一种新的高成品率InP基T型纳米栅制作方法

提出了一种新的PMMA/PMGI/PMMA三层胶复合结构,通过一次对准和电子束曝光、多次显影在InP PHEMT材料上制作出高成品率的T型纳米栅.在曝光显影条件变化20%的情况下,InP HEMT成品率达到80%以上;跨导变化范围在590～610mS/mm,夹断电压为-1.0～-1.2V,器件的栅长分布均匀.这种新的结构工艺步骤少,工艺宽容度大,重复性好,大大提高了纳米栅器件的成品率.     

88 nm栅长fmax＝201 GHz InP基In0.53Ga0.47As/In0.52Al0.48As HEMT器件

我们成功研制了栅长88 nm, 栅宽2 50 μm, 源漏间距为2.4 μm 的InP基In0.53Ga0.47As/In0.52Al0.48As高电子迁移率器件(HEMT)。栅是使用PMMA/Al/UVⅢ,通过优化电子束曝光时间及其显影时间的方式制作的。这些器件有比较好的直流及其射频特性：峰值跨导、最大源漏饱和电流密度、开启电压、ft和fmax 分别为765 mS/mm, 591 mA/mm, -0.5 V, 150 GHz 和201 GHz。这些器件将非常适合于毫米波段集成电路。     

120nm栅长晶格匹配InGaAs/InAlAs HEMTs 器件研制

利用新型的PMMA/PMGI/ZEP520/PMGI四层胶电子束光刻胶研制出一种性能卓越的T型栅,该T型栅栅头宽980纳米,栅脚宽120纳米,有效地减小了栅的寄生电阻和电容效应, 增强了器件的高频特性。利用该T型栅工艺制备出的120nm栅长晶格匹配In0.53Ga0.47As/In0.52Al0.48As InP基HEMT器件获得了优越的直流和高频性能,电流增益截止频率和最大单向功率增益频率分别达到190 GHz 及 146 GHz。文中的材料结构和所有器件制备均为本研究小组自主研究开发。     

PMMA的离子束曝光特性

用B~+、F~+离子束曝光PMMA,实验得到灵敏度为(1-8)×10~(12)离子/厘米~2,饱和曝光深度t由能量损失的深度分布范围决定,且t≌R_p+2△R_p,阈值能量8_m=(30-330)焦耳/厘米~3,并估算了本实验条件下离子束曝光PMMA的分辨率d～(25-100)纳米.XPS分析结果表明,在剂量D>1×10~(13)离子/厘米~2时,PMMA表层中含氧量才显著减少,由此推想在离子束曝光常用剂量范围内,PMMA发生降解反应时并不伴随含氧侧基的脱落.     

用X光光刻法制备亚波长抗反射结构

为了提高太阳电池的转换效果,降低反射光栅的偏振敏感性,开发了一种新的抗反射结构的微细加工技术.首先用X光光刻在PMMA光刻胶上得到相应的亚微米级的线宽图形,再利用显影技术获得了高深宽比的立体亚波长纳米结构,即抗反射结构.设计了适用于可见光波段的二维亚波长抗反射光栅,用X光光刻制作工艺在硅衬底上进行了实验制备.用此纳米加工技术获得了线宽为150 nm、高度约为450 nm(即深宽比为3.O)的PMMA减反射结构.同时还优化了曝光近接间隔、曝光剂量、显影时间等X光光刻参数.     

亚微米尺寸金属电极的制备工艺

亚微米尺寸金属电极在高电子迁移率晶体管(HEMT)等半导体电子学器件中有重要应用,其制作是器件制作中的关键工艺,对器件性能有着重要影响。本文选择合适的涂胶旋转转速、烘烤温度(180℃)和时间,可以有效地减少电子束曝光后所产生的气泡。通过对聚甲基丙烯酸甲酯/聚二甲基戊二酰亚胺(PMMA/PMGI)双层胶进行电子束曝光和显影,确定了合适的曝光剂量为550 μC/cm2。通过调整显影液配比,并将显影时间控制在合理范围,获得了光滑完整的PMMA/PMGI双层光刻胶曝光图形。开发了双层光刻胶电子束曝光工艺,制备出宽度为200 nm的金属电极。     

聚合物栅绝缘层厚度对并五苯有机场效应管性能的影响

采用不同厚度的聚甲基丙烯酸甲酯(PMMA)作为栅绝缘层,制备了并五苯有机场效应晶体管(OFET)。测量了不同厚度的PMMA的介电特性,并详细分析了栅绝缘层厚度对器件性能的影响。其中,采用260nm厚的PMMA栅绝缘层的OFET具有比采用其它厚度的器件更优越的性能,其场效应迁移率、阈值电压与开关电流比分别达到3.39×10-3 cm2/Vs、-19V和103。     

增强型InGaP/AlGaAs/InGaAs PHEMT栅退火工艺

针对InGaP/AlGaAs/lnGaAs PHEMT器件,进行了Ti/Pt/Au和Pt/Ti/Pt/Au两种栅金属结构的退火实验,通过实验研究比较,得到了更适用于增强型器件的退火工艺,利用Ti/Pt/Au结构,在320℃退火40min,使器件阈值电压正向移动大约200mV,从而成功制作了高成品率的稳定一致的增强型器件,保证了增强型器件阈值电压在零以上.     

