艺。近年来已有许多研究。为了制备InGaAsP/InP双异质结发光管的需要,我们研究了InP中Zn的低温扩散技术。本文报导的低温双温区扩散工艺,可得到表面光亮,Zn浓度分布均匀,重复性好,无损伤的高浓度表面层。讨论了Zn在InP中扩散时的行为,解释了扩散过程中的异常现象。     

Nd:YAG连续激光诱导下InP的Zn掺杂

Nd:YAG连续激光辐照在表面蒸有Zn薄膜的n-InP片上,用激光诱导的方法实现Zn在InP中掺杂。形成PN结。用电化学C-V方法和扫描电子显微镜对辐照后的样品进行分析研究,给出激光辐照功率、辐照时间等工艺参数对结深、浓度分布影响.在n-InP片表面得到受主浓度分布均匀、高掺杂（～1019cm-3）、浅结（～1μm）的P-InP。初步分析其掺杂机理是激光诱导下所形成的合金结过程。     

Impurity-induced disordering of AIGalnAs quantum wells by low temperature Zn diffusion

We investigated impurity-induced disordering (IID) in AIGalnAs multi-quantum wells (MQWs) on InP substrate by Zn diffusion under low temperature conditions. Blue-shift of band-gap energy of lattice-matched AIGalnAs MQW on InP strongly depended on the temperature of Zn diffusion. The lattice-matched MQW was not completely disordered below 500°C. On the other hand, photoluminescence spectra from compressively strained AIGalnAs MQW, after disordering was independent of the temperature of Zn diffusion. Considerable disordering was observed in the strained MQW, which was saturated even at the low temperature of 400°C. The measured hole concentration of the Zn diffused layer at 400°C was as low as 3 × l0¹⁸cm⁻³ The IID lasers were also fabricated and characterized. No significant increase in the optical loss due to the Zn diffusion was observed in these lasers. On leave from Toshiba Co., Japan.     

Out-diffusion and reactivation of Zn in InP substrates

The influence of temperature on p-doping in Zn-diffused InP substrates has been investigated. By cooling the diffused InP samples very slowly after diffusion or subjecting them to heat treatment, significant out-diffusion of Zn has been observed. By heat-treating with rapid cooling, a substantial fraction of the incorporated but electrically inactive Zn atoms can be reactivated, resulting in a drastically increased acceptor concentration.     

Zn doping of InP, InAsP/InP, and InAsP/InGaAs heterostructures through metalorganic vapor phase diffusion (MOVPD)

Zinc incorporation by post-growth metalorganic vapor phase diffusion (MOVPD) is used to achieve high p-doping, which is desirable for the fabrication of photodiodes. Diethylzinc (DEZ) is used as precursor and Zn is diffused into InP and InAs_0.6P epitaxial layers grown by low pressure metalorganic vapor phase epitaxy (MOVPE) on different substrate orientations, enabling the investigation of the dislocation density on the Zn incorporation. Diffusion depths are measured using cleave-and-stain techniques, resistivity measurements, electrochemical profiling, and secondary ion mass spectroscopy. High hole concentrations of, respectively, 1.7 10¹⁹ and 6 10¹⁸ cm⁻³, are obtained for, respectively, InAs_0.60P and InP. The diffusion coefficients are derived and the Zn diffusion is used for the fabrication of lattice-mismatched planar PIN InAsP/InGaAs photodiodes.     

Optical properties of Zn-diffused InP layers for the planar-type InGaAs/InP photodetectors

Zn diffusion into InP was carried out ex-situ using a new Zn diffusion technique with zinc phosphorus particles placed around InP materials as zinc source in a semi-closed chamber formed by a modified diffusion furnace.The optical characteristics of the Zn-diffused InP layer for the planar-type InGaAs/InP PIN photodetectors grown by molecular beam epitaxy (MBE) has been investigated by photoluminescence (PL) measurements.The temperature-dependent PL spectrum of Zn-diffused InP samples at different diffusion temperatures showed that band-to-acceptor transition dominates the PL emission,which indicates that Zn was commendably diffused into InP layer as the acceptor.High quality Zn-diffused InP layer with typically smooth surface was obtained at 580 ℃ for 10 min.Furthermore,more interstitial Zn atoms were activated to act as acceptors after a rapid annealing process.Based on the above Zn-diffusion technique,a 50μm planar-type InGaAs/InP PIN photodector device was fabricated and exhibited a low dark current of 7.73 pA under a reverse bias potential of-5 V and a high breakdown voltage of larger than 41 V (I ＜ 10 μA).In addition,a high responsivity of 0.81 A/W at 1.31 μm and 0.97 A/W at 1.55 μm was obtained in the developed PIN photodetector.     

InP/InGaAs(P)材料中的低温开管Zn扩散

为了在InP/InGaAs(P)材料中进行精确的选择扩散,同时又要保证外延生长的多层异质结构不被破坏,提出了一种新的低温开管Zn扩散方法。该法直至在T=500℃,t=5min的条件下,重复性仍很好。应用该法研究了低温条件下Zn在InP,InGaAs(P)材料中的扩散行为。实验首次发现,Zn在InGaAsP材料中的扩散速率与材料中P含量的平方成正比。     

Shallow and selective diffusion of zinc in indium phosphide

Diffusion experiments at 670–720°C from doped silica films into n-type InP are described. The diffusant is Zn. The films are spun on from emulsions and carefully solidified. The diffused samples were investigated mostly by stain etching and additionally by C-V and break-down measurements on Schottky diodes, by four-point-probe and Hall measurements. Homogeneous diffusion fronts were obtained. From the square-root dependence of the diffusion depth on the diffusion time and from the measurements mentioned before an errorfunction-complement type of diffusion profile can be inferred. The evaluation of the results then gives a diffusion coefficient of (2 ± 1) × 10^?10 cm²/s and a total Zn concentration at the surface of about 2 × 10¹⁸ cm^?3. It is demonstrated that with conventional photolithography selective diffusions can be performed.     

Ⅲ-Ⅴ族半导体化合物快速热退火扩Zn方法研究

以GaAs和InP材料为例,对化合物半导体材料中的快速热退火扩Zn可行性进行比较分析,研究表明,化合物半导体材料中快速热退火扩Zn可行性与化合物半导体材料的分解温度有着密切关系。化合物半导体材料分解温度越低,对扩散源、帽层和阻挡层要求越高。针对InP材料高于360℃就分解、低温Zn扩散困难的特点,提出了直接溅射Zn层在410℃低温扩散的方法。对InP快速热退火扩散结果进行分析,初步分析表明其掺杂机理是形成合金结。     

InP/In_xGa_(1-x)As异质结构中Zn元素的扩散机制

采用闭管扩散方式实现了Zn元素在晶格匹配InP/In_(0.53)Ga_(0.47)As及晶格失配InP/In_(0.82)Ga_(0.18)AS两种异质结构材料中的P型掺杂,利用二次离子质谱(SIMS)以及扫描电容显微技术(SCM)对Zn在两种材料中的扩散机制进行了研究.SIMS测试表明:Zn元素在晶格失配材料中的扩散速度远大于在晶格匹配材料中的扩散速度,而SCM测试表明:两种材料中的实际PN结深度与SIMS测得的Zn扩散深度之间存在一定的差值,这是由于扩散进入材料中的Zn元素并没有被完全激活,而晶格失配材料中Zn的激活效率相对更低,使得晶格失配材料中Zn元素扩散深度与PN结深度的差值更大.SCM法是一种新颖快捷的半导体结深测试法,对于半导体器件工艺研究具有重要的指导意义.