超薄顶层硅SOI衬底上高k栅介质ZrO2的性能

采用超高真空电子束蒸发法制备了用于全耗尽SOI场效应晶体管(MOSFET)中作为高k栅介质的ZrO2薄膜.X射线光电子能谱(XPS)分析结果显示:ZrO2薄膜成分均一,为完全氧化的ZrO2,其中Zr∶O=1∶2.2,锆氧原子比偏高可能是由于吸附了空气中O2等杂质.扩展电阻法(SRP)和剖面透射电镜(XTEM)都表征出600℃退火样品清晰的ZrO2/top Si/BO/Si sub的结构,其中ZrO2/top Si界面陡直,没有界面产物生成.选区电子衍射显示薄膜在600℃快速退火后仍基本呈非晶态.研究了上述MOSOS结构的高频C-V性能,得到ZrO2薄膜的等效氧化物厚度EOT=9.3nm,相对介电常数ε≈21,平带电位VFB=-2.451eV.     

Cu/Zr-Si-N/Si金属化系统制备及退火气氛对其热稳定性的影响

采用磁控溅射法在n型〈111〉晶向的Si衬底上形成了Zr-Si-N薄膜及Cu/Zr-Si-N/Si金属化系统.将Cu/Zr-Si-N/Si金属化系统样品分别在真空及H2/N2(体积比为1∶9)气氛中800℃退火1h.对Zr-Si-N 薄膜和退火后的金属化系统样品进行X射线衍射、X射线光电子能谱、扫描电镜、薄层电阻率及俄歇电子能谱测试与分析.结果表明,Zr-Si-N阻挡层是以ZrN晶体与非晶相Si3N4或其他Si-N化合物的复合结构形式存在.经过两种气氛退火后的样品均没有发生阻挡层失效,但与真空退火相比,H2/N2退火气氛由于不存在残余O2的作用而表现出较低的Cu膜薄层电阻率及较好的Cu/Zr-Si-N/Si界面状态.     

Cu/Zr-Si-N/Si金属化系统制备及退火气氛对其热稳定性的影响

采用磁控溅射法在n型〈111〉晶向的Si衬底上形成了Zr-Si-N薄膜及Cu/Zr-Si-N/Si金属化系统.将Cu/Zr-Si-N/Si金属化系统样品分别在真空及H2/N2(体积比为1∶9)气氛中800℃退火1h.对Zr-Si-N薄膜和退火后的金属化系统样品进行X射线衍射、X射线光电子能谱、扫描电镜、薄层电阻率及俄歇电子能谱测试与分析.结果表明,Zr-Si-N阻挡层是以ZrN晶体与非晶相Si3N4或其他Si-N化合物的复合结构形式存在.经过两种气氛退火后的样品均没有发生阻挡层失效,但与真空退火相比,H2/N2退火气氛由于不存在残余O2的作用而表现出较低的Cu膜薄层电阻率及较好的Cu/Zr-Si-N/Si界面状态.     

a-SiO_x∶H/a-SiO_y∶H多层薄膜微结构的退火行为

采用 PECVD技术在 P型硅衬底上制备了 a- Si Ox∶ H/a- Si Oy∶ H多层薄膜 ,利用 AES和 TEM技术研究了这种薄膜微结构的退火行为 .结果表明 :a- Si Ox∶ H/a- Si Oy∶ H多层薄膜经退火处理形成 nc- Si/Si O2 多层量子点复合膜 ,膜层具有清晰完整的结构界面 .纳米硅嵌埋颗粒呈多晶结构 ,颗粒大小随退火温度升高而增大 .在一定的实验条件下 ,样品在 650℃下退火可形成尺寸大小合适的纳米硅颗粒 .初步分析了这种多层复合膜形成的机理     

退火温度对NiZn铁氧体薄膜性能的影响

用溶胶-凝胶(Sol-Gel)法在Si(100)基片上沉积了NiZn铁氧体薄膜,研究了退火温度对薄膜结构和磁性能的影响.XRD研究表明,薄膜具有立方尖晶石结构,但当退火温度为900 ℃时,有SiO2相出现,发生了明显的Si扩散.原子力显微镜(AFM)究表明,退火温度升高,薄膜晶粒尺寸逐渐变大,粗糙度相应增加.随着退火温度的升高,薄膜的饱和磁化强度(Ms)呈先增加后降低的趋势,而矫顽力(Hc)与Ms变化相反.当退火温度为700 ℃时,薄膜具有最优磁性能,Ms=360×103 A/m,Hc=6 764 A/m.     

光电子技术

O432005060119二氧化锆薄膜制备及其特性测量/任树喜,马洪良,徐国庆,张义炳(上海大学物理系)//强激光与粒子束.―2005,17(2).―222～224.在室温下采用电子束蒸发的办法制备二氧化锆(ZrO2)薄膜。借助紫外分光光度计、原子力显微镜(AFM)、X射线衍射(XRD)等方法研究了薄膜的透射率和表面结构,同时研究了不同退火温度对薄膜物理性质的影响,在退火温度700,900,1050℃时显微镜图像没有明显差别。随着退火温度的变大,薄膜表面的晶粒的直径逐渐变大,但粒径均在25nm左右。当退火温度达到1150℃时,粒径变得很大(约400nm)。在700,900,1050℃下退火…     

退火处理对ZnO薄膜结晶性能的影响

研究了退火处理对Zn O薄膜结晶性能的影响.Zn O薄膜由直流反应磁控溅射技术制得,并在O2 气氛中不同温度(2 0 0～10 0 0℃)下退火,利用X射线衍射(XRD)、原子力显微镜(AFM)和X射线光电子能谱(XPS)对其结晶性能进行了研究,提出了一个较为完善的Zn O薄膜退火模型.研究表明:热处理可使c轴生长的薄膜取向性增强;随退火温度的升高,薄膜沿c轴的张应力减小,压应力增加;同时晶粒度增大,表面粗糙度也随之增加.在6 4 0℃的应力松弛温度(SRT)下,Zn O薄膜具有很好的c轴取向,沿c轴的应力处于松弛状态,晶粒度不大,表面粗糙度较小,此时Zn O薄膜的结晶性能最优.     

等离子体化学气相沉积非晶SiO_x∶H(0≤x≤2.0)薄膜的红外光谱

以等离子体化学气相沉积法 (PECVD)在 30 0℃下用 Si H4和 O2 混合气体制备了非晶 Si Ox∶ H(a- Si Ox∶ H,0≤ x≤ 2 .0 )薄膜 ,并用傅里叶红外光谱 (FT- IR)测试分析了薄膜中的 Si— O— Si键红外吸收特性 .Si— O— Si伸缩振动模在 10 5 0 cm- 1和 115 0 cm- 1附近有两个吸收峰 ,而弯曲振动模在 80 0 cm- 1附近有一个吸收峰 . 10 5 0 cm- 1和115 0 cm- 1 吸收带的吸收强度之和 Isum与薄膜中的 Si原子密度 NSi之比 Isum/ NSi在氧含量 x =0— 2 .0的范围内和 x成正比 .求得氧含量比例系数 ASi O (Si— O谐振子强度的倒数 )为 1.48× 10 1 9cm- 1 .     

溶胶-凝胶法制备钡钕钛薄膜及其介电性能研究

采用溶胶-凝胶法在Si(111)和Pt/Ti/SiO2/Si衬底上制备Ba4Nd9.33Ti18O54(BNT)介质薄膜,采用X线衍射仪(XRD)和扫描电子显微镜(SEM)研究了不同退火温度对薄膜结构和表面形貌的影响。结果表明当薄膜在950℃下退火2h后具有较好结晶质量的钨青铜结构,所得到的薄膜表面较为疏松;通过掺入质量分数为2%B2O3-2SiO2,可进一步将BNT薄膜的晶化温度降至900℃,且结构致密。介电性能测试表明,1 MHz频率下BNST薄膜的介电常数为45,介电损耗为1.1%,30V偏压下漏电流密度为4.13×10-6 A/cm2。     

退火温度对 BNST薄膜结构和性能的影响

采用射频磁控溅射法在Pt/Ti/LaAlO3(100)衬底上制备了BaO-Nd2O3-Sm2O3-TiO2系(BNST)薄膜.研究了退火温度对BNST薄膜结构、表面形貌和介电性能的影响.X线衍射仪(XRD)分析表明,随着退火温度的升高,晶粒逐渐长大.经850℃退火处理的BNST薄膜具有很好的结晶质量.原子力显微镜(AFM)分析表明,在一定范围内提高退火温度所制备的薄膜晶粒致密、大小均匀.LCR测试分析表明,在测试频率为100 kHz时,随着退火温度的升高,BNST薄膜介电常数有所增加,介电损耗则先降低,后增加.实验表明,经850℃退火处理,所制备的BNST薄膜的介电常数达37,介电损耗小于1.2‰.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

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