具有超晶格雪崩区的电子倍增型雪崩光电二极管

基于碰撞离化理论研究设计了In0.53 Ga0.47 As/In0.52 Al0.48As电子倍增超晶格结构雪崩光电二极管,使用MOCVD外延得到实验片,经过工艺流片后进行封装测试.测试结果显示,具有超晶格雪崩区的电子倍增型APD器件,其暗电流可以控制在纳安级,光电流增益达到140,证明具有超晶格雪崩区的电子倍增型雪崩光电二极管具有很好的光电探测性能.     

In0.53Ga0.47As/In0.52Al0.48As雪崩光电二极管的数值模拟研究

建立了SACM型In0.53Ga0.47As/In0.52Al0.48As雪崩光电二极管(APD)的分析模型,通过数值研究和理论分析设计出高性能的In0.53Ga0.47As/In0.52Al0.48As APD。器件设计中,一方面添加了In0.52Al0.48As势垒层来阻挡接触层的少数载流子的扩散,进而减小暗电流的产生;另一方面,雪崩倍增区采用双层掺杂结构设计,优化了器件倍增区的电场梯度分布。最后,利用ATLAS软件较系统地研究并分析了雪崩倍增层、电荷层以及吸收层的掺杂水平和厚度对器件电场分布、击穿电压、IV特性和直流增益的影响。优化后APD的单位增益可以达到0.9 A/W,在工作电压(0.9 Vb)下增益为23.4,工作暗电流也仅是纳安级别(@0.9 Vb)。由于In0.52Al0.48As材料的电子与空穴的碰撞离化率比InP材料的差异更大,因此器件的噪声因子也较低。     

极化调控AlGaN基日盲紫外雪崩光电二极管性能优化

通过数值模拟研究了各层参数对极化调控的背入射异质结分离吸收倍增层型AlGaN基雪崩光电二极管(APDs)性能的影响,并详细分析相关物理机制。计算结果表明:参数的优化有利于降低APDs的雪崩击穿电压,提高倍增因子。特别是对于P-GaN层AlGaN雪崩光电二极管,倍增因子增加可超过300%,这是由于该雪崩光电二极管的GaN/Al0.4Ga0.6N异质界面的强极化电荷调节了倍增层、中间插入层、吸收层的电场分布,增加了载流子的注入和倍增效率,同时还由于参数优化减小了倍增时的暗电流。     

波导雪崩光电二极管有望用于1550 nm光

美国德克萨斯大学和朗讯科技公司的研究人员用端照射波导结构制作了波导约束 In Ga As/ In Al As雪崩光电二极管 (APD)。该器件综合了波导与雪崩光电二极管的特征 ,可望用作对 1.55μm通信波段快速灵敏的光电二极管。该器件建立在独立吸收负载倍增 (SACM)电路的基础上 ,全增益带宽 2 7GHz,增益 -带宽乘积 12 0 GHz。因为 In Al As可透过 1.55μm光 ,且过量噪声低 ,所以选它作器件的倍增区和包覆材料。在 In P衬底和缓冲层上用分子束外延生长各层。完全的波导独立吸收负载倍增雪崩光电二极管在 90 %击穿时暗电流保持在 50 n A以下 …     

优质Al_xGa_(1-x)As/GaAs(x≤0.6)SAM—APD超晶格结构的MBE生长

本文描述了采用Varian GenⅡMBE系统,和VA-175型砷裂解炉,以及5个“9”的铍作p型掺杂剂,严格仔细地控制外延生长过程,成功地制备了优质的Al_xGa_(1-x)As/GaAs(x≤0.6)SAM-APD超晶格结构外延材料。倍增层p-Al_(0.6)Ga_(0.4)As的载流子浓度低达2.3×10~(14)cm~(-3)电子与空穴离化率的比值为25.0。此材料用于制作超晶格雪崩光电探测器,器件性能有显著的提高。在初始光电流I_(po)=100nA下,反向偏压为80伏得到的内部雪崩增益为1900,计算分析最大雪崩倍增因子高达6050。     

10Gb／s光通信系统用高速超晶格雪崩二极管

介绍了载流子倍增层采用超晶格雪崩光电二极管（ＡＰＤ）的原理，分析了影响ＡＰＤ特性的离化机理。说明了利用超晶格异质界面大的导带不连续性是增大离化率比从而改善噪声、响应速度等特性的有效途径。最后介绍了超晶格ＡＰＤ的最新进展。     

具有抑制边缘击穿的层叠结结构的平面型InGaAs/InP盖革雪崩光电二极管的设计

通过有限元分析设计了具有抑制边缘击穿的层叠边缘结结构的平面型InGaAs/InP盖革雪崩光电二极管. 通过仔细地控制中央区域结的深度,光电二极管的击穿电压降至54.3V; 同时通过调整InP倍增层的掺杂浓度和厚度,沿器件中轴的电场分布也得到了控制. 在有源区的边缘采用层叠pn结结构有效地抑制了过早边缘击穿现象. 仿真模拟显示四层层叠结构是边缘击穿抑制效果和制造工艺复杂度的一个好的折衷方案,该结构中峰值电场强度为5.2E5kV/cm,空穴离化积分最大值为1.201. 本文提供了一种设计高性能的InGaAs/InP光子计数雪崩光电二极管的有效方法.     

