不同工艺制备的GaAs MESFET阈值电压均匀性研究

分别采用离子注入隔离凹栅工艺、自隔离平面工艺、离子注入隔离平面工艺在非掺杂半绝缘 Ga As衬底上制备 MESFET,对三种工艺制备的 MESFET的阈值电压均匀性进行了研究。结果表明 ,器件工艺对 MESFET阈值电压有一定的影响 ,开展 Ga As MESFET阈值电压均匀性研究应采用适宜的工艺 ,以尽可能减少工艺引起的偏差。     

不同工艺制备的GaAs MESFET阈值电压均匀性研究

分别采用离子注入隔离凹栅工艺、自隔离平面工艺、离子注入隔离平面工艺在非掺杂半绝缘GaAs衬底上制备MESFET,对三种工艺制备的MESFET的阈值电压均匀性进行了研究。结果表明,器件工艺对MESFET阈值电压有一定的影响,开展GaAs MESFET阈值电压均匀性研究应采用适宜的工艺,以尽可能减少工艺引起的偏差。     

76mm GaAs有源器件模型库

采用基于测量 S参数和直流参数的工程模型与微波在片测试技术 ,建立与76 mm Ga As工艺线直接结合的Ga As器件 (MESFET,PHEMT)的 MMIC CAD适用器件模型及模型库 ,并通过对不同种类 Ga As MMIC的设计研制进行了验证与改进 ,模拟结果和测试结果基本一致 .目前此模型和模型库已用于76 m m Ga As工艺线上多种微波 Ga As单片的设计研制 .     

微波功率GaAs MESFET本征元件与偏置关系分析

提出了一种分析和了解微波功率 Ga As MESFET非线性效应的方法。主要是采用解析优化方法 ,提取 MESFET器件在不同偏置点下的本征元件 ,并结合器件的应用类型 ,对本征元件与偏置的关系进行了系统化的分析。分析的结论有助于提高微波功率 Ga As MESFET器件设计和应用的准确性     

砷化镓衬底与MESFET中深能级研究

用波长范围为 70 0 nm到 350 0 nm的光电流测试系统研究了 SI- Ga As衬底、有源层和MESFET中的深能级。结果显示在 SI- Ga As衬底、有源层和 MESFET中的深能级有着较为密切的联系 ,这些深能级影响着器件的性能     

超高速单电源GaAs判决再生电路

设计并模拟分析了光纤通信用超高速单电源 Ga As判决再生电路 ,采用非掺 SI Ga As衬底直接离子注入、1μm耗尽型 Ga As MESFET、平面电路工艺研制出单片 Ga As判决再生电路。实验测试结果表明 ,该电路可对输入信号进行正确的“0”、“1”判决 ,并经时钟抽样后 ,输出正确的数字信号 ,传输速率可达 2 .8Gbit/s,可用于覆盖 2 .5Gbit/s系列光通信系统     

GaAs表面Ga、As的比对GaAs MESFET击穿电压的影响

通过用XPS分析GaAs MESFET肖特基势垒制作前后的表面情况,发现GaAs表面Ga、As的比,对GaAs MESFET击穿电压有着明显的影响,表面Ga、As比的明显偏离将导致击穿电压的下降.分析了GaAs表面Ga、As比偏离的原因,提出了改进的方法.     

GaAs MESFET开关模型的研究

讨论了开关 Ga As MESFET的开态模型和关态模型 ,介绍了利用高频器件建模软件 Modelling建立 Ga As MESFET开关模型的方法 ,给出了模型模拟与器件测量的曲线和模型参数。     

金-锗系统欧姆接触制备研究

对于 Ga As MESFET和以 Ga As或 In P为衬底的 PHEMT的欧姆接触制备 ,虽均采用 Au-Ge- Ni系统 ,但其合金条件却因材料特性各异而不同。     

光照对阈值电压均匀性的影响

研究了光照对砷化镓阈值电压均匀性的影响.结果表明光照使耗尽型MESFET器件的沟道电流增大,使阈值电压向负方向增加,并提高了阈值电压的均匀性.研究认为砷化镓单晶材料的深能级缺陷是影响MESFET阈值电压均匀性的重要因素之一,而光照在一定程度上减弱了这一影响.     

Damage-free reactive ion etching of GaAs FET gate recess

A GaAs reactive ion etching process is described which has good uniformity and causes no significant electrical damage to the underlying substrate. The process is shown to be suitable for forming the gate recess of a GaAs MESFET. FETs fabricated using the process exhibit DC and RF performance similar to equivalent wet etched devices.<>     

GaAs亚微米自对准工艺技术研究

总结了在５０ｍｍＧａＡｓ圆片上实现自对准介质膜隔离等平面工艺技术的研究，着重描述了离子注入、自对准亚微米难熔栅制备、钝化介质膜生长、干法刻蚀、电阻和电容制备等关键工艺的研究结果。这套工艺的均匀性、重复性好，在５０ｍｍＧａＡｓ圆片上获得了满意的成品率。采用这套工艺已成功地研制出多种性能良好的ＧａＡｓＩＣ和ＧａＡｓ功率ＭＥＳＦＥＴ，证明国家自然科学基金委员会这一重大课题的选择对发展我国ＧａＡｓＩＣ确实具有重大意义。     

A new approach to fabrication of GaAs JFETs

A new approach to JFETs is preparing gallium assenide junction field-effect transistor (JFET) presented in this paper, applying Be ion implantation for the first time along with a method of flat and homogeneous ohmic metallization. Several characteristics of FET I–V curve are also discussed.It is revealed that Be ion implantation is sufficiently feasible to obtain a buried p-type gate for the GaAs JFET. Ohmic metallization to GaAs is improved in flatness and homogeneity by simultaneous heating of substrates with Au/Ge deposition. An ion milling process for fine patterning associated with the improved metallization, proves to be useful for device micro-technology. Finally, d.c. characteristics comparable to those of the MESFET are demonstrated by the fabricated JFET, with marked advantages in the process.     

离子注入GaAs MESFET''''s的有限元二维数值分析

本文用有限元方法对离子注入 GaAs MESFET’s的稳态特性进行了二维数值模拟和分析,并与均匀掺杂器件作了比较.程序中,对边界条件、网格剖分和初值选取方法进行了改进.所开发的程序可以对不同尺寸、不同掺杂分布的平面栅、凹形栅 GaAs MESFET’s进行二维数值分析,得到其内部电位、电场、载流子浓度等物理量的二维分布和器件的I-V特性.本文还讨论了凹形栅的几何形状对器件内部电场强度的影响.最后,对实际的离子注入凹形栅GaAsMESFET进行了模拟,计算结果与实验数据基本吻合.     

High-transconductance enhancement-mode GaAs MESFET fabrication technology

An improved enhancement-mode GaAs MESFET was fabricated by a high dose Si ion implantation which was used to reduce the source and drain parasitic resistances, and by a Pt buried gate which was used to control the threshold voltage and reduce the interface states of the Schottky gate. 250 mS/mm transconductance has been obtained for 1-µm gate-length enhancement-mode GaAs MESFET.     

High speed normally-off GaAs MESFET integrated circuit

Normally-off GaAs MESFET integrated circuits with a maximum toggle frequency of 2.4 GHz were fabricated by conventional photolithography. The unfavourable effect of the surface depletion layer due to the large state density at the GaAs surface has been reduced by adopting the recessed gate FET structure.     

采用离子注入N~+层和质子隔离的12GHz 200mW功率GaAs MESFET

本文报导了采用质子隔离和Si~+离子注入N~+接触层技术,提高了功率GaAa MESFET的微波性能和可靠性.已经制成栅长1μm,总栅宽600μm的GaAs功率MESFET,12GHz下最大输出功率210mW,经严格考核表明器件具有较高的可靠性.     

A planar gate double beryllium implanted GaAs power MESFET for lowvoltage digital wireless communication application

An ion-implanted planar gate power MESFET for low voltage digital wireless communication system including DCS1800 (digital cellular system at 1800 MHz) and CDMA (code division multiple access) handset applications has been developed. The process for the device developed contains double Be implantation to reduce the surface and substrate defect trapping effects. The MESFET process developed has very little gate recess (less then 200 Å), which greatly improves the uniformity and the yield of the wafer. The 1 μm×20 mm MESFET manufactured using this planar gate technology exhibits an output power of 32.98 dBm and power added efficiency over 53% with gain of 11.2 dB when tested at 1.9 GHz under 3.6 V drain bias voltage and 80 mA quiescent drain current. The pinch off voltage of the 20 mm devices within a wafer is -2.81 V with a standard deviation of 120 mV. The device was also tested at 3.6 V and 1.9 GHz for CDMA application. Under the IS-95 CDMA modulation at 28 dBm output power, the device gain is 10.7 dB and the device has an adjacent channel power rejection (ACPR) of -29.5 dBc at 1.25 MHz offset frequency and -44.9 dBc at 2.25 MHz offset. The test data shows that the double Be implanted devices developed using the planar gate technology have very good linearity and efficiency and can be used for the low voltage DCS1800 and CDMA handset applications     

2～12GHz GaAs单片行波放大器

报道了一个全平面超宽带ＧａＡｓ单片行波放大器的研究结果。该单片电路的核心部件是四个３００μｍ栅宽的ＭＥＳＦＥＴ，整个电路拓扑结构简单，芯片面积为３．０ｍｍ×１．８ｍｍ。电路经优化设计后在２～１２ＧＨｚ范围内，小信号增益为５±１ｄＢ，输入输出电压驻波比≤１．７５。上述频率范围内输出功率≥１６ｄＢｍ，噪声系数≤８ｄＢ。采用全离子注入、全平面工艺，均匀性、一致性良好。实验结果与设计预计值十分一致。