MOS结构的软X射线辐射损伤

本文报道了MOS结构受软X射线辐照的辐射损伤的研究结果.指出,软X射线辐照将引起了 SiO_2层中正电荷及SiO_2-Si界面界面态密度的增加,而且在SiO_2体内形成电子陷阱和中性陷阱.文中还报道了辐射损伤的退火结果.     

SiC MOS界面氮等离子体改性及电学特性评价

降低SiO2/SiC界面态密度是SiCMOS器件研究中的关键技术问题。采用氮等离子体处理SiO2/SiC界面,制作MOS电容后通过I-V、C-V测试进行氧化膜可靠性及界面特性评价,获得的氧化膜击穿场强约为9.96MV/cm,SiO2/SiC势垒高度2.70eV,同时在费米能级附近SiO2/SiC的界面态密度低减至2.27×1012cm-2eV。实验结果表明,氮等离子体处理SiO2/SiC界面后能有效降低界面态密度,改善MOS界面特性。     

MOS结构热载子注入与总剂量辐照响应的相关性

通过对MOS电容进行热载子注入和总剂量辐照实验,探讨了MOS结构热载子注入与总剂量辐射响应的相关性.研究结果表明,热载子注入和总剂量辐射都会引起MOS结构的损伤,但前者产生的损伤是由于热电子注入在MOS结构的Si/SiO2系统引入氧化物负电荷引起的,后者产生的损伤是由于电离辐射在MOS结构的Si/SiO2系统感生氧化物正电荷和界面态而导致的.进一步的研究表明,针对总剂量辐射损伤采用的加固工艺,能对热电子注入感生氧化物负电荷起到非常有效的抑制作用.     

MOS结构热载子注入与总剂量辐照响应的相关性

通过对MOS电容进行热载子注入和总剂量辐照实验,探讨了MOS结构热载子注入与总剂量辐射响应的相关性. 研究结果表明,热载子注入和总剂量辐射都会引起MOS结构的损伤,但前者产生的损伤是由于热电子注入在MOS结构的Si/SiO2系统引入氧化物负电荷引起的,后者产生的损伤是由于电离辐射在MOS结构的Si/SiO2系统感生氧化物正电荷和界面态而导致的. 进一步的研究表明,针对总剂量辐射损伤采用的加固工艺,能对热电子注入感生氧化物负电荷起到非常有效的抑制作用.     

氮钝化SiC MOS界面特性的Gray-Brown法研究

降低SiO2/SiC界面态密度,尤其是SiC导带附近的界面态密度,是SiC MOS器件研究中的关键技术问题。采用氮等离子体钝化处理SiO2/SiC界面,制作成MOS电容后通过I-V和低温C-V测试进行氧化膜击穿特性及界面特性评价。氧化膜击穿电场为9.92MV/cm,SiO2与SiC之间的势垒高度为2.69eV。使用Gray-Brown法结合Hi-Lo法分析C-V曲线,获得了距导带底EC0.05～0.6eV范围内的界面态分布,其中距EC0.2eV处的界面态密度降低至1.33×1012cm-2eV-1。实验结果表明,氮等离子体处理能有效降低4H-SiC导带附近的界面态密度,改善界面特性。     

氧化后退火技术对SiO2/4H-SiC界面态密度的影响

采用等离子体增强化学气相沉积(PECVD)低温处理和高温快速退火的技术,研究了退火条件对SiO2/4H-SiC界面态密度的影响.在n型4H-SiC外延片上高温干氧氧化50 nm厚的SiO2层并经N2原位退火,随后在PECVD炉中对样品进行350℃退火气氛为PH3,N2O,H2和N2的后退火处理,之后进行高温快速退火,最后制备Al电极4H-SiC MOS电容.I-V和C-V测试结果表明,各样品的氧化层击穿场强均大于9 MV/cm,PH3处理可以降低界面有效负电荷和近界面氧化层陷阱电荷,但PH3处理样品的界面态密度比N2O处理的结果要高.经N2O氛围PECVD后退火样品在距离导带0.2和0.4 eV处的界面态密度分别约为1.7× 1012和4×1011eV-1·cm-2,有望用于SiC MOSFET器件的栅氧处理.     

MOS晶体管中辐照引起的陷阱正电荷的强压退火

电离辐射在MOS结构的SiO2层中建立正陷阱电荷,这些正陷阱电荷在正强栅偏压(+20V)下迅速减少,这是由于正栅压引起硅衬底中的电子向SiO2层隧道注入,从而与陷阱正电荷复合.正栅压退火不仅对N沟MOS结构非常有效,对P沟MOS结构也有一定的影响.给出了辐照后的NMOS和PMOS晶体管在强正栅压下退火的实验结果,阐明了正栅压下的“隧道退火”机理     

n型4H-SiC MOS电容的特性

在n型4H-SiC外延层上,采用H2,O2合成的办法,热生长30nm的SiO2层,并制备出Al栅MOS电容,完成了C-V特性的测试和分析工作,根据测试结果得出了SiO2与4H-SiC外延层的界面特性,并计算出n型4H-SiC外延层的掺杂浓度.结果表明H2,O2合成热生长的SiO2与4H-SiC外延层之间具有较好的界面特性,界面态密度较小.n型4H-SiC外延层的掺杂均匀,浓度为1.84×1017cm-3.     

SiO2/4H-SiC界面氮化退火

通过1 300℃高温干氧热氧化法在n型4H-SiC外延片上生长了厚度为60 nm的SiO2栅氧化层.为了开发适合于生长低界面态密度和高沟道载流子迁移率的SiC MOSFET器件产品的栅极氧化层退火条件,研究了不同退火条件下的SiO2/SiC界面电学特性参数.制作了MOS电容和横向MOSFET器件,通过表征SiO2栅氧化层C-V特性和MOSFET器件I-V特性,提取平带电压、C-V磁滞电压、SiO2/SiC界面态密度和载流子沟道迁移率等电学参数.实验结果表明,干氧氧化形成SiO2栅氧化层后,在1 300℃通入N2退火30 min,随后在相同温度下进行NO退火120 min,为最佳栅极氧化层退火条件,此时,SiO2/SiC界面态密度能够降低至2.07×1012 cm-2·eV-1@0.2 eV,SiC MOSFET沟道载流子迁移率达到17 cm2·V-1·s-1.     

n型4H-SiC MOS电容的特性

在n型4H-SiC外延层上,采用H2,O2合成的办法,热生长30nm的SiO2层,并制备出Al栅MOS电容,完成了C-V特性的测试和分析工作,根据测试结果得出了SiO2与4H-SiC外延层的界面特性,并计算出n型4H-SiC外延层的掺杂浓度.结果表明H2,O2合成热生长的SiO2与4H-SiC外延层之间具有较好的界面特性,界面态密度较小.n型4H-SiC外延层的掺杂均匀,浓度为1.84×1017cm-3.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.