绝缘栅双极型晶体管的研究进展

作为一种新型的功率半导体器件,绝缘栅双极型晶体管（IGBT）以其优越的性能,成为中高功率电力电子领域的主流功率开关器件,被广泛应用于智能电网、新能源、高速铁路、工业控制、汽车电子、家电产品、消费电子等领域。概述了IGBT的演变历程以及主要技术发展,同时对我国IGBT的发展现状进行了分析。     

绝缘栅双极晶体管(IGBT)及其应用

绝缘栅双极晶体管(IGBT)是电力电子技术中的关键器件。本文介绍了IGBT国内外发展简况,较详细地说明了IGBT的重要特性及其应用基础技术,列出了在家用电器、电焊机、电动机等方面应用的一些基本电路。     

Pt基埋栅势垒GaAs基增强型InAlAs/InGaAs改性高电子迁移率晶体管

讨论了采用埋栅结构实现Ga As基改性高电子迁移率晶体管(MHEMT)增强型模式工作的有关问题,提出了增强型MHEMT的设计与实现方法.通过不同金属(Al,Pt,Ti) / In Al As Schottky势垒系统的实验比较研究,确定在增强型MHEMT工艺中采用具有最高势垒高度的Pt Schottky埋栅结构;并进行了以最佳“推栅”温度为重点的器件工艺的深入研究.在此基础上通过实验研制的原理性1.0 μm×10 0 μm Pt栅增强型MHEMT的特性获得了夹断电压为+0 .12 V,跨导为4 70 m S/ m m及截止频率为5 0 GHz的测试结果,优于使用同一外延片制作的D-MHEMT     

Pt基埋栅势垒GaAs基增强型InAlAs/InGaAs改性高电子迁移率晶体管

讨论了采用埋栅结构实现GaAs基改性高电子迁移率晶体管(MHEMT)增强型模式工作的有关问题,提出了增强型MHEMT的设计与实现方法.通过不同金属(Al,Pt,Ti)/InAlAs Schottky势垒系统的实验比较研究,确定在增强型MHEMT工艺中采用具有最高势垒高度的Pt Schottky埋栅结构;并进行了以最佳"推栅"温度为重点的器件工艺的深入研究.在此基础上通过实验研制的原理性1.0μm×100μm Pt栅增强型MHEMT的特性获得了夹断电压为+0.12V,跨导为470mS/mm及截止频率为50GHz的测试结果,优于使用同一外延片制作的D-MHEMT.     

单片集成GaAs增强／耗尽型赝配高电子迁移率晶体管

介绍了单片集成GaAs增强／耗尽型赝配高电子迁移率晶体管（PHEMT）工艺。借助栅金属的热处理过程,形成了热稳定性良好的Pt／Ti／Pt／Au栅。AFM照片结果表明Pt金属膜表面非常平整,2nm厚度膜的粗糙度RMS仅为0．172nm。通过实验,我们还得出第一层Pt金属膜的厚度和退火后的下沉深度比大概为1：2。制作的增强型／耗尽型PHEMT的闽值电压（定义于1mA／mm）、最大跨导、最大饱和漏电流密度、电流增益截止频率分别是＋0．185／-1．22V、381．2／317．5mS／mm、275／480mA／mm、38／34GHz。增强型器件在4英寸圆片上的阈值电压标准差为19mV。     

低噪声高电子迁移率晶体管

采用直接描绘电子束刻蚀法制造了用于低噪声极高频(EHF)放大器的亚半微米栅长的高电子迁移率晶体管。调制掺杂的外延结构是用分子束外延法生长的,在10~(12)电子/cm~2的电子浓度时,室温下的霍耳迁移率为8000cm~2/V·sec,液氮温度下为77,600cm~2/V·sec。通过腐蚀通n~+GaAs接触层的凹楷的方法确定了窄达0.28μm的栅长。0.4μm栅长的耗尽型器件的直流跨导超过260mS/mm。对0.37μm栅长的器件,进行了噪声系数和相关增益的测量,在34GHz下,得到了2.7dB的噪声系数和5.9dB的相关增益。还制造了具有240mS/mm跨导的增强型器件,对0.35μm的栅长,在18GHz下,它们的噪声系数为1.5dB,相关增益为10.5dB。这些结果可以和已报导过的最好的0.25μm栅长的GaAsMESFET的噪声系数相匹敌。     

