首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
叙述了采用国产 MBE 装置,在 GaAs 或 InSb 衬底上生长 InSb,InAsSb薄膜材料一些基础研究工作。采用二步生长法在 GaAs 衬底上生长优质 InSb 薄膜,厚度4.8μm,其室温迁移率达到4.3×10~4cm~2V·s,载流子浓度为2.4×10~(18)cm~(-3),77K 时载流子浓度为7.49×10~(15)cm~(-3);并在生长各种类型 InAsSb 超晶格材料的基础上,首次生长了 InAs_(0·05)Sb_(0·95)/InSb 应变层超晶格结构材料,其周期厚度为21nm,InSb 应变层与 InSb 层之间的共格度为0.65,本文还将叙述制作 InAsSb 长波红外探测器的具体工艺及其一些想法。  相似文献   

2.
我们利用普通的液相外延(LPE)技术在n~+-GaAs衬底上制得均匀性良好的高质量四层外延片:第一层n-GaAlAs,厚25μm,载流子浓度为~1×10~(18)cm~(-3),第二层GaAs,有  相似文献   

3.
利用Se电化学喷射炉产生的Se分子束,对分子束外延(MBE)GaAs掺杂,获得了载流子浓度为 10~(15)-10~(15)cm~(-3)的N型 GaAs. 载流子浓度 8.0 ×10~(15)-5.76 × 10~(15)cm~(-3)范围相应的室温迁移率为6350-5200cm~2/V·s.还研究了各种生长参数对载流子浓度的影响.对实验结果给予了定性的解释.  相似文献   

4.
使用MOCVD技术生长GaAs,结果表明,纯度GaAs中起支配作用的电活性杂质是C和Si。综合C和Si的作用,建立了简单的热力学模型,得到As/Ga比对载流子类型和浓度影响的解析表达式,并且与实验结果符合得很好。生长的GaAs外延层室温载流子浓度为9×10~(14)cm~(-3),迁移率为5100cm~2/V·s。  相似文献   

5.
MBE GaAs单晶薄膜的载流子浓度(1.8-8)×10~(16)cm~(-3),室温迁移率 3000-5000cm~2/V.3最高达5466cm~2/V.s,相应的77K迁移率为1.59 ×10~4cm~2/V.s.对高杂质浓度的外延层进行了阴极荧光(4.2K) 和SIMS 测量分析.  相似文献   

6.
<正> 制作平面Gunn畴雪崩器件的材料是在掺Cr的高阻GaAs衬底上汽相外延一层n-GaAs,其电子浓度为1×10~(15)~1×10~(18)cm~(-3),厚度为6~15μm,迁移率为4000~7500cm~2/V·s。在这样的材料上生长SiO_2,常压下,当衬底温度大于630℃时,由于As的升华,使GaAs的晶体完整性受到损坏,而在较低温度下(如420~450℃)淀积时,SiO_2常出现破裂或脱落现象。 GaAs的热膨胀系数为5.9×10~(-6)℃~(-1),而SiO_2为0.4×10~(-6)℃~1,相差一个数量级以上;此外,SiO_2的应力,300K时为1~6×10~3N/cm。实验表明,在GaAs上淀积的SiO_2厚度超过5000(?)时便产生破裂。而P_2O_5在GaAs上淀积1500(?),却未观察到裂纹,因为P_2O_5的热  相似文献   

7.
<正> 日本电子综合技术研究所最近试制了一种以GaAs作栅材料的自对准增强型FET—SISFET,获得了均匀的阈值电压。制作方法是:在半绝缘GaAs衬底上,用分子束外延方法连续生长非掺杂的GaAs(1.35μm)、非掺杂的Al_(0.4)Ga_(0.6)As(4nm)、掺硅的N~+-GaAs(0.5μm)。掺硅层的载流子浓度为1×10~(18)cm~(-3),生长温度约为690℃,GaAs层的生长速度为0.68μm/h,AlGaAs层的为  相似文献   

8.
磷化铟汽相外延已用于沉积制备 FET 所需的亚微米多层结构。该结构是沉积在绝缘掺铁衬底上,由缓冲层、表面沟道层和 n~(++)接触层组成。缓冲层之 N_d-N_d<10~(14)cm~(-3)、μ_(77°K)>50,000cm~2/v·s。表面沟道层掺硫,其厚度为0.3~0.5μm,载流子浓度控制在8×10~(16)cm~(-3)到2×10~(17)cm~(-3),相应的298°K 电子迁移率为3900cm~2/v·s 和3000cm~2/v·s,并且没有观察到性能随沟道层的减薄而退化的现象。由于材料具有极好的横向均匀性,从而用实验证明了生长 n~(++)层能使接触电阻减少以及采用隐埋沟道能引起栅的改善。发展了用于测量载流子浓度分布的金属-氧化物-半导体技术,当FET 的沟道掺杂浓度为2×10~(17)cm~(-3)时,用这种技术能提供6000(?)的耗尽。  相似文献   

9.
MCT液相外延薄膜的生长和特性   总被引:1,自引:1,他引:0  
王跃  汤志杰 《红外技术》1991,13(1):6-10
用开管水平液相外延系统从富Te溶剂中生长了不同x值的MCT薄膜。经X射线衍射、Hall电学参数、红外光谱、扫描电镜、X射线能谱仪和电子通道花样分析测试,结果表明:外延薄膜表面平整,光学参数较好,纵向、横向组份均匀,晶体结构完整,电学参数较好,外延膜质量优良。短波材料(n型):载流子浓度3.54×10~(14)cm~(-3),迁移率1.63×10~4cm~2V~(-1)s~(-1);中波材料(n型):载流子浓度9.95×10~(14)cm~(-3),迁移率为1.76×10~4cm~2V~(-1)s~(-1);原生长波材料(n型):载流子浓度为2.15×10~(15)cm~(-3),迁移率2.00×10~4cm~2V~(-1)s~(-1)。  相似文献   

10.
首先用正规溶液模型,在650~700℃间计算了In_(0.53)Ga_(0.47)As的液相组分。通过实验调整,在653℃、684℃和701℃LPE生长了与(100)InP衬底晶格匹配的非故意掺杂三元合金In_(0.53)Ga_(0.47)As,并测量了其外延层的载流子浓度、霍尔迁移率和电阻率。684℃生长的外延层具有光滑的表面彤貌,室温下其载流子浓度为3.7×10~(15)cm~(-3),霍尔迁移率为9.07×10~3cm~2/v·s,电阻率为0.19Ω—cm。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号