硅基APD器件的工艺及性能仿真分析

硅基APD 的性能取决于其器件结构与工艺过程。文中对n+-p--p+外延结构的APD 器件的工艺和器件性能进行了仿真分析,为硅基APD 器件的设计提供了理论指导。利用Silvaco 软件对APD器件的关键工艺离子注入和扩散工艺进行了仿真, 确定工艺参数对杂质的掺杂深度和掺杂分布的影响。并且,对于APD 器件的性能进行了分析,对电场分布、增益、量子效率、响应度等参数进行了仿真分析。仿真结果表明:在给定的器件参数条件下,所设计的APD器件的增益为100时,响应度峰值为55A/W左右,在600~900 nm 范围内具有较高响应度,峰值波长在810 nm。     

Ge/Si波导集成型APD器件的仿真分析

设计了一种Ge/Si波导集成型雪崩光电二极管(APD).器件采用将Si波导层置于Ge吸收层之下的结构,光经波导层进入吸收层只需一次耦合,降低了光的损耗,提高了光的吸收率和光电流.采用silvaco软件对器件的结构和性能进行仿真,结果表明:器件的雪崩击穿电压为-28 V,最大内量子效率达到89％,在1.15～1.60 μm范围内具有较高响应度,峰值波长位于1.31μm,单位响应度最高达0.74 A/W,3 dB带宽为10 GHz.     

4H-SiC 雪崩光电探测器中倍增层参数的优化模拟

应用ATLAS模拟软件,设计了吸收层和倍增层分离的（SAM）4H-SiC 雪崩光电探测器（APD）结构。分析了不同外延层厚度和掺杂浓度对器件光谱响应的影响,对倍增层参数进行优化模拟,得出倍增层的最优化厚度为0.26μm,掺杂浓度为9.0×1017cm^-3。模拟分析了APD的反向IV特性、光增益、不同偏压下的光谱响应和探测率等,结果显示该APD在较低的击穿电压66.4V下可获得较高的倍增因子105;在0V偏压下峰值响应波长（250nm）处的响应度为0.11A/W,相应的量子效率为58%;临近击穿电压时,紫外可见比仍可达1.5×103;其归一化探测率最大可达1.5×1016cmHz ^1/2 W^-1。结果显示该APD具有较好的紫外探测性能。     

基于0.35 μm高压CMOS工艺的横向线性雪崩光电二极管

提出了一种基于0.35 μm高压CMOS工艺的线性雪崩光电二极管（Avalanche Photodiode, APD）。APD采用了横向分布的吸收区-电荷区-倍增区分离（Separate Absorption, Charge and Multiplication, SACM）的结构设计。横向SACM结构采用了高压CMOS工艺层中的DNTUB层、DPTUB层、Pi层和SPTUB层,并不需要任何工艺修改,这极大的提高了APD单片集成设计和制造的自由度。测试结果表明,横向SACM线性APD的击穿电压约为114.7 V。在增益M = 10和M = 50时,暗电流分别约为15 nA和66 nA。有效响应波长范围为450 ~ 1050 nm。当反向偏置电压为20 V,即M = 1时,峰值响应波长约为775 nm。当单位增益 （M = 1） 时,在532 nm处的响应度约为最大值的一半。     

新型有机电致蓝色磷光器件的研究

设计了一种Ge/Si波导集成型雪崩光电二极管(APD)。器件采用将Si波导层置于Ge吸收层之下的结构,光经波导层进入吸收层只需一次耦合,降低了光的损耗,提高了光的吸收率和光电流。采用silvaco软件对器件的结构和性能进行仿真,结果表明:器件的雪崩击穿电压为-28V,最大内量子效率达到89%,在1.15~1.60μm范围内具有较高响应度,峰值波长位于1.31μm,单位响应度最高达0.74A/W,3dB带宽为10GHz。 更多还原     

一种基于0.18 μm CMOS工艺的高响应度

设计了一种基于0.18 μm CMOS工艺的高响应度雪崩光电二极管(APD)。该APD采用标准0.18μm CMOS工艺,设计了两个P+/N阱型pn节,形成两个雪崩区以产生雪崩倍增电流。雪崩区两侧使用STI(浅沟道隔离)结构形成保护环,有效地抑制了APD的边缘击穿;并且新增加一个深N阱结构,使载流子在扩散到衬底之前被大量吸收,屏蔽了衬底吸收载流子产生的噪声,用以提高器件的响应度。通过理论分析,确定本文所设计的CMOS-APD器件光窗口面积为10 μm×10 μm,并得到了器件其他的结构和工艺参数。仿真结果表明:APD工作在480 nm波长的光照时,量子效率达到最高90%以上。在加反向偏压-15 V时,雪崩增益为72,此时响应度可达到2.96 A/W,3 dB带宽为4.8 GHz。     

四象限InGaAs APD探测器的研究

文章中设计的四象限InGaAs雪崩光电二极管(Avalanche Photo Diode,APD)的管芯结构采用正入光式平面型结构,而材料结构采用吸收区、倍增区渐变分离的APD结构,在对响应时间、暗电流和响应度等参数进行计算与分析的基础上,优化了器件结构参数.试验结果表明,其响应时间≤1.5 ns,响应度≥9.5 A/W,暗电流≤40 nA,可靠性设计时使PN结和倍增层均在器件表面以下,可有效抑制器件表面漏电流,提高器件的可靠性.     