10Gb／s光通信系统用高速超晶格雪崩二极管

介绍了载流子倍增层采用超晶格雪崩光电二极管（ＡＰＤ）的原理，分析了影响ＡＰＤ特性的离化机理。说明了利用超晶格异质界面大的导带不连续性是增大离化率比从而改善噪声、响应速度等特性的有效途径。最后介绍了超晶格ＡＰＤ的最新进展。     

具有抑制边缘击穿的层叠结结构的平面型InGaAs/InP盖革雪崩光电二极管的设计

通过有限元分析设计了具有抑制边缘击穿的层叠边缘结结构的平面型InGaAs/InP盖革雪崩光电二极管.通过仔细地控制中央区域结的深度,光电二极管的击穿电压降至54.3V;同时通过调整InP倍增层的掺杂浓度和厚度,沿器件中轴的电场分布也得到了控制.在有源区的边缘采用层叠pn结结构有效地抑制了过早边缘击穿现象.仿真模拟显示四层层叠结构是边缘击穿抑制效果和制造工艺复杂度的一个好的折衷方案,该结构中峰值电场强度为5.2×105kV/cm,空穴离化积分最大值为1.201.本文提供了一种设计高性能的InGaAs/InP光子汁数雪崩光电二极管的有效方法.     

SiGe/Si单光子雪崩光电二极管仿真

通过理论模拟CMOS工艺兼容的SiGe/Si 单光子雪崩二极管,研究并讨论了掺杂条件对于电场分布、频宽特性、以及器件量子效率的影响。设计出具有浅结结构、可在盖革模式下工作、低击穿电压(30 V)的1.06 m单光子技术雪崩光电二极管。器件采用分离吸收倍增区结构,其中Si材料作为倍增区、SiGe材料作为吸收区,这充分利用了硅材料较高的载流子离化比差异,降低了器件噪声;在1.06 m波长下,SiGe探测器的量子效率为4.2%,相比于Si探测器的效率提高了4 倍。仿真表明优化掺杂条件可以优化电场分布,从而在APD击穿电压处获得更好的带宽特性。     

An InGaAs/InAlAs superlattice avalanche photodiode with a gain bandwidth product of 90 GHz

The authors describe the fabrication of an InGaAs/InAlAs superlattice avalanche photodiode with a gain-bandwidth product of 90 GHz. The device is composed of an InGaAs/InAlAs superlattice multiplication region and an InGaAs photoabsorption layer. The effect of the superlattice multiplication region thickness on the gain-bandwidth product was studied. A gain-bandwidth product of 90 GHz was obtained for the device with a multiplication region thickness of 0.52 mu m. Low noise performance is compatible with the high gain-bandwidth product due to improvement of the ionization rate ratio made by introducing a superlattice structure into the multiplication region.<>     

SAGCM-APD增益影响因子分析与优化

应用二维漂移扩散模型研究具有分立吸收层、渐变层、电荷层和倍增层结构(SAGCM)的InGaAsP-InP雪崩光电探测器(APD),仿真分析了不同电荷层、倍增层厚度和掺杂浓度对电场分布、电流响应及击穿电压的影响,特别是参数变量对增益计算模型的影响,载流子传输过程的时间依赖关系和倍增层中所处位置的影响,仿真结果表明:较高掺杂浓度和较薄电荷层结构可以改变器件内部的电场分布,进而提高增益值.当入射光波长为1.55μm,光功率为500 W/m2时,光电流响应量级在10-2A;阈值电压降低到10V以下,击穿电压为42.6V时,器件倍增增益值大于100.     

An optimized avalanche photodiode

The feasibility of a fast, high-gain photodetector based on the phenomenon of avalanche multiplication in semiconductors has been investigated. Based on the process of carrier multiplication in a high electric field, criteria for the design of an optimized avalanche photodiode and for the choice of the best semiconductor material are developed. The device theory of an optimized, realizable avalanche photodiode is presented. A practical silicon device optimized for the detection of light with a wavelength of 9000Å is suggested and design parameters are presented. Details of the fabrication process are given and the performance of experimental devices is compared to the device theory presented. The results of the study indicate that it is possible to achieve a silicon photomultiplier with a quantum efficiency-bandwidth product of the order of 100 GHz for the detection of light up to a wavelength of over 9000Å.     

InGaAs/InAlAs雪崩光电二极管仿真设计

设计了一种InGaAs/InALAs雪崩光电二极管(APD),并利用MEDICI软件进行了模拟仿真.器件采用背入射探测方式.雪崩增益区采用埋层设汁,省略了保护环等结构;并使用双层掺杂,有效降低了增益区电场的梯度变化.由于结构简单,因此仪需要利用分子束外延(MBE)生长精确控制每层结构即可.由于InAlAs材料的空穴与电子的离化率有较大的筹异,因此器件具有较低的噪声因子.     

Theory of the doped quantum well superlattice APD: A new solid-state photomultiplier

A new superlattice avalanche photodiode structure consisting of repeated unit cells formed from a p-i-n Al0.45Ga0.55As region immediately followed by near intrinsic GaAs and Al0.45Ga0.55As layers is examined using an ensemble Monte Carlo calculation. The effects of various device parameters, such as the high-field layer width, GaAs well width, low-field AlGaAs layer width, and applied electric field on the electron and hole ionization coefficients is analyzed. In addition, the fraction of electrons which ionize in a spatially deterministic way, at the same place in each stage of the device, is determined. As is well known, completely noiseless amplification can be achieved if each electron ionizes in each stage of the device at precisely the same location while no holes ionize anywhere within the device. A comparison is made between the doped quantum well device and other existing superlattice APD's such as the quantum well and staircase APD's. It is seen that the doped quantum well device most nearly approximates photomultiplier-like behavior when applied to the GaAs/AlGaAs material system amongst the three devices. In addition, it is determined that none of the devices, when made from GaAs and AlGaAs, fully mimic ideal photomultiplier-like performance. As the fraction of electron ionizations per stage of the device is increased, through variations in the device geometry and applied electric field, the hole ionization rate invariably increases. It is expected that ideal performance can be more closely achieved in a material system in which the conduction band edge discontinuity is a greater fraction of the band gap energy in the narrow-band gap semiconductor.     

10Gbit/s InGaAs/InP雪崩光电二极管

基于InGaAs/InP吸收区、渐变区、电荷区和倍增区分离雪崩光电二极管(SAGCMAPD)器件结构,利用数值计算方法,模拟了各层参数对器件频率响应特性的影响.模拟结果表明,吸收层、倍增层厚度及电荷层面电荷密度可影响器件的-3 dB带宽;随增益的增加,器件带宽会逐渐降低;电荷层面电荷密度对器件击穿电压有明显影响.结合此模拟结果,制作出了高速InGaAs/InP雪崩光电二极管,并对器件进行了封装测试.测试结果表明,该结果与模拟结果相吻合.器件击穿电压为30 V;在倍增因子为1时,器件响应度大于0.8 A/W;在倍增因子为9时,器件暗电流小于10 nA,-3 dB带宽大于10 GHz,其性能满足10 Gbit/s光纤通信应用要求.     

A wide-bandwidth low-noise InGaAsP-InAlAs superlattice avalanchephotodiode with a flip-chip structure for wavelengths of 1.3 and 1.55μm

The authors reports the fabrication of a flip-chip InGaAsP-InAlAs superlattice avalanche photodiode using gas source molecular beam epitaxy. The incident light reaches the InGaAs photoabsorption layer through the InP substrate and an InGaAsP-InAlAs superlattice multiplication region which are transparent for wavelengths of 1.55 and 1.3 μm. The light reflection by the electrode enables the absorption layer to be as thin as 0.8 μm without significantly reducing the quantum efficiency. A maximum bandwidth of 17 GHz was obtained at a low multiplication factor because the transit time through the absorption layer is reduced     

Amorphous silicon/silicon carbide superlattice avalanchephotodiodes

An a-Si/SiC:H superlattice avalanche photodiode (SAPD) has been successfully fabricated on an ITO/glass substrate by plasma-enhanced chemical vapor deposition. The room-temperature electron and hole impact ionization rates, α and β, have been determined for the a-Si/SiC:H superlattice structure by photocurrent multiplication measurements. The ratio α/β is 6.5 at a maximum electric field of 2.08×10⁵ V/cm. Avalanche multiplications in the superlattice layer yields an optical gain of 184 at a reverse bias V_R=20 V and an incident light power P_in=5 μW. An LED-SAPD photocouple exhibited a switching time of 4.5 μs at a load resistance R-1.8 kΩ