增强型InGaP／AlGaAs／InGaAs PHEMT栅退火工艺

针对InGaP/AlGaAs/lnGaAs PHEMT器件,进行了Ti/Pt/Au和Pt/Ti/Pt/Au两种栅金属结构的退火实验,通过实验研究比较,得到了更适用于增强型器件的退火工艺,利用Ti/Pt/Au结构,在320℃退火40min,使器件阈值电压正向移动大约200mV,从而成功制作了高成品率的稳定一致的增强型器件,保证了增强型器件阈值电压在零以上.     

0.25μm GaAs基MHEMT器件

采用普通接触曝光研制成栅长为0 .2 5 μm的Ga As基In Al As/ In Ga As变组分高电子迁移率晶体管(MHEMT) ,测得其跨导为5 2 2 m S/ m m,沟道电流密度达4 90 m A/ mm,截止频率为75 GHz,比同样工艺条件下Ga As基In Ga P/ In Ga As PHEMT的性能有很大的提高.对该器件工艺及结果进行了分析,提取了器件的交流小信号等效电路模型参数,并提出了进一步得到高稳定性、高性能器件的方法.     

200nm栅长In0.52Al0.48As/In0.6Ga0.4As MHEMTs器件

利用电子束光刻技术制备出200nm栅长GaAs基InAlAs/InGaAs MHEMT器件.Ti/Pt/Au蒸发作为栅极金属.同时为了减少栅寄生电容和寄生电阻,采用3层胶工艺,实现了T型栅.GaAs基MHEMT 器件获得了优越的直流和高频性能,跨导、饱和漏电流密度、域值电压、电流增益截止频率和最大振荡频率分别达到510mS/mm,605mA/mm,-1.8V,110GHz及72GHz,为进一步研究高性能GaAs基MHEMT器件奠定了基础.     

200nm栅长In0.52Al0.48As／In0.6Ga0.4As MHEMTs器件

利用电子束光刻技术制备出200nm栅长GaAs基InAIAs/InGaAs MHEMT器件.Ti/Pt/Au蒸发作为栅极金属.同时为了减少栅寄生电容和寄生电阻,采用3层胶工艺,实现了T 型栅. GaAs基MHEMT 器件获得了优越的直流和高频性能,跨导、饱和漏电流密度、域值电压、电流增益截止频率和最大振荡频率分别达到510mS/mm, 605mA/mm, -1.8V, 110GHz及 72GHz，为进一步研究高性能GaAs基MHEMT器件奠定了基础.     

High DC and microwave characteristics of subhalf-micrometre gate ion-implanted GaAs MESFETs using trilayer deep UV lithography

Subhalf-micrometre gate length ion-implanted GaAs MESFETs have been fabricated on 3 inch diameter substrates using trilayer deep UV lithography. Implanted MESFETs with 0.3 mu m gate lengths exhibit a maximum extrinsic transconductance of 205 mS/mm at a drain current of 600 mA/mm. From S-parameter measurements, a current gain cutoff frequency f/sub t/ of 56 GHz and a maximum available gain cutoff frequency f/sub max/ greater than 90 GHz are achieved. The gate-to-drain diode characteristics of the devices show a sharp breakdown voltage of 13-15 V. The high drain current-drain voltage and microwave characteristics indicate that ion-implanted technology with trilayer deep UV lithography has potential for the manufacture of power devices and amplifiers for Q-band communication applications. This is the first reported result using trilayer deep UV lithography to demonstrate both f/sub t/ over 56 GHz and 13-15 V gate-to-drain breakdown on 0.3 mu m gate-length ion-implanted GaAs MESFETs.<>     

0.4-µm gate-length devices fabricated by contrast-enhanced lithography

This letter describes the fabrication of submicrometer polysilicon-gate MOS devices by an advanced optical process called contrast enhancement. Functional devices having gate lengths as small as 0.4 µm were fabricated with this process. Contrast-enhanced lithography (CEL) allows usable photoresist patterns to be fabricated at smaller dimensions than is possible with conventional resist. The simultaneous replication of mask dimensions for isolated lines at 0.35 µm and above was achieved in this work using a single exposure on an Optimetrix 10:1 DSW system. Contrast enhancement has been applied to the fabrication of n-channel MOS devices having gate lengths from 0.4 to 1.5 µm in steps of 0.1 µm. Long-channel devices were also fabricated. The transconductance of the 0.4-µm devices is 40 mS/mm at Vds= 5 V. Threshold voltages (Vds= 0) are nearly independent of gate length, ranging from 1.21 to 1.31 V over the 7.5- to 0.4-µm range in gate length. The effective mobility for long-channel devices is 430 cm²/V.s.     

120-nm gate-length In0.7Ga0.3As/In0.52Al0.48As InP-based HEMT

120 nm gate-length In_(0.7)Ga_(0.3)As/In_(0.52)Al_(0.48) As InP-based high electron mobility transitions(HEMTs) are fabricated by a new T-shaped gate electron beam lithograph(EBL) technology,which is achieved by the use of a PMMA/PMGI/ZEP520/PMGI four-layer photoresistor stack.These devices also demonstrate excellent DC and RF characteristics:the transconductance,maximum saturation drain-to-source current,threshold voltage,maximum current gain frequency,and maximum power-gain cutoff frequency of InGaAs/I...     

120nm栅长In0.7Ga0.3As/In0.52Al0.48As HEMTs 器件

利用新型的PMMA/PMGI/ZEP520/PMGI四层胶T形栅电子束光刻技术制备出120nm栅长InP基雁配In0.7Ga0.3As/In0.52Al0.48As 高电子迁移率晶体管。制作出的InP基HEMT器件获得了良好的直流和高频性能,跨导、饱和漏电流密度、阈值电压、电流增益截止频率和最大单向功率增益频率分别达到520 mS/mm, 446 mA/mm, -1.0 V, 141 GHz 及 120 GHz。文中的材料结构和所有器件制备均为本研究小组自主研究开发。     

AlGaAs／InGaAs功率PHEMT用异质材料的计算机优化与器件实验结果

借助一新的工艺模拟与异质器件模型用ＣＡＤ软件──ＰＯＳＥＳ（Ｐｏｉｓｓｏｎ－ＳｃｈｒｏｅｄｉｎｇｅｒＥｑｕａｔｉｏｎＳｏｌｖｅｒ），对以ＡｌＧａＡｓ／ＩｎＧａＡｓ异质结为基础的多种功率ＰＨＥＭＴ异质层结构系统（传统、单层与双层平面掺杂）进行了模拟与比较，确定出优化的双平面掺杂ＡｌＧａＡｓ／ＩｎＧａＡｓ功率ＰＨＥＭＴ异质结构参数，并结合器件几何结构参数的设定进行器件直流与微波特性的计算，用于指导材料生长与器件制造。采用常规的ＨＥＭＴ工艺进行ＡｌＧａＡｓ／ＩｎＧａＡｓ功率ＰＨＥＭＴ的实验研制。对栅长０．８μｍ、总栅宽１．６ｍｍ单胞器件的初步测试结果为：ＩＤｓｓ２５０～４５０ｍＡ／ｍｍ；ｇｍ０２５０～３２０ｍＳ／ｍｍ；Ｖｐ－２．０－２．５Ｖ；ＢＶＤＳ５～１２Ｖ。７ＧＨｚ下可获得最大１．６２Ｗ（功率密度１．０Ｗ／ｍｍ）的功率输出；最大功率附加效率（ＰＡＥ）达４７％。     

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。     

高性能1mm AlGaN/GaN功率HEMTs研制

报道了基于蓝宝石衬底的高性能1mm AlGaN/GaN HEMTs功率器件.为了提高微波功率器件性能，采用新的欧姆接触和新型空气桥方案．测试表明，器件电流密度为0.784A/mm，跨导197mS/mm，击穿电压大于40V，截止态漏电较小，1mm栅宽器件的单位截止频率达到20GHz，最大振荡频率为28GHz，功率增益为11dB，功率密度为1.2W/mm,PAE为32%,两端口阻抗特性显示了在微波应用中的良好潜力．     

Quantum-well p-channel AlGaAs/InGaAs/GaAs heterostructureinsulated-gate field-effect transistors with very high transconductance

Quantum-well p-channel pseudomorphic AlGaAs/InGaAs/GaAs heterostructure insulated-gate field-effect transistors with enhanced hole mobility are described. The devices exhibit room-temperature transconductance, transconductance parameter, and maximum drain current as high as 113 mS/mm, 305 mS/V/mm, and 94 mA/mm, respectively, in 0.8-μm-gate devices. Transconductance, transconductance parameter, and maximum drain current as high as 175 mS/mm, 800 mS/V/mm, and 180 mA/mm, respectively were obtained in 1-μm p-channel devices at 77 K. From the device data hole field-effect mobilities of 860 cm²/V-s at 300 K and 2815 cm²/V-s at 77 K have been deduced. The gate current causes the transconductance to drop (and even to change sign) at large voltage swings. Further improvement of the device characteristics may be obtained by minimizing the gate current. To this end, a type of device structure called the dipole heterostructure insulated-gate field-effect transistor is proposed