Swelling or erosion on the surface of patterned GaN damaged by heavy ion implantation

Wurtzite undoped GaN epilayers (0 0 0 1) was implanted with 500 keV Au⁺ ions at room temperature under different doses, respectively. Ion implantation was performed through photoresist masks on GaN to produce alternating strips. The experimental results showed that the step height of swelling and decomposition in implanted GaN depended on ion dose and annealing temperature, i.e., damage level and its evolution. This damage evolution is contributed to implantation-induced defect production, and defect migration/accumulation occurred at different levels of displacement per atom. The results suggest that the swelling is due to the formation of porous structures in the amorphous region of implanted GaN. The decomposition of implanted area can be attributed to the disorder saturation and the diffusion of surface amorphous layer.     

大剂量P^＋离子注入单晶硅的研究

采用４８０ｋｅＶ Ｐ＾＋离子注入单晶硅，注入剂量为１×１０＾１６ｃｍ＾－２。采用ＲＢＳ、ＴＥＭ技术测试样品，发现样品经６００℃退火后，距样品表面约２４０ｎｍ处有一条低密度缺陷带。研究表明，这一现象与Ｐ＾＋的剂量及退火温度有关。     

Low energy implantation to inhibit wear in N+ ions implanted WC–Co composite

This work discusses the influence of nitrogen ion (N⁺) implantation on wear resistance of WC–Co composite. The WC–Co samples were bombarded at low N⁺ ions energies of 20 and 30 keV and doses of 10¹⁷ and 2 × 10¹⁷ ions cm⁻². Tribological tests were conducted against cylindrical 100Cr6 pin at 200 N load and 180 mm s⁻¹ speed. The tests use water lubrication and four sample types with Co binder content ranging in 6.5–25%. The X-ray spectra reveal that implantation is able to transform the original [CFC] Co structure of virgin surface to harder amorphous phase. However, it was found that excessive low binder content alters the wear behavior on non-implanted samples since it causes wear rate transition from 0.59 × 10⁻⁷ to 2.1 × 10⁻⁷ mm³/(mm² s) imposing hence instable wear regime. The SEM micrographs confirm the formation of transferred film within the implanted worn surface owing to (i) an enhancement in Co flow and (ii) a generation of oxides (Fe₂O₃, Fe₃O₄, Co₂O₃, WO₂). While the formed film acts to inhibit severe abrasion, the material removal process combining cobalt flow and carbide grains pull-out seems to be associated with oxidation mechanisms to be accentuated with energy increase. The most improvements in wear resistance were observed on samples with the highest Co content and the results were found more sensitive to N⁺ ions implantation energy than dose.     

Ferromagnetism in Co- and Mn-doped ZnO

Bulk single crystals of Sn-doped ZnO were implanted with Co or Mn at doses designed to produce transition metal concentrations of 3–5 at.% in the near-surface (2000 Å) region. The implantation was performed at 350 °C to promote dynamic annealing of ion-induced damage. Following annealing at 700 °C, temperature-dependent magnetization measurements showed ordering temperatures of 300 K for Co- and 250 K for Mn-implanted ZnO. Clear hysteresis loops were obtained at these temperatures. The coercive fields were 100 Oe for all measurement temperatures. X-ray diffraction showed no detectable second phases in the Mn-implanted material. One plausible origin for the ferromagnetism in this case is a carrier-induced mechanism. By sharp contrast, the Co-implanted material showed evidence for the presence of Co precipitates with hexagonal symmetry, which is the cause of the room temperature ferromagnetism. Our results are consistent with the stabilization of ferromagnetic states by electron doping in transition metal-doped ZnO predicted by Sato and Katayama–Yoshida [Jpn. J. Appl. Phys. 40 (2001) L334]. This work shows the excellent promise of Mn-doped ZnO for potential room temperature spintronic applications.     

Mn~+离子注入GaAs的铁磁性质和结构

报道 Mn+ 离子注入 ( 0 0 1 ) Ga As后经快速退火形成的亚微米铁磁晶粒的性质和结构特性 .磁化强度测量结果显示室温下具有铁磁性 .用透射电子显微镜、X射线能谱和电子衍射分析表明除形成 Mn Ga晶粒外 ,还有含少量 Ga的 Mn As晶粒 .原子力显微镜和磁力显微镜的结果表明在 750— 90 0℃下退火形成的铁磁颗粒以单畴为主     

Ion implantation of semi-insulating InP materials

Ｉｏｎｉｍｐｌａｎｔａｔｉｏｎｏｆｓｅｍｉ－ｉｎｓｕｌａｔｉｎｇＩｎＰｍａｔｅｒｉａｌｓＺＥＮＧＱｉｎｇｇａｏ（ＣｈｏｎｇｑｉｎｇＯｐｔｏｅｌｅｃｔｒｏｎｉｃｓＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅ，Ｙｏｎｇｃｈｕａｎ６３２１６３，ＣＨＮ）Ａｂｓｔｒａｃ...     

高温离子注入靶盘设计

简要介绍了高温离子注入靶室的设计。通过设计辅助加热装置使离子注入时晶片表面温度达到500℃以上,并通过靶盘旋转和往返平移扫描的方式实现了晶片片内和片间的温度均匀性,满足了碳化硅掺杂、SOI晶片制造等特殊需要。     

离子注入的特殊应用

描述了离子注入的几个特殊应用,其中包括离子束退火效应,增加肖特基势垒高度,注入吸杂效应,合成 SiO_2膜及离子注入材料改性等。     

MeV Si~+注入SI-GaAs的激活能研究

报导不同注量下MeV硅离子注入半绝缘砷化镓衬底的激活能,随注量增加激活能增大。对相同注入条件分别经一步或两步快退火处理样品的电特性进行了比较,认为MeV硅离子注入砷化镓衬底的退火行为可以分为损伤恢复和杂质激活两步,其杂质激活与点缺陷的运动有关。从能量角度分析了两步快退火优于一步快退火的原因。     

Ku波段高功率GaAs FET

报导Ｋｕ波段高功率ＧａＡｓＦＥＴ的制造技术，包括全离子注入、０．５μｍ自对准栅、高可靠欧姆接触、干法生长和刻蚀、背面通孔、内匹配和合成技术。器件由两个９．６ｍｍ栅宽的芯片组成，在１１．２～１１．７ＧＨｚ频带内，一分口增益压缩输出功率８Ｗ，增益６ｄＢ，功率附加效率２４％。