Cu/SiO2逐层沉积增强无杂质空位诱导InGaAsP/InGaAsP量子阱混杂

研究了Cu/SiO_2逐层沉积增强的无杂质空位诱导InGaAsP/InGaAsP多量子阱混杂(QWI)行为。在多量子阱(MQW)外延片表面,采用等离子体增强的化学气相沉积(PECVD)不同厚度的SiO_2,然后溅射5 nm Cu,在不同温度下进行快速热退火(RTA)诱发量子阱混杂。通过光荧光(PL)谱表征样品在QWI前后的变化。实验结果表明,当RTA温度小于700℃时,PL谱峰值波长只有微移,且变化与其他参数关系不大;当RTA温度大于700℃时,PL谱峰值波长移动与介质层厚度和RTA时间都密切相关,当SiO_2厚度为200 nm,退火温度为750℃,时间为200 s时,可获得54.3 nm的最大波长蓝移。该种QWI方法能够诱导InGaAsP MQW带隙移动,QWI效果与InGaAsP MQW中原子互扩散激活能、互扩散原子密度以及在RTA过程中热应力有关。     

Cu溅射诱导增强量子阱混杂实验研究

在InP基异质结InGaAsP多量子阱(MQW)结构上溅射Cu/SiO2复合层,开展了量子阱混杂(QWI)材料的实验研究。经快速退火(RTA),实现了比常规无杂质空位扩散(IFVD)方法更大的带隙波长蓝移量。在750℃、200s的退火条件下,获得最大172nm的波长蓝移;通过改变退火条件,可实现不同程度的蓝移,满足光子集成技术中不同器件对带隙波长的需求。为了验证其用于光子集成领域的可行性,利用混杂技术分别制备了宽条激光器和单片集成电吸收调制激光器(EML)。在675℃退火温度,80s、120s和200s的退火时间下分别实现了61、81和98nm的波长蓝移;并且,相应的宽条激光器的电激射光(EL)谱偏调量与其材料的光致荧光(PL)谱偏调量基本一致。在675℃、120s退火条件下,制备的EML集成器件中,电吸收调制器(EAM)和分布反馈(DFB)激光器区的蓝移量分别83nm和23.7nm,相对带隙差为59.3nm。EML集成器件在激光器注入电流为100mA、调制器零偏压时出光功率达到9.6mW;EAM施加-5V反向偏压时静态消光比达16.4dB。     

基于循环退火技术的InGaAs/AlGaAs量子阱混杂

为了解决由于激光器腔面处的光吸收引起的腔面光学灾变损伤(COD),采用无杂质空位扩散(IFVD)法,研究了由SiO2电介质层诱导的InGaAs/AlGaAs量子阱结构的带隙蓝移。使用等离子化学气相沉积(PECVD)在InGaAs/AlGaAs量子阱的表面生长SiO2电介质层;然后采用IFVD在N2环境下进行高温退火实验,从而实现量子阱混杂(QWI)。实验结果表明:蓝移量的大小随退火时间和电介质层厚度的变化而变化,样品覆盖的电介质层越厚,在相同的退火温度下承受的退火时间越长,得到的蓝移量也越大。然而,在高温退火中的时间相对较长时,退火对量子阱造成的损坏相当大。高温短时循环退火,能够在保护量子阱晶体质量的同时实现QWI。通过在850℃退火6min下循环退火5次,得到了46nm的PL蓝移,且PL峰值保持在原样品的80%以上。     

氢离子注入法提高InAsP/InP应变多量子阱发光特性

采用气态源分子束外延系统生长了InAsP/InP应变多量子阱,研究了H 注入对量子阱光致发光谱的影响以及高温快速退火对离子注入后的量子阱发光谱的影响.发现采用较低H 注入能量(剂量)时,量子阱发光强度得到增强;随着H 注入能量(剂量)的增大,量子阱发光强度随之减小.H 注入过程中,部分隧穿H 会湮灭掉量子阱结构界面缺陷,同时H 也会对量子阱结构带来损伤,两者的竞争影响量子阱发光强度的变化.高温快速退火处理后,离子注入后的量子阱样品发光峰位在低温10K相对于未注入样品发生蓝移,蓝移量随着H 注入能量或剂量的增大而增加.退火过程中缺陷扩散以及缺陷扩散导致的阱层和垒层之间不同元素互混是量子阱发光峰位蓝移的原因.     

基于空间控制的ICP量子阱混杂技术

本文提出了一种针对InP/InGaAsP材料,基于空间控制技术的ICP量子阱混杂方法。同一片晶片上带隙能量的偏移程度可以通过掩膜上图形的不同占空比灵活的控制。通过一组优化的参数包括ICP-RIE刻蚀深度,二氧化硅沉积厚度,退火过程等,一个样品上,同时实现了五个不同的蓝移,其中最大的蓝移量达到75nm。结果显示在单片集成器件特别是多带隙结构器件的制作中这是一种有效的方法。     

等离子诱导QWI对InP/InGaAsP结构的影响

为了比较简单地在同一外延片上得到具有不同带隙结构的有源器件与无源器件的PIC(光子集成电路)和OEIC(光电子集成电路),采用等离子诱导QWI(量子阱混杂)与RTA(快速热退火)技术获得了InP/InGaAsP结构材料的带隙蓝移,其中通过在材料表面沉积不同占空比的SiO2灰度掩膜来灵活控制带隙偏移量。实验中这种方法在基片上获得了5种带隙波长,其中最大波长偏移为75nm,实验结果说明这种技术是实现PIC和OEIC的有效手段,特别是在多带隙结构中具有广阔的应用前景。     

采用IFVD-QWI技术制备电吸收调制DFB激光器

采用等离子体增强化学气相沉积 (PECVD) 法在I nGaAsP多量子阱/InP缓冲层/InGaAs层上沉积SiO₂薄膜,通过N₂气氛下快速热退火(RTA )方法实现无杂质空位扩散(IFVD)的量子阱混杂(QWI)。对不同退火温度下量子 阱增益峰值波长的蓝移特性进行了实验摸索,在780℃@80s的退火条 件下,可以获得最大72.8nm的相对波长 蓝移量,并且发现快速热退火RTA温度低于780℃以下时,LD区的波长 蓝移量随温 度变化基本能控制在10nm以内。 通过选取合适退火条件实现了光荧光(PL)峰值波长约50nm的蓝移量, 在选区制备出合适带隙波长材料的基 础上,在LD区制作全息光栅并二次外延P型掺杂电接触层后,采用标准化浅脊波导电吸收 调制(EAM)分布反馈 激光器(EML)工艺制备了1.5μm波长的EML管芯,器件阈值为 20m A,出光功率达到2mW@90mA,静态消光比在＋6V反偏压下为9.5dB。     

二氧化硅覆盖退火增强磷化铟基体激光器材料的量子阱混合

我们对SiO2覆盖退火增强InGaAs/InGaAsP/InP激光器材料量子阱混合技术进行了实验研究.相对于原始样品,退火时无SiO2覆盖的样品经800℃,30s快速退火后,其光致发光谱的峰值波长“蓝移”了7nm,退火时有SiO2覆盖的样品经过同样的快速退火后,其光致发光谱的峰值波长“蓝移”了56nm.即在同一片子上实现了在需要量子阱混合的区域带隙的“蓝移”足够大的同时,不希望量子阱混合的区域能带结构的变化创记录的小.本文认为增大量子阱的宽度、采用无应力的量子阱结构以及引入足够厚的缓冲层可以改善量子阱材料的晶格质量,有利于提高量子阱混合技术的可靠性与重复性,     

磷离子注入诱导InGaAsP／InP双量子阱混合的研究

本文用光荧光(PL)方法研究了磷离子注入具有两个不同发射波长的InGaAsP/InP双量子阱结构引起的混合。注入能量为120keV,剂量范围为1×1011-1×1014/cm2。注入后,在高纯氮保护下,样品在700℃进行快速热退火30秒。实验结果表明,小剂量注入(～1011/cm2)能较好地诱导近表面阱的混合,且两个阱保持了不同发射波长,说明离子注入诱导量子阱混合与注入深度有关。大剂量注入(>1012/cm2)时,发射波长为1.59μm量子阱混合的程度(蓝移值大于130nm)超过了1.52μm量子阱混合的程度,且两个阱的PL发射峰基本上合并成一个单峰。     

含磷组分薄膜对InGaAsP/InP多量子阱无序处理的影响

报道了采用不同的电介质薄膜SiO2、SiOxNy、Si3N4和SiOxPyNz及其组合用于InGaAsP/InP多量子阱材料的包封源.在高纯氮气保护下经850℃、7s的快速退火处理,结果发现:含磷组分SiOxPyNz电介质薄膜包封下的InGaAsP/InP量子阱带隙展宽十分显著,高达224meV,PL谱峰值波长蓝移342nm,半宽较窄仅为25nm,说明量子阱性能保持十分良好,并对此现象的成因做了初步分析.     

InGaAsP/InP Double Quantum Well Intermixing Induced by Phosphorus Ion Implantation

A quantum well intermixing(QWI) investigation on double quantum well(DQW) structure with two different emitting wavelength caused by phosphorus ion implantation and following rapid thermal annealing (RTA) was carried out by means of photoluminescence(PL). The ion implantation was performed at the energy of 120 kev with the dose ranging from 1 × 1011 cm-2 to 1× 1014 cm-2. The RTA was performed at the temperature of 700 ℃ for 30 s under pure nitrogen protection. The PL measurement implied that the band gap blue-shift from the upper well increases with the ion dose faster than that from lower well and the PL peaks from both QWs remained well separated under the lower dose implantation(～1×1011 cm-2 ) indicating that the implant vacancy distribution affects the QWI. When the ion dose is over ～ 1 × 1012 cm-2 , the band gap blue-shift from both wells increases with the ion dose and finally the two peaks merge together as one peak indicating the ion implantation caused a total intermixing of both quantum wells.     