高电子迁移率晶体管放大器

<正> 美国TRW电子系统小组试制了高电子迁移率晶体管放大器,在61GHz下增益为7.5dB。该放大器使用了GaAs-GaAlAs系耗尽型高电子迁移率晶体管。栅长短到0.25μm,低频跨导是325mS/mm,源-栅间输入阻抗是0.20±0.05Ω·mm。制成混合微波IC放大器,在61GHz下获得7.5dB的增益,这个增益中包含电     

应用一种新T形栅版图设计方法的AlGaN/GaN高电子迁移率晶体管

在蓝宝石衬底上制作AlGaN/GaN高电子迁移率晶体管. 由于使用了一种全新的T形栅电子束曝光版图,因此可以自由地改变T形栅的宽窄比（T形栅头部尺寸与栅长的比值）并优化T形栅的形状. 所得的0.18μm栅长的器件,其特征频率（fT）为65GHz, T形栅的宽窄比为10. 同时,测得的峰值跨导为287mS/mm,最大电流密度为980mA/mm.     

应用一种新T形栅版图设计方法的AlGaN/GaN高电子迁移率晶体管

在蓝宝石衬底上制作AlGaN/GaN高电子迁移率品体管.由于使用了一种全新的T形栅电子束曝光版图,因此可以自由地改变T形栅的宽窄比(T形栅头部尺寸与栅长的比值)并优化T形栅的形状.所得的0.18μm栅长的器件,其特征频率(fT)为65GHz,T形栅的宽窄比为10.同时,测得的峰值跨导为287mS/mm,最大电流街度为980mA/mm.     

Depletion Mode HEMT with Refractory Metal Silicide WSi Gate

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Impact of the self-generated heat on the scalability of HEMTs

This work is aimed at studying the influence of the self-heating effect on the scalability of HEMTs from an experimental point of view. To accomplish that, we analyze the DC and microwave performance of devices having scaled gate widths.Our experimental results show that the DC transconductance does not scale linearly with the gate periphery under high power dissipation condition. The observed degradation of the transconductance in larger devices can be explained by a reduction of the average carrier velocity due to the occurrence of self-heating.Thermal phenomena even affect the RF small signal performance of the devices under test as they influence the DC operating point. Therefore, the RF transconductance and the forward transmission coefficient are degraded when the dissipated power increases so that all the self-generated heat cannot be completely removed.     

Reliability of AllnAs/lnGaAs/lnP HEMT with WSi ohmic contacts

We have investigated the degradation mechanism of Al_0.48In_0.52As/In_0.53Ga_0.47As/ InP high electron mobility transistors (HEMTs) using WSi ohmic electrodes. Cross-sectional transmission electron microscopy (TEM) observation and en-ergy dispersive x-ray (EDX) analysis reveal impurities diffusion of gate electrode (titanium: Ti) and fluorine (F) in the AlInAs layer after a high temperature (T_a = 170°C operating life test for 500 h. The decrease of drain current (I_ds) during life test shows linear dependence on square root of aging time. It suggests that the degradation is controlled by a diffusion mechanism. Hence, the estimated degradation mechanism of this device is related with decrease of carrier concentration in the epitaxial layer by these diffused impurities. On the other hand, TEM and EDX show no degradation of WSi/InGaAs interface after aging. Therefore, the WSi electrode for this type of HEMT demonstrates excellent high stability under the accelerated operating life test.     

