在光电探测器PTCDA/P-Si芯片的有机层表面,成功制作出了比接触电阻为4.5×10-5Ω·cm2的低阻欧姆接触层。利用X射线光电子能谱(XPS)对Al/Ni/ITO的欧姆接触层界面的电子状态进行了测试和分析。结果表明,ITO中的In3d及Sn3d各出现两个分裂能级的谱峰,它们是In和Sn原子处于氧化环境的结合能。Ni2p有两个谱峰Ni2p(1)及Ni2p(2),低结合能位置Ni2p(1)对应于Ni原子被X射线激发产生的谱峰,说明NiITO之间没有发生化学反应,Ni层阻止了Al层被氧化成Al2O3;高结合能Ni2p(2)谱峰说明已形成了Al3Ni冶金相,有利于低阻欧姆接触层的形成。

Low Ohmic contact layers with the specific contact resistance of 4. 5í10 -5Ω·cm2 were fabricated on the organic layer surface of PTCDA/P-Si photodetector chip. The electronic states of the interface of Al/Ni/ITO structure Ohmic contact layer were investigated using X-ray photoelectron spectroscopy ( XPS) . In ITO, In3d and Sn3d arise two peaks of split level, respectively. They are the binding energy of In and Sn atom located in oxidizing environment. Ni2p has two spectra peaks of Ni2p(1) and Ni2p(2) . The lower binding energy location is Ni2p(1) which is excited by X-ray. It indi-cates that no chemical reaction happens between Ni and ITO layer, and the formation of A12 O3 has been prevented. As for Ni2p(2) peak, it indicates that Al3 Ni alloy phase has formed,which is good for the formation of low resistance Ohmic contact layer.

本文制备了AlGaN/GaN HEMT器件中常规结构与带有纵向接触孔结构的两种接触电极,研究了该两种源欧姆接触模式对器件电学特性的影响.在相同条件下进行快速退火,发现在750?C下退火30 s后,常规结构还没有形成欧姆接触,而带有纵向欧姆接触孔的接触电极与外延片已经形成了良好的欧姆接触.同时,比较了Ti/Al/Ti/Au和Ti/Al/Ni/Au电极退火后表面形态,Ti/Al/Ni/Au具有更好的表面形貌.通过测试两种结构的HEMT器件后,发现采用纵向欧姆接触孔结构器件具有更高的跨导和饱和电流,但是也会在栅极电压为0.5—2 V之间产生严重的电流崩塌现象.

In this paper, the AlGaN/GaN HEMT (high electron mobility transistors) with different ohmic contact structures are fabricated, and the effect of different ohmic contact pattern on GaN HEMT electrical properties is studied. A conventional ohmic contact electrode structure and a new ohmic contact structure with a contact hole are fabricated and subjected to rapid thermal annealing (RTA) in flowing N2. After different structured AlGaN/GaN HEMTs are annealed at 750 ?C for 30 seconds, in HEMTs with a conventional structure ohmic contact still does not form while in the device with ohmic contact holes a good ohmic contact is already formed. Then the surface morphology of different multilayer electrode structures is measured. Comparing Ti/Al/Ti/Au with Ti/Al/Ni/Au, we can conclude that the structure Ti/Al/Ni/Au has a more smooth surface after annealing. After testing the HEMT devices with different structures, higher transconductance and saturation current are found for the devices with ohmic

本文通过对电容式微机械加速度传感器的原理进行分析,针对影响传感器性能的非欧姆接触因素进行分析,从而进行关于微机械加速度传感器的温度补偿电路设计,通过稳定性测试手段来验证本文设计的可靠性与可行性。

Based on the capacitive micromachined accelerometer principle analysis,analysis of non-ohmic contact sensor performance factors for,so be on the micromechanical acceleration sensor temperature compensation circuit design,through stability testing methods to verify the reliability of the design of this article and feasibility.

为了进一步提高氢化非晶硅薄膜晶体管(a-Si：H TFT)的场效应电子迁移率,研究了批量生产条件下对欧姆接触层和栅极绝缘层进行多层制备,不同的工艺参数对 a-Si：H TFT 场效应电子迁移率的影响.研究表明随着对欧姆接触层(n+层)分层数的增加,以及低速生长的栅极绝缘层(GL 层)和高速生长的栅极绝缘层(GH 层)厚度比值提高, a-Si：H TFT 的场效应迁移率得到提升.当 n+层分层数达到3层, GL 层和 GH 层厚度比值为4：11时,器件的场效应电子迁移率达到0.66 cm2/V·s,比传统工艺提高了约一倍,显著改善了 a-Si：H TFT 的电学特性,并在量产线上得到了验证.

The amorphous silicon TFT (α-Si thin film transistor) were fabricated in a new structure, in which the ohmic contact layer (n+layer) and the nitride silicon insulating layer for grid (G-SiNx) were stratified. Various factors which affect the electron mobility ofα-Si TFT are studied using orthogonal test. With the increase in the number of n+ layer, the electronic mobility also rises. Besides, G-SiNx should be stratified into a rapid deposition film (GH) and a low-speed growing film (GL). The thickness of GL should be increased, with the thickness of GH reduced accordingly to achieve the electron mobility gradually increasing. Finally, based on the experimental results in the orthogonal combination experiments, the α-Si TFT mobility can stably reach 0.66 cm2/V·s, much higher than the traditional volume production data (0.29 cm2/V·s).

研究了不同Ni厚度的Ni/Ag/Ti/Au电极在不同退火温度和退火气氛下与p-GaN之间的欧姆接触性能以及电极的光反射率的变化.采用矩形传输线模型对各电极的比接触电阻率进行测算,利用分光光度计对电极在不同波长下的反射率进行测量.结果表明,Ni金属层的厚度越小,电极的光反射率越高,而Ni层厚度对比接触电阻率的影响较小;当退火温度高于400℃后,电极的光反射率降低,在氧气氛围中退火后光反射率比在氮气中退火后下降更加明显.但在氧气氛围中退火有利于减小比接触电阻率.综合考虑接触电阻和光反射率,电极Ni(1 nm)/Ag/Ti/Au在400℃氧气中快速退火后得到了较好的结果,其比接触电阻率为5.5×10-3Ω·cm2,在450 nm处反射率为85%.利用此电极制作了垂直结构发光二极管(LED)器件,LED在350 mA注入电流下,工作电压为3.2 V,发光功率为270 mW,电光转换效率达到24%.

The ohmic reflectivity of Ni/Ag/Ti/Au in contact with p-GaN is studied. It is found that under different thickness values of Ni, different annealing temperatures and different annealing atmospheres, the performances of Ni/Ag/Ti/Au electrode are greatly changed. The contact resistivity is measured using the transmission line model. The reflectivity of the electrode is investigated by using a spectrophotometer. The results reveal that the thinner the Ni metal layer, the higher its reflectivity is, in addition, the thickness value of Ni metal has a little influence on contact resistivity. There appears an abrupt decrease in reflectivity of electrode after annealing at a temperature higher than 400 ?C. It is noticed that the reflectivity decreases more sharply after annealing in oxygen atmosphere than in nitrogen atmosphere. However, annealing in oxygen atmosphere is more helpful to reduce the contact resistivity. The comprehensive evaluations of the contact resistivity and reflectivity in