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.     

Si基Ge薄膜共振腔增强型光电探测器的设计与模拟

设计了Si衬底上Ge薄膜共振腔增强型光电探测器的器件结构,理论计算了上下反射镜Si/Si O2的对数、吸收区Ge薄膜的厚度、有源区面积等参数对器件的外量子效率、带宽等性能的影响。当器件上下反射镜Si/Si O2的对数分别为2和3,Ge薄膜的厚度为0.46μm,器件的台面面积小于176μm2时,探测器在中心波长1.55μm处的外量子效率达到0.64,比普通结构提高了30倍,同时器件的带宽达到40 GHz。     

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。     

A high efficient 820 nm MOS Ge quantum dot photodetector

A Ge quantum dot photodetector has been demonstrated using a metal-oxide-semiconductor (MOS) tunneling structure. The oxide film was grown by liquid phase deposition (LPD) at 50/spl deg/C. The photodetector with five-period Ge quantum dot has responsivity of 130, 0.16, and 0.08 mA/W at wavelengths of 820 nm, 1300 nm, and 1550 nm, respectively. The device with 20-period Ge quantum dot shows responsivity of 600 mA/W at the wavelength of 850 nm. The room temperature dark current density is as low as 0.06 mA/cm/sup 2/. The high performance of the photodetectors at 820 nm makes it feasible to integrate electrooptical devices into Si chips for short-range optical communication.     

1.55μmSi_(1-x)Ge_x/Si光开关与光探测器集成的分析及设计

对１．５５μｍ波长的Ｓｉ１－ｘＧｅｘ光波导开关和Ｓｉ１－ｘＧｅｘ／Ｓｉ红外探测器的集成结构进行了系统的理论分析和优化设计。设计结果为：（１）对Ｓｉ１－ｘＧｅｘ光开关，Ｇｅ含量ｘ＝０．０５，波导的内脊高、脊宽和腐蚀深度分别为３，８．５和２．６μｍ，分支角为５～６°。要实现对１．５５μｍ波长光的开关作用，ｐｎ＋结上所需加的正向偏压值应为０．９７Ｖ；（２）对Ｓｉ１－ｘＧｅｘ／Ｓｉ探测器，Ｇｅ含量ｘ＝０．５，探测器由２３个周期的６ｎｍＳｉ０．５Ｇｅ０．５和１７ｎｍＳｉ交替组成厚度为５５０ｎｍ，长度约为１．５～２ｍｍ的超晶格，内量子效率达８０％以上。     

Low-Voltage High-Speed (18 GHz/1 V) Evanescent-Coupled Thin-Film-Ge Lateral PIN Photodetectors Integrated on Si Waveguide

This letter presents the device performance of scaled thin-film-Ge lateral PIN photodetectors integrated on a Si waveguide. The photodetectors are with closely spaced p$^{+}$/n$^{+}$ regions (0.8 $mu$m) on a Ge region with short length (5–20 $mu$ m) and narrow width (2.4 $mu$m). Though with a thin Ge layer (${sim}$220 nm including bottom SiGe buffer), light is evanescent-coupled from the Si waveguide effectively to the overlying Ge detector. The device exhibits ${f}_{3 {rm dB}}$ bandwidth of 18 GHz with external responsivity of 0.13 A/W for 1550 nm at ${-}$1 V. Considering the coupling loss and waveguide loss, the internal responsivity is as high as 0.65 A/W. It is shown that with increasing detector length, the devices' internal quantum efficiency can be improved to ${sim}$ 90% and by suppressing parasitic effects, speed can be boosted further towards several tens of gigahertz.      

Ge/Si photodiodes with embedded arrays of Ge quantum dots forthe near infrared (1.3–1.5 µm) region

A method has been devised for MBE fabrication of p-i-n photodiodes for the spectral range of 1.3–1.5 µm, based on multilayer Ge/Si heterostructures with Ge quantum dots (QDs) on a Si substrate. The sheet density of QDs is 1.2×10¹² cm^?2, and their lateral size is ～8 nm. The lowest room-temperature dark current reported hitherto for Ge/Si photodetectors is achieved (2×10^?5 A/cm² at 1 V reverse bias). A quantum efficiency of 3% at 1.3 µm wavelength is obtained.     

