InGaAsP/InAlAs superlattice avalanche photodiode

The fabrication of an InGaAsP-InAlAs superlattice avalanche photodiode using a gas source molecular beam epitaxy is discussed. A quaternal alloy of InGaAsP was used for the well layers in order to suppress the dark current due to the tunneling effect. With this structure, the valance band discontinuity almost vanishes and a gain bandwidth of 110 GHz was obtained     

An AlxGa1-xSb avalanche photodiode with again bandwidth product of 90 GHz

An Al_xGa_1-xSb avalanche photodiode (APD) with an Al composition of 0.05 has been fabricated and tested. The measured gain-bandwidth (GB) product of the highly doped diode is 90 GHz. Such a large GB product has never been previously achieved by any APD materials sensitive in the long-wavelength region. This suggests the advantage of the Al_xGa_1-xSb material system for very high-speed operation     

具有优化倍增层InAlAs/InGaAs雪崩光电二极管

通过优化倍增层的厚度,研究了InAlAs/InGaAs雪崩光电二极管增益带宽积和暗电流之间的关系。利用仿真计算得出200 nm厚的倍增层能够改善增益带宽积并降低暗电流。制成的InAlAs/InGaAs 雪崩光电二极管性能优异,与计算趋势一致。在获得0.85 A/W的高响应和155 GHz的增益带宽积的同时,器件暗电流低于19 nA。这项研究对雪崩光电二极管在未来高速传输的应用具有重要意义。     

多级倍增超晶格InGaAs雪崩光电二级管的增益-噪声特性

重点研究了多级倍增超晶格InGaAs雪崩光电二级管(APD)的增益和过剩噪声,建立了新的载流子增益-过剩噪声模型。在常规弛豫空间理论基础上分析了其工作原理,考虑了预加热电场和能带阶跃带来的初始能量效应、电子进入高场倍增区时异质结边界附近的弛豫空间长度修正以及声子散射对碰撞离化系数的影响,提出了用于指导该类APD的增益-过剩噪声计算的修正弛豫空间理论。结果表明:在相同条件下,相比于常规的单层倍增SAGCM结构,多级倍增超晶格InGaAs APD同时具有更高增益和更低噪声,且修正的弛豫空间理论可被推广到更多级倍增的超晶格InGaAs APD结构,在保证低噪声前提下,通过增加倍增级数可提高增益。     

Optimization of charge and multiplication layers of 20-Gbps InGaAs/InAlAs avalanche photodiode

We calculated the correlation between the doping concentration of the charge layer and the multiplication layer for separate absorption, grading, charge, and multiplication InGaAs/InAlAs avalanche photodiodes (APDs). For this purpose, a predictable program was developed according to the concentration and thickness of the charge layer and the multiplication layer. We also optimized the design, fabrication, and characteristics of an APD for 20 Gbps application. The punch-through voltage and breakdown voltage of the fabricated device were 10 V and 33 V, respectively, and it was confirmed that these almost matched the designed values. The 3-dB bandwidth of the APD was 10.4 GHz, and the bit rate was approximately 20.8 Gbps.     

高速InP/InGaAs雪崩光电二极管

采用分层吸收渐变电荷倍增(SAGCM)结构,通过两次扩散、多层介质淀积、AuZn p型欧姆接触、AuGeNi n型欧姆接触等工艺,设计制造了正面入射平面InP/InGaAs雪崩光电二极管,器件利用InGaAs做吸收层,InP做增益层,光敏面直径50 μm;测试结果表明器件有正常的光响应特性,击穿电压32～42 V,在低于击穿电压2 V左右可以得到大约10A/W的光响应度,在0到小于击穿电压1 V的偏压范围内,暗电流只有1 nA左右;器件在2.7 GHz以下有平坦的增益.     

