The growth of high-Al-content InAlGaN quaternary alloys by RF-MBE

High-Al-content InxAlyGa1-x-yN (x = 1-10%, y = 34-45%) quaternary alloys were grown on sapphire by radio-frequency plasma-excited molecular beam epitaxy. Rutherford back-scattering spectrometry, high resolution x-ray diffraction and cathodoluminescence were used to characterize the InAlGaN alloys. The experimental results show that InAlGaN with an appropriate Al/In ratio (near 4.7, which is a lattice-match to the GaN under-layer) has better crystal and optical quality than the InAlGaN alloys whose Al/In ratios are far from 4.7. Some cracks and V-defects occur in high-Al/In-ratio InAlGaN alloys. In the CL image, the cracks and V-defect regions are the emission-enhanced regions.

Effects of ZnO interlayers on thick GaN/Si film prepared by RF magnetron sputtering

We have successfully prepared a high-quality 2 mu m-thick GaN film with three inserted 30 nm-thick ZnO interlayers on Si (111) substrate without cracks by magnetron sputtering. The effects of the thickness and number of ZnO interlayers on the crystal quality of the GaN films were studied. It was found that the GaN crystal quality initially improved with the increase of the thickness of ZnO interlayers, but deteriorated quickly when the thickness exceeded 30 nm. Multiple ZnO interlayers were used as an effective means to further improve the crystal quality of the GaN film. By increasing the number of interlayers up to three, the cracks can be constrained to a certain extent, and the crystal quality of the GaN film greatly improved. (c) 2006 Elsevier B.V. All rights reserved.

Fabrication and properties of Sb-doped ZnO thin films grown by radio frequency (RF) magnetron sputtering

Sb-doped and undoped ZnO thin films were deposited on Si (100) substrates by radio frequency (RF) magnetron sputtering. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses revealed that all the films had polycrystalline wurtzite structure and c-axis preferred orientation. Room temperature Hall measurements showed that the as-grown films were n-type and conducting (rho similar to 1-10 Omega cm). Annealing in a nitrogen ambient at 400 degrees C for 1 h made both samples highly resistive (rho > 10(3) Omega cm). Increasing the annealing temperature up to 800 C, the resistivity of the ttndoped ZnO film decreased gradually, but it increased for the Sb-doped ZnO film. In the end, the Sb-doped ZnO film annealed at 800 C became semi-insulating with a resistivity of 10(4)Omega cm. In addition, the effects of annealing treatment and Sb-doping on the structural and electrical properties are discussed. (c) 2006 Elsevier B.V. All rights reserved.

Photoluminescence of nanocrystalline SiC films prepared by rf magnetron sputtering

Amorphous Sic films are deposited on Si (111) substrates by rf magnetron sputtering and then annealed at 1200 degreesC for different times by a dc self-heating method in a vacuum annealing system. The crystallization of the amorphous Sic is determined by Raman scattering at room temperature and X-ray diffraction. The experimental result indicates that the Sic nanocrystals have formed in the films. The topography of the as-annealed films is characterized by atomic force microscopy. Measurements of photoluminescence of the as-annealed films show blue or violet light emission from the nanocrystalline Sic films and photoluminescence peak shifts to short wavelength side as the annealing time decreases.

An integrated optical receiver in MS/RF CMOS process

A monolithically integrated optoelectronic receiver was realized utilizing a deep sub-micron MS/RF CMOS process. Novel photo-diode with STI and highspeed receiver circuit were designed. This OEIC takes advantage of several new features to improve the performance.

MS/RF CMOS工艺兼容的光电探测器模拟与测试

设计了一种新型的与MS/RF CMOS工艺全兼容、带深n阱(DNW)、浅沟槽隔离(STI)的双光电探测器,分析了其工作机理,用器件模拟软件ATLAS对其暗电流、响应电流、光调制频率响应和波长响应进行了模拟.采用TSMC 0.18 μm MS/RF CMOS工艺进行了流片,对芯片进行了暗电流和响应度的测试.模拟和测试结果均表明,该探测器与常规双光电探测器相比,具有较低的暗电流和较高的响应度.

Layout Design and Optimization of RF Spiral Inductors on Silicon Substrate

The effects of key geometrical parameters on the performance of integrated spiral inductors are investigated with the 3D electromagnetic simulator HFSS. While varying geometrical parameters such as the number of turns （N）,the width of the metal traces （W）,the spacing between the traces （S）,and the inner diameter （ID）, changes in the performance of the inductors are analyzed in detail. The reasons for these changes in performance are presented. Simulation results indicate that the performance of an integrated spiral inductor can be improved by optimizing its layout. Some design rules are summarized.

蓝宝石衬底上单晶InAlGaN外延膜的RF-MBE生长

利用射频等离子体辅助分子束外延技术在蓝宝石衬底上外延了晶体质量较好的单晶InAlGaN薄膜．在生长InAlGaN外延层时，获得了外延膜的二维生长，卢瑟福背散射测量结果表明，InAlGaN外延层中In，Al和Ga的组分分别为2％，22％和76％，并且元素的深度分布比较均匀，InAlGaN（0002）三晶X射线衍射摇摆曲线的半高宽为4．8′，通过原子力显微镜观察外延膜表面存在小山丘状的突起和一些小坑，测量得到外延膜表面的均方根粗糙度为2．2nm．利用光电导谱测量InAlGaN的带隙为3．76eV．

Monolithically Integrated Optoelectronic Receivers Implemented in 0. 25μm MS/RF CMOS

A monolithically integrated optoelectronic receiver is presented. A silicon-based photo-diode and receiver circuits are integrated on identical substrates in order to eliminate the parasitics induced by hybrid packaging. Implemented in the present deep sub-micron MS/RF （mixed signal, radio frequency） CMOS,this monolithically OEIC takes advantage of several new features to improve the performance of the photo-diode and eventually the whole OEIC.

MS／RF CMOS工艺兼容的光电探测器

为实现光纤通信系统中的单片光电集成，采用工业标准工艺设计了硅基光电探测器，讨论了光电探测器的机理，提出了五种新的探测器结构，并采用TSMC0．18μmMS／RF CMOS工艺进行了流片．利用半导体测试仪对芯片进行了测试，包括探测器的暗电流、响应度和结电容，并分析了深n阱、浅沟槽隔离等工艺步骤对探测器参数的影响．结果表明，利用标准MS／RF CMOS工艺实现的光电探测器具有良好的特性。

蓝宝石衬底上单晶InN外延膜的RF-MBE生长

采用低温氮化铟(InN)缓冲层，利用射频等离子体辅助分子束外延(RF-MBE)方法在蓝宝石衬底上获得了晶体质量较好的单晶InN外延膜．用光学显微镜观察所外延的InN单晶薄膜，表面无铟滴．InN(0002)双晶X射线衍射摇摆曲线的半高宽为14′；用原子力显微镜测得的表面平均粗糙度为3．3nm；Hall测量表明InN外延膜的室温背景电子浓度为3．3×10^18cm^3，相应的电子迁移率为262cm^2／(V·s)．

RF-MBE Grown AlGaN/GaN HEMT Structure with High Al Content

A Si doped AlGaN/GaN HEMT structure with high Al content (x= 44%) in the barrier layer is grown on sapphire substrate by RF-MBE. The structural and electrical properties of the heterostructure are investigated by the triple axis X-ray diffraction and Van der Pauw-Hall measurement, respectively. The observed prominent Bragg peaks of the GaN and AlGaN and the Hall results show that the structure is of high quality with smooth interface.fabricated and characterized. Better DC characteristics, maximum drain current of 1.0A/mm and extrinsic transconductance of 218mS/mm are obtained when compared with HEMTs fabricated using structures with lower Al mole fraction in the AlGaN barrier layer. The results suggest that the high Al content in the AlGaN barrier layer is promising in improving material electrical properties and device performance.

RF-MBE生长AlN/GaN超晶格结构二维电子气材料

用射频等离子体辅助分子束外延技术（RF-MBE）在c面蓝宝石衬底上外延了高质量的GaN膜以及AlN/GaN超晶格结构极化感应二维电子气材料。所获得的掺Si的GaN膜室温电子浓度为2.2 * 10~(18)cm~(-3)，相应的电子迁移率为221cm~2/(V·s);1μm厚的GaN外延膜的（0002）X射线衍射摇摆曲线半高宽（FWHM）为7’；极化感应产生的二维电子气室温电子迁移率达到1086cm~2/(V·s)，相应的二维电子气面密度为7.5 * 10~(12)cm~(-2)。

RF-MBE生长AlGaN/GaN二维电子气材料

于2010-11-23批量导入