High-mobility ultrathin strained Ge MOSFETs on bulk and SOI with low band-to-band tunneling leakage: experiments

For the first time, the tradeoffs between higher mobility (smaller bandgap) channel and lower band-to-band tunneling (BTBT) leakage have been investigated. In particular, through detailed experiments and simulations, the transport and leakage in ultrathin (UT) strained germanium (Ge) MOSFETs on bulk and silicon-on-insulator (SOI) have been examined. In the case of strained Ge MOSFETs on bulk Si, the resulting optimal structure obtained was a UT low-defect 2-nm fully strained Ge epi channel on relaxed Si, with a 4-nm Si cap layer. The fabricated device shows very high mobility enhancements >3.5/spl times/ over bulk Si devices, 2/spl times/ mobility enhancement and >10/spl times/ BTBT reduction over 4-nm strained Ge, and surface channel 50% strained SiGe devices. Strained SiGe MOSFETs having UT (T/sub Ge/<3 nm) very high Ge fraction (/spl sim/ 80%) channel and Si cap (T/sub Si cap/<3 nm) have also been successfully fabricated on thin relaxed SOI substrates (T/sub SOI/=9 nm). The tradeoffs in obtaining a high-mobility (smaller bandgap) channel with low tunneling leakage on UT-SOI have been investigated in detail. The fabricated device shows very high mobility enhancements of >4/spl times/ over bulk Si devices, >2.5/spl times/ over strained silicon directly on insulator (SSDOI; strained to 20% relaxed SiGe) devices, and >1.5/spl times/ over 60% strained SiGe (on relaxed bulk Si) devices.     

一种高带宽NP 型CMOS APD 的研究

提出了一种高带宽的硅基CMOS雪崩光电二极管(APD)器件。该器件在N阱/P衬底基本结构的基础上,增加一个N型深掩埋层,并在该掩埋层单独加上电压,以减小载流子的输运时间。通过理论分析确定了器件的结构参数,通过器件性能的仿真分析对相关参数进行了优化设计。仿真结果表明:采用标准0.18 m CMOS工艺,所设计的APD器件的窗口尺寸大小为20 m20 m,在反向偏压为16.3 V时,器件的雪崩增益为20,响应度为0.47 A/W,3 dB带宽为8.6 GHz。     

UHV/CVD生长SiGe/Si异质结构材料

以 Si2 H6 和 Ge H4 作为源气体 ,用 UHV/CVD方法在 Si( 1 0 0 )衬底上生长了 Si1- x Gex 合金材料和 Si1- x Gex/Si多量子阱结构 .用原子力显微镜、X光双晶衍射和透射电子显微镜对样品的表面形貌、均匀性、晶格质量、界面质量等进行了研究 .结果表明样品的表面平整光滑 ,平均粗糙度为 1 .2 nm;整个外延片各处的晶体质量都比较好 ,各处生长速率平均偏差为 3.31 % ,合金组分 x值的平均偏差为 2 .0 1 % ;Si1- x Gex/Si多量子阱材料的 X光双晶衍射曲线中不仅存在多级卫星峰 ,而且在卫星峰之间观察到了 Pendellosung条纹 ,表明晶格质量和界面质量都很好 ;Si     

Waveguided Ge/Si Avalanche Photodiode With Separate Vertical SEG-Ge Absorption, Lateral Si Charge, and Multiplication Configuration

A novel Si-waveguide-integrated Ge/Si avalanche photodiode (APD) is demonstrated for the first time, in which light propagating along the Si waveguide is evanescently absorbed by an overlaying Ge layer selectively grown on it, whereas the avalanche multiplication of photoexcited carriers occurs laterally in the Si-waveguide layer. The APD provides a responsivity of $sim$7.2 A/W at 1550 nm, which is $sim$26 times larger than the corresponding vertical Ge/Si p-i-n photodiode, and exhibits a 3-dB bandwidth of $sim$3.3 GHz, a dark current of $sim!hbox{22} muhbox{A}$ at 22-V bias, and an excess noise factor of $sim$4, respectively.      

A high-performance SiGe-Si multiple-quantum-well heterojunction phototransistor

A novel phototransistor is fabricated by placing Si/sub 0.5/Ge/sub 0.5//Si multiple quantum wells (MQWs) between the base and the collector of Si-SiGe heterojunction bipolar transistors (HPT). The SiGe-Si MQWs are used as a light absorption layer. The cutoff frequency (f/sub T/) and maximum oscillation frequency (f/sub MAX/) of the phototransistor are found to be 25 GHz, which is suitable for gigabit integrated circuit. The responsivity of 1.3 A/W (external quantum efficiency = 194%) and the pulsewidth of 184 ps at a wavelength of 850 nm are observed. The excellent electrical and optical performance of the Si-SiGe MQW phototransistor makes it attractive for future Si-based optoelectronic integrated circuit applications.