RF and microwave characteristics of a 10 nm thick InGaN-channel gate recessed HEMT

A new depletion-mode gate recessed AlGaN/InGaN/GaN-high electron mobility transistor(HEMT)with 10 nm thickness of InGaN-channel is proposed.A growth of AlGaN over GaN leads to the formation of twodimensional electron gas(2DEG)at the heterointerface.High 2DEG density(ns)is achieved at the heterointerface due to a strain induced piezoelectric effect between AlGaN and GaN layers.The electrons are confined in the InGaN-channel without spilling over into the buffer layer,which also reduces the buffer leakage current.From the input transfer characteristics the threshold voltage is obtained as 4:5 V and the device conducts a current of 2 A/mm at a drain voltage of 10 V.The device also shows a maximum output current density of 1.8 A/mm at Vds of 3 V.The microwave characteristics like transconductance,cut-off frequency,max frequency of oscillation and Mason’s Unilateral Gain of the device are studied by AC small-signal analysis using a two-port network.The stability and power performance of the device are analyzed by the Smith chart and polar plots respectively.To our knowledge this proposed InGaN-channel HEMT structure is the first of its kind.     

Analysis of issues in gate recess etching in the InAlAs/InGaAs HEMT manufacturing process

We have developed an InAlAs/InGaAs metamorphic high electron mobility transistor device fabrication process where the gate length can be tuned within the range of 0.13 μm–0.16 μm to suit the intended application. The core processes are a two-step electron-beam lithography process using a three-layer resist and gate recess etching process using citric acid. An electron-beam lithography process was developed to fabricate a T-shaped gate electrode with a fine gate foot and a relatively large gate head. This was realized through the use of three-layered resist and two-step electron beam exposure and development. Citric acid-based gate recess etching is a wet etching, so it is very important to secure etching uniformity and process reproducibility. The device layout was designed by considering the electrochemical reaction involved in recess etching, and a reproducible gate recess etching process was developed by finding optimized etching conditions. Using the developed gate electrode process technology, we were able to successfully manufacture various monolithic microwave integrated circuits, including low noise amplifiers that can be used in the 28 GHz to 94 GHz frequency range.     

具有HEMT和MMIC的Ku波段低噪声放大器

本文介绍了由HEMT和MMIC组成的一种新颖的Ku波段低噪声放大器,放大器第一级采用了HEMT和反馈技术以同时获得噪声和增益的最佳化,讨论了这种放大器的设计,MMIC采用了二次混合微波集成,放大嚣输入和输出端均为BJ-120波导。在11.7—12.2GHz频率下,放大器噪声系数小于1.9dB,增益大于27±0.25dB,输入和输出驻波比小于1.4。     

Load-pull measurement analysis of AlGaN/GaN HEMT taking into account number of gate fingers

This paper investigates load-pull measurement of AlGaN/GaN high electron mobility transistors (HEMTs) at different numbers of gate fingers. Scalable small-signal models are extracted to analyze the relationship between each model''s parameters and the number of device''s gate fingers. The simulated S-parameters from the small-signal models are compared with the reflection coefficients measured from the load-pull measurement system at X-band frequencies of 8.8 and 10.4 GHz. The dependency between the number of device''s gate fingers and load-pull characterization is presented.     

锯齿型源漏结构的新型InP基HEMT器件

毫米波晶体管的制作技术是微波电路设计和制造的基础.从优化器件结构的角度,提出了一种锯齿型源漏的新型InP基HEMT器件.实验证明,采用这种结构可以减少光刻过程中临近效应的影响,改善源漏的图形形貌,提高器件制做的成品率.获得了具有良好直流和微波特性的晶体管,其跨导达到1050mS/mm,阈值电压为-1.0V,截止频率达到120GHz.     

A High Performance InP HEMT with Saw-Toothed Source and Drain

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低导通电阻和栅漏电的高性能InAlN/GaN HEMT

本文制备了100nm栅长的InAlN/GaN HEMT。通过氧处理和优化欧姆接触获得了高性能的InAlN/GaN HEMT。所制备的器件在栅压偏置为2V时,漏端输出电流密度达到2.18A/mm。器件的导通电阻为1.49Ω*mm。与常规器件相比,器件的栅漏电下降了两个数量级。器件也获得良好的射频特性,电流截止频率和最高震荡频率分别为81GHz和138GHz。根据现有的报道,这是国内较早报道GaN基HEMT电流密度超过2A/mm。