Multi-bandgap photonic materials and devices fabricated by UV-laser induced quantum well intermixing

Ultraviolet(UV)-laser induced quantum well intermixing(QWI) technique can generate large multiple bandgap blue shifts in III-V quantum well semiconductor heterostructure.The application of the UV-laser QWI technique to fabricate multi-bandgap photonic devices based on compressively strained InGaAsP/InP quantum well laser microstructure is reported.We show that under certain UV-laser irradiation conditions,the photoluminescence(PL) intensity can be enhanced,and the full width at half maximum(FWHM) linewidth can be reduced.The blue shift of bandgap can reach as large as 145 nm,while the PL intensity is about 51% higher than that of the as-grown material.Experimental results of post growth wafer level processing for the fabrication of bandgap-shifted waveguides and laser diodes are presented.     

光子吸收诱导无序技术的光荧光谱研究

运用 1 0 6 4μm连续输出的Nd∶YAG激光器 ,对与InP晶格匹配的InGaAsP四元系量子阱材料进行了光子吸收诱导无序 (PAID)技术的研究。通过光荧光谱 (PL)的测量 ,证明有量子阱混合现象产生。衬底预加热和聚焦激光束结果表明 ,PAID中辐照时间与衬底温度、辐照的平均功率密度密切相关。聚焦激光照射后的荧光双峰表明PAID有一定的定域处理能力。     

Effects of defect,carrier concentration and annealing process on the photoluminescence of silicon pn diodes

Silicon pn diodes were fabricated by ion implantation of B and P ions with different doses and subsequent annealing processes. Room temperature photoluminescence (PL) were investigated and the factors affecting the PL intensity were analyzed. Results show that both kinds of pn diodes have PL peak centered at about 1140 nm. Dislocation loops resulted from ion implantation and annealing process may enhance the light emission of silicon pn diode due to its band quantum confinement effect to carriers. The luminescence intensity depends on the carrier concentrations in the implantation region. It should be controlled at the range of 1–6×10¹⁶ cm⁻³. Moreover, the PL intensities of pn diodes with furnace annealing (FA) are higher than those with rapid thermal annealing, and the annealing temperature range for FA is 900–1100 °C.     

The effects of InP grown by He-plasma assisted epitaxy onquantum-well intermixing

He-plasma assisted InP (He*-InP) layers grown by gas source molecular beam epitaxy (GSMBE) have been employed to enhance quantum well (QW) intermixing induced by rapid thermal annealing in a 1.5 μm InGaAsP QW laser structure. Inserting a 40 nm He*-InP layer just above the active region enhances the blue-shift for anneal temperatures larger than 680°C, and a 42 nm additional blue-shift is obtained at 750°C for samples with the He*InP layer, compared to samples with normal InP replacing the He*-InP. This is accompanied by a reduction in the photoluminescence (PL) intensity for anneal temperatures greater than 600°C and is attributed to the migration of nonradiative defects from the He*-InP layer into the QWs. Insertion of a thin InGaAs layer between the He*-InP layer and the QW blocks the diffusion of these nonradiative defects into the QW. The results indicate that the He*-InP material could prove useful in QW intermixing to achieve integrated optoelectronic devices, in particular for high-frequency devices which require short carrier lifetimes     

InGaAsP量子阱混合技术理论及模拟研究

本文以品格中原子的扩散理论为基础，分析了四元系InGaAsP半导体材料中Ⅲ、Ⅴ族原子的扩散规律，建立了量子阱和超晶格结构中量子阱混合(QWI)的理论模型，模拟计算了半导体材料中组分浓度与扩散长度的关系，以及应变与扩散长度的关系，计算分析了应变对量子阱带隙、带结构和量子跃迁的影响，获得了一些有价值的结论，为量子阱混合试验和量子阱及超晶格集成器件的开发和研究提供了重要的理论基础。     

GaAs／AlGaAs非对称耦合双量子阱界面混合效应荧光谱研究

用分子束外延系统生长了GaAs/AlGaAs非对称耦合双量子阱（ACDQW）,用组合注入的方法,在同一块衬底上获得了不同注入离子和不同注入剂量的耦合量子阱单元,没有经过快速热退火过程,在常温下测量了不同单元的显微光荧光谱,发现了带间跃迁能量最大变化范围接近100meV,组合注入所导致的能量移动要大于单独注入导致的能量移动。     

High-temperature operation of 1.26 μm Fabry-Perot laser with InGaAs metamorphic buffer on GaAs substrate

Optoelectronic devices with a wide temperature operating range are required for metropolitan and access networks. The temperature sensitivity of the threshold current depends on the conduction band offset of the active layer. The design of optoelectronic devices is strictly limited by the lattice constant of the substrates. Conventional InP-based lasers with InGaAsP multiple quantum wells (MQWs) are sensitive to the ambient temperature and require additional temperature control devices. This is due to the small conduction band offset of the active layer.