Optical characteristics of a superlattice avalanche photodiode

Avalanche photodiodes using III–V materials are suitable for use in long distance fiber optic communication systems due to their faster speed of response and high gain. The superlattice APD is expected to be far more attractive than the conventional APD for their better noise performance. Theoretical studies have been carried out on the photoresponse characteristics of an Al_xGa_1−xAs/GaAs superlattice p⁺−i−n⁺ structure. It is observed that for a particular d.c. multiplication factor the normalised gain of the device remains constant with frequency and falls steadily after a certain frequency. The band width of the response curve increases with decrease in d.c. multiplication factor. Furthermore, the output current of the superlattice structure increases with the increase in optical power. The device also shows a good percentage of quantum efficiency.     

InGaAs avalanche photodiode with InP p-n junction

A new InGaAs avalanche photodiode structure that has an InGaAs light absorption region and InP avalanche multiplying region is proposed. A dark-current density of 2.2 × 10?3 A/cm2 at 90% of breakdown voltage and a multiplication factor of 45 were obtained for the new structure diode fabricated from a liquid-phase epitaxially grown wafer.     

Planar InP/InGaAs avalanche photodetector with gain-bandwidth product in excess of 100 GHz

A planar separate absorption, grading, charge and multiplication (SAGCM) avalanche photodiode (APD) structure was fabricated, allowing for a thin undoped multiplication layer, without the use of guard rings. A gain-bandwidth (GBW) product in excess of 100 GHz has been measured for the first time.<>     

An SIS mixer for 90–120 GHz with gain and wide bandwidth

An SIS mixer for the 3 mm wavelength band has been developed. It has sufficient RF bandwidth to allow double-sideband operation at an IE of 1.4 GHz. Available gain of around 3 dB has been measured, along with mixer temperatures of 20 to 40K (both double sideband). The junctions were fabricated using a lead-alloy technology (Pb?In?Au/oxide/-Pb?Bi). Coupling and tuning structures were integrated onto a quartz substrate along with the junctions. The measurements were made at physical temperatures around 3.1K, achieved with a closed-cycle refrigerator.     

Multiplication-dependent frequency responses of InP/InGaAs avalanche photodiode

The intrinsic response time of InP/InGaAs APD has been reported. The multiplication factor dependent frequency responses were measured up to multiplication factor of 24. The results show the gain bandwidth of InP/InGaAs APDs is 10 GHz, and the intrinsic response time to be 16 ps.     

New type InGaAs/InP heterostructure avalanche photodiode with buffer layer

A new type heterostructure avalanche photodiode (HAPD) is proposed and successfully fabricated by liquid phase epitaxy and Zn-diffusion. The HAPD has been made from a successively grown wafer which consists of In0.53Ga0.47As light absorption layer, InGaAsP buffer layers and InP avalanche multiplication layer on n-InP substrate. Dark current density of 1 × 10^-4Acm^-2at 0.9 VBis achieved. When illuminating with 1.15 µm light, the diode has a maximum multiplication gain of 880 and an external quantum efficiency of 40%. The quantum efficiency is markedly improved than that of previously reported HAPD.     

High-speed-response InGaAs/InP heterostructure avalanche photodiode with InGaAsP buffer layers

The optical response time of an InGaAs/InP heterostructure avalanche photodiode (HAPD) with InGaAsP buffer layers is reported. It is shown that the buffer layers play an important role in reduction of the pile-up effect and are considered to be effective in achieving high-speed InGaAs/InP HAPDs.     

InGaAs/InAlAs SCH-MQW lasers with superlattice optical confinementlayers grown by MBE

InGaAs/InAlAs separate-confinement-heterostructure multiple-quantum-well (SCH-MQW) lasers with superlattice optical confinement layers grown by molecular beam epitaxy are discussed. Room-temperature operation with a low threshold current density of 1.7 kA/cm² at 1.537 μm wavelength is obtained for these lasers     

Very high gain millimeter-wave InAlAs/InGaAs/GaAs metamorphicHEMT's

We report the first demonstration of W-band metamorphic HEMTs/LNA MMICs using an AlGaAsSb lattice strain relief buffer layer on a GaAs substrate. 0.1×50 μm low-noise devices have shown typical extrinsic transconductance of 850 mS/mm with high maximum drain current of 700 mA/mm and gate-drain breakdown voltage of 4.5 V. Small-signal S-parameter measurements performed on the 0.1-μm devices exhibited an excellent f_T of 225 GHz and maximum stable gain (MSG) of 12.9 dB at 60 GHz and 10.4 dB at 110 GHz. The three-stage W-band LNA MMIC exhibits 4.2 dB noise figure with 18 dB gain at 82 GHz and 4.8 dB noise figure with 14 dB gain at 89 GHz, The gain and noise performance of the metamorphic HEMT technology is very close to that of the InP-based HEMT     

电流增益截止频率为441 GHz的InGaAs/InAlAs InP HEMT

本文设计并制作了f_T > 400 GHz的In_0.53Ga_0.47As/In_0.52Al_0.48As 铟磷高电子迁移率晶体管（InP HEMT）。采用窄栅槽技术优化了寄生电阻。器件栅长为54.4 nm,栅宽为2 × 50 μm。最大漏极电流I_DS.max为957 mA/mm,最大跨导g_m.max为1265 mS/mm。即使在相对较小的V_DS = 0.7 V下,电流增益截止频率f_T达到了441 GHz,最大振荡频率f_max达到了299 GHz。该器件可应用于太赫兹单片集成放大器和其他电路中。     

High-speed planar-structure Inp/InGaAsP/InGaAs avalanche photodiode grown by VPE

Planar-structure InP/InGaAsP/InGaAs avalanche photo-diodes have been realised by using a VPE-growth technique and a Be+ implanted guard ring. Sensitivity measurement has been performed at 1.3 ?m and 1.8 Gbit/s. The minimum average received level required for 10?9 BER was ?31.3 dBm, which was 1.2 dB better than the value for the Ge-APD.     

超晶格雪崩光电二极管的结构优化及性能研究

基于碰撞离化理论研究了异质材料超晶格结构对载流子离化率的作用,设计得到In0.53Ga0.47As/In0.52Al0.48As超晶格结构的雪崩光电二极管。通过分析不同结构参数对器件性能的影响,得到了低隧道电流、高倍增因子的超晶格结构雪崩层,根据电场分布方程模拟了器件二维电场分布对电荷层厚度及掺杂的依赖关系,并优化了吸收层的结构参数。对优化得到的器件结构进行仿真并实际制作了探测器件,进行光电特性测试,与同结构普通雪崩光电二极管相比,超晶格雪崩光电二极管具有更强的光电流响应,在12.5~20 V的雪崩倍增区,超晶格雪崩光电二极管在具备高倍增因子的同时具有较低的暗电流,提高了器件的信噪比。     

栅长90nm的晶格匹配InAlAs／InGaAs／InP HEMT

文章报道了90nm栅长的晶格匹配InP基HEMT器件。栅图形是通过80kV的电子束直写的,并采用了优化的三层胶工艺。器件做在匹配的InAlAs／InGaAs／InP HEMT材料上。当Vds=1．0V时,两指75μm栅宽器件的本征峰值跨导达到720ms／mm,最大电流密度为500mA／mm,器件的阂值电压为．0．8V,截止频率达到127GHz,最大振荡频率达到152GHz。     

InGaAs/InAlAs multiquantum-well waveguided pin photodiodes withwide tunability and avalanche multiplication

A new high-speed, waveguided InP based on the InGaAs/InAlAs multiquantum-well pin photodiode with gain and fabricated by metal organic vapour phase epitaxy is reported. The quantum-confined Stark effect can be used to tune this diode over a 250 nm range in the wavelength region around 1.55 μm. A 3 dB bandwidth of more than 12 GHz and avalanche multiplication have been observed