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31 results on '"Shao, Tianhao"'

1. Single crystal synthesis and low-lying electronic structure of V$_3$S$_4$

Author

Hao, Yu-Jie, Zhu, Ming-Yuan, Ma, Xiao-Ming, Zhang, Chengcheng, Rong, Hongtao, Jiang, Qi, Yang, Yichen, Jiang, Zhicheng, Liu, Xiang-Rui, Zhu, Yupeng, Zeng, Meng, Lu, Ruie, Shao, Tianhao, Liu, Xin, Xu, Hu, Liu, Zhengtai, Ye, Mao, Shen, Dawei, Chen, Chaoyu, and Liu, Chang

Subjects
Condensed Matter - Materials Science
Abstract

We report successful growth of millimeter-sized high quality single crystals of V$_3$S$_4$, a candidate topological semimetal belonging to a low-symmetry space group and consisting of only low atomic number elements. Using density functional theory calculations and angle-resolved photoemission spectroscopy, we show that the nonmagnetic phase of monoclinic V$_3$S$_4$ hosts type-II Dirac-like quasiparticles which opens a sizable gap due to spin orbit coupling, as well as theoretical multiple nodal lines that are eliminated also by spin orbit coupling. These results suggest that relativistic effects give rise to profound modifications of the topological properties even in compounds with low-weight elements., Comment: 19 Pages, 3 Figures. To be published in Journal of Alloys and Compounds

Published
2022

2. Production of light antinuclei in $pp$ collisions by dynamical coalescence and their fluxes in cosmic rays near earth

Author

Shao, Tianhao, Chen, Jinhui, Ma, Yu-Gang, and Xu, Zhangbu

Subjects
High Energy Physics - Phenomenology, Nuclear Experiment
Abstract

Light antinucleus yields are calculated in a multiphase transport model (AMPT) coupled with a dynamical coalescence model. The model is tuned to reproduce the transverse momentum and rapidity distributions of antiproton in $pp$ collisions at $\rm \sqrt{s}$ = 7.7 GeV to 7 TeV. By applying a widely used cosmic ray propagation model, the antinucleus fluxes near the earth are estimated over a broad range of kinetic energies. Our result on the antideuteron flux is consistent with the calculations in the literature, while our upper limit on the antihelium-3 flux sits in-between calculations in the field that span an order of magnitude in its value. This study suggests that further accurate estimation of secondary antihelium-3 flux could be improved with more ground-based experiments and model simulations. Most importantly, our value of antinucleus background from hadronic source is far below the projected sensitivity of AMS-02 with 5 years of integration time, which supports the idea of searching for new physics by measurements of light antinuclei in upcoming decade., Comment: 8 pages, 9 figures, submitted for publication

Published
2022
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4. Enhanced production of strange baryons in high energy nuclear collisions from a multiphase transport model

Author

Shao, Tianhao, Chen, Jinhui, Ko, Che Ming, and Lin, Zi-Wei

Subjects
Nuclear Theory, Nuclear Experiment
Abstract

We introduce additional coalescence factors for the production of strange baryons in a multiphase transport (AMPT) model in order to describe the enhanced production of multistrange hadrons observed in Pb-Pb collisions at $\rm \sqrt{s_{NN}}$ = 2.76 TeV at the Large hadron Collider (LHC) and Au+Au collisions at $\rm \sqrt{s_{NN}}$ = 200 GeV at Relativistic Heavy-Ion Collider (RHIC).This extended AMPT model is found to also give a reasonable description of the multiplicity dependence of the strangeness enhancement observed in high multiplicity events in $pp$ collisions at $\rm \sqrt{s}$ = 7 TeV and $p$-Pb collisions at $\rm \sqrt{s_{NN}}$ = 5.02 TeV. We find that the coalescence factors depend on the system size but not much on whether the system is produced from A+A or p+A collisions. The extended AMPT model thus provides a convenient way to model the mechanism underlying the observed strangeness enhancement in collisions of both small and large systems at RHIC and LHC energies., Comment: 15 pages, 5 figures

Published
2020
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5. Yield ratio of hypertriton to light nuclei in heavy-ion collisions from $\rm \sqrt{s_{NN}}$ = 4.9 GeV to 2.76 TeV

Author

Shao, Tianhao, Chen, Jinhui, Ko, Che Ming, Sun, Kai-Jia, and Xu, Zhangbu

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

We resolve the difference in the yield ratio $\rm S_3$ = $\rm \frac{N_{^3_{\Lambda}H}/N_\Lambda}{N_{^3He}/N_p}$ measured in Au+Au collisions at $\rm \sqrt{s_{NN}}$ = 200 GeV and in Pb-Pb collisions at $\rm \sqrt{s_{NN}}$ = 2.76 TeV by adopting a different treatment of the weak decay contribution to the proton yield in Au+Au collisions at $\rm \sqrt{s_{NN}}$ = 200 GeV. We then use the coalescence model to extract information on the $\Lambda$ and nucleon density fluctuations at the kinetic freeze-out of heavy ion collisions. We also show from available experimental data that the yield ratio $\rm S_2$ = $\rm \frac{N_{^3_{\Lambda}H}}{N_\Lambda N_ d}$ is a more promising observable than $\rm S_3$ for probing the local baryon-strangeness correlation in the produced medium., Comment: 15 pages, 2 figures, 3 tables, submitted for publication

Published
2020
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6. Probing QCD critical fluctuations from the yield ratio of strange hadrons in relativistic heavy-ion collisions

Author

Shao, Tianhao, Chen, Jinhui, Ko, Che Ming, and Sun, Kai-Jia

Subjects
High Energy Physics - Phenomenology, Nuclear Experiment, Nuclear Theory
Abstract

By analyzing the available data on strange hadrons in central Pb+Pb collisions from the NA49 Collaboration at the Super Proton Synchrotron (SPS) and in central Au+Au collisions from the STAR Collaboration at the Relativistic Heavy-Ion Collider (RHIC) in a wide collision energy range from $\sqrt{s_{\rm NN}}$ = 6.3 GeV to 200 GeV, we find a possible non-monotonic behavior in the ratio $\mathcal{O}_\text{K-$\Xi$-$\phi$-$\Lambda$}$= $\frac{N(K^+)N(\Xi^-)}{N(\phi)N(\Lambda)}$ of $K^+$, $\Xi^-$, $\phi$, and $\Lambda$ yields as a function of $\sqrt{s_{\rm NN}}$. Based on the quark coalescence model, which can take into account the effect of quark density fluctuations on hadron production, a possible non-monotonic behavior in the dependence of the strange quark density fluctuation on $\sqrt{s_{NN}}$ is obtained. This is in contrast to the coalescence model that does not include quark density fluctuations and also to the statistical hadronization model as both fail to describe even qualitatively the collision energy dependence of the ratio $\mathcal{O}_\text{K-$\Xi$-$\phi$-$\Lambda$}$. Our findings thus suggest that the signal and location of a possible critical endpoint in the QCD phase diagram, which is expected to result in large quark density fluctuations, can be found in the on-going Bean Energy Scan program at RHIC., Comment: 7 pages, 3 tables and 1 figure

Published
2019
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15. Commissioning of the hypertriton binding energy measurement at MAMI

Author

Eckert Philipp, Achenbach Patrick, Akiyama Takeru, Chen Jinhui, Distler Michael O., Esser Anselm, Geratz Julian, Helmel Christian, Hoek Michael, Itabashi Kosuke, Kaneta Masashi, Kino Ryoko, Klag Pascal, Ma Yu-Gang, Merkel Harald, Mizuno Masaya, Müller Ulrich, Nagao Sho, Nakamura Satoshi N., Nakamura Yuki R., Okuyama Kazuki, Pochodzalla Josef, Schlimme Björn Sören, Sfienti Concettina, Shao Tianhao, Steinen Marcell, Tachibana Koga, Thiel Michaela, Toyama Yuichi, and Uehara Keita

Subjects
Physics, QC1-999
Abstract

A high-precision hypernuclear experiment has been commissioned at the Mainz Microtron (MAMI) to determine the hypertriton Λ binding energy via decay-pion spectroscopy. The method has been successfully pioneered with 4ΛH studies in the last decade. The experiment makes use of a novel high luminosity lithium target with a length of 45mm while being only 0.75mm thick to keep momentum smearing of the decay pions low. The target-to-beam alignment as well as the observation of the deposited heat is achieved with a newly developed thermal imaging system. Together with a precise beam energy determination via the undulator light interference method a recalibration of the magnetic spectrometers will be done to obtain a statistical and systematic error of about 20 keV. The experiment started in the summer of 2022 and initial optimization studies for luminosity and data quality are presented.

Published
2022
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16. Study of charge symmetry breaking in A = 4 hypernuclei in √sNN = 3 GeV Au+Au collisions at RHIC

Author

Shao Tianhao

Subjects
Physics, QC1-999
Abstract

In these proceedings, we present the measurement of the charge symmetry breaking in A = 4 hypernuclei in Au+Au collisions at √sNN = 3 GeV. The signal reconstruction and binding energy measurements of 4ΛH and 4ΛHe, including corrections on momentum, are discussed. Our result of Λ binding energy difference for ground states is ΔBΛ(0+) = 0.16 ± 0.14(stat.) ± 0.10(syst.) MeV. Combined with the energy levels of excited states, the difference for excited states is ΔBΛ(1+) = −0.16 ± 0.14(stat.) ± 0.10(syst.) MeV which shows a negative sign with a magnitude comparable to the result of ground states. These results are compared with previous measurements and theoretical model calculations.

Published
2022
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20. Study of charge symmetry breaking in A = 4 hypernuclei in √sNN = 3 GeV Au+Au collisions at RHIC.

Author

Shao, Tianhao

Subjects
*SYMMETRY breaking, *HYPERFRAGMENTS, *HEAVY ion collisions, *BINDING energy, *GROUND state energy
Abstract

In these proceedings, we present the measurement of the charge symmetry breaking in A = 4 hypernuclei in Au+Au collisions at √sNN = 3 GeV. The signal reconstruction and binding energy measurements of 4ΛH and 4ΛHe, including corrections on momentum, are discussed. Our result of Λ binding energy difference for ground states is ΔBΛ(0+) = 0.16 ± 0.14(stat.) ± 0.10(syst.) MeV. Combined with the energy levels of excited states, the difference for excited states is ΔBΛ(1+) = −0.16 ± 0.14(stat.) ± 0.10(syst.) MeV which shows a negative sign with a magnitude comparable to the result of ground states. These results are compared with previous measurements and theoretical model calculations. [ABSTRACT FROM AUTHOR]

Published
2022
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21. Probing the Gluonic Structure of the Deuteron with J/ψ Photoproduction in d+Au Ultraperipheral Collisions

Author

Abdallah, Mohamed, Aboona, Bassam, Adam, Jaroslav, Adamczyk, Leszek, Adams, Joseph, Adkins, Kevin, Agakishiev, Geydar, Aggarwal, Ishu, Aggarwal, Madan, Ahammed, Zubayer, Aitbaev, A., Alekseev, Igor, Anderson, Derek, Aparin, Alexey, Aschenauer, Elke-Caroline, Ashraf, Muhammad Usman, Atetalla, Fareha, Attri, Anjali, Averichev, Georgy, Bairathi, Vipul, Baker, William, Ball Cap, Jonathan Gonzalo, Barish, Kenneth, Behera, Arabinda, Bellwied, Rene, Bhagat, Pratibha, Bhasin, Anju, Bielcik, Jaroslav, Bielcikova, Jana, Bordyuzhin, Igor, Brandenburg, James, Brandin, Andrei, Bunzarov, Ivan, Cai, Xiang-Zhou, Caines, Helen, Calderon de la Barca Sanchez, Manuel, Cebra, Daniel, Chakaberia, Irakli, Chaloupka, Petr, Chan, Brian, Chang, Feng-Han, Chang, Zilong, Chankova-Bunzarova, Nedialka, Chatterjee, Arghya, Chattopadhyay, Subhasis, Chen, Ding, Chen, Jia, Chen, Jinhui, Chen, Xiaolong, Chen, Zhenyu, Cheng, Jianping, Chevalier, Malia, Choudhury, Subikash, Christie, W., Christie, Bill, Chu, Xiaoxuan, Crawford, Hank, Csanad, Mate, Daugherity, Michael, Dedovich, Tatiana, Deppner, Ingo, Derevschikov, Anatoly, Dhamija, Arushi, Di Carlo, Launa, Didenko, Lidia, Dixit, Prabhupada, Dong, Xin, Drachenberg, James, Duckworth, Eddie, Dunlop, James, Elsey, Nicholas, Engelage, Jack, Eppley, Geary, Esumi, ShinIchi, Evdokimov, Olga, Ewigleben, Annika, Eyser, Oleg, Fatemi, Renee, Fawzi, Fares, Fazio, Salvatore, Federic, Pavol, Fedorisin, Jan, Feng, Chan-Jui, Feng, Yicheng, Filip, Peter, Finch, Evan, Fisyak, Yuri, Francisco, Audrey, Fu, Chuan, Fulek, Lukasz, Gagliardi, Carl, Galatyuk, Tatyana, Geurts, Frank, Ghimire, Navagyan, Gibson, Adam, Gopal, Krishan, Gou, Xingrui, Grosnick, David, Gupta, Anik, Guryn, Wlodek, Hamad, Ayman, Hamed, Ahmed, Han, Yiding, Harabasz, Szymon, Harasty, Matthew, Harris, John, Harrison, Hannah, He, Shu, He, Wanbing, He, Xionghong, He, Yang, Heppelmann, Samuel, Heppelmann, Steven, Herrmann, Norbert, Hoffman, Eric, Holub, Lukas, Hu, C., Hu, Q., Hu, Yu, Huang, Hao, Huang, Huan, Huang, Shengli, Huang, Te-Chuan, Huang, Xinjie, Huang, Yan, Humanic, T.J., Igo, George, Isenhower, Donald, Isshiki, M., Jacobs, William, Jena, Chitrasen, Jentsch, Alexander, Ji, Yuanjing, Jia, Jiangyong, Jiang, Kun, Ju, Xinyue, Judd, Eleanor, Kabana, Sonia, Kabir, Md Latiful, Kagamaster, Skipper, Kalinkin, Dmitry, Kang, Kejun, Kapukchyan, David, Kauder, Kolja, Ke, Hongwei, Keane, Declan, Kechechyan, Armen, Kelsey, Matthew, Khyzhniak, Yevheniia, Kikola, Daniel, Kim, Chong, Kimelman, Benjamin, Kincses, Daniel, Kisel, Ivan, Kiselev, Alexander, Knospe, Anders, Ko, Ho San, Kochenda, Leonid, Korobitsin, A., Kosarzewski, Leszek, Kramarik, Lukas, Kravtsov, Petr, Kumar, Lokesh, Kumar, Shyam, Kunnawalkam Elayavalli, Raghav, Kwasizur, Joseph, Lacey, Roy, Lan, Shaowei, Landgraf, Jeffery, Lauret, Jerome, Lebedev, Alexei, Lednicky, Richard, Lee, Jeong-Hun, Leung, Yue-Hang, Lewis, Nicole, Li, Changfeng, Li, Cheng, Li, Wei, Li, Xin, Li, Yuanjing, Liang, Xilin, Liang, Yue, Licenik, Robert, Lin, Ting, Lin, Yufu, Lisa, Mike, Liu, Feng, Liu, Huanzhao, Liu, Hui, Liu, Peifeng, Liu, Tong, Liu, Xiaoyu, Liu, Yanfang, Liu, Zhen, Ljubicic, Tonko, Llope, W.J., Longacre, R.S., Loyd, Erik, Lu, T., Lukow, Nicholas, Luo, Xiaofeng, Ma, Long, Ma, Rongrong, Ma, Yu-Gang, Magdy Abdelwahab Abdelrahman, Niseem, Mallick, Debasish, Manukhov, S.L., Margetis, Spiros, Markert, Christina, Matis, Howard, Mazer, Joel, Minaev, Nikolai, Mioduszewski, Saskia, Mohanty, Bedanga, Mondal, Mriganka, Mooney, Isaac, Morozov, Dmitry, Mukherjee, Ayon, Nagy, Marton, Nam, J.D., Nasim, Md., Nayak, Kishora, Neff, Dylan, Nelson, John, Nemes, Daniel, Nie, Maowu, Nigmatkulov, Grigory, Niida, Takafumi, Nishitani, Risa, Nogach, Larisa, Nonaka, Toshihiro, Nunes, Ana Sofia, Odyniec, Grazyna, Ogawa, Akio, Oh, Saehanseul, Okorokov, Vitalii, Okubo, K., Page, Brian, Pak, Robert, Pan, Jinjin, Pandav, Ashish, Pandey, Ashutosh, Panebratsev, Yuri, Parfenov, Petr, Pinsky, Lawrence, Paul, A., Pawlik, Bogdan, Pawlowska, Diana, Perkins, Chris, Pluta, Jan, Pokhrel, Babu, Ponimatkin, Georgij, Porter, Jeff, Posik, Matthew, Prozorova, Veronika, Pruthi, Navneet Kumar, Przybycien, Mariusz, Putschke, Joern, Qiu, Hao, Quintero, Amilkar, Racz, Cameron, Radhakrishnan, Sooraj, Raha, Nandita, Ray, Lanny, Reed, Rosi, Ritter, Hans Georg, Robotkova, Monika, Rogachevskiy, Oleg, Romero, Juan, Roy, Diptanil, Ruan, Lijuan, Rusnak, Jan, Sahoo, Aswini, Sahoo, Nihar, Sako, Hiroyuki, Salur, Sevil, Samigullin, E., Sandweiss, Jack, Sato, Susumu, Schmidke, Bill, Schmitz, Norbert, Schweid, Benjamin, Seck, Florian, Seger, Janet, Sergeeva, Maria, Seto, Richard, Seyboth, Peter, Shah, Neha, Shahaliev, Ehtiram, Shanmuganathan, Prashanth, Shao, Ming, Shao, Tianhao, Sharma, R., Sheikh, Ashik Ikbal, Shen, Diyu, Shi, Shusu, Shi, Yingying, Shou, Qi-Ye, Sichtermann, Ernst, Sikora, Rafal, Simko, Miroslav, Singh, Jagbir, Singha, Subhash, Sorensen, Paul, Sinha, P., Skoby, Michael, Smirnov, Nikolai, Soehngen, Yannick, Solyst, William, Song, Youqi, Spinka, H.M., Srivastava, Brijesh, Stanislaus, Shirvel, Stefaniak, Maria, Stewart, David, Strikhanov, Mikhail, Stringfellow, Blair, Suaide, Alexandre Alarcon, Sumbera, Michal, Summa, Branden, Sun, Xiangming, Sun, Xu, Sun, Yongjie, Sun, Yuliang, Surrow, Bernd, Svirida, Dmitry, Sweger, Zachary, Szymanski, Pawel, Tang, Aihong, Tang, Zebo, Taranenko, Arkadiy, Tarnowsky, Terry, Thomas, J.H., Timmins, Anthony, Tlusty, David, Todoroki, Takahito, Tokarev, Michael, Tomkiel, Catherine, Trentalange, Steven, Tribble, Robert, Tribedy, Prithwish, Tripathy, Srikanta Kumar, Truhlar, Tomas, Trzeciak, Barbara, Tsai, Oleg, Tu, Zhoudunming (Kong), Ullrich, Thomas, Underwood, Dave, Upsal, Isaac, Van Buren, Gene, Vanek, Jan, Vasiliev, Alexander, Vassiliev, Iouri, Verkest, Veronica, Videbaek, Flemming, Vokal, Stanislav, Voloshin, Sergei, Wang, Fuqiang, Wang, Gang, Wang, Jiansong, Wang, Pengfei, Wang, Xiaofeng, Wang, Yaping, Wang, Yi, Wang, Zhen, Webb, Jason, Weidenkaff, Philipp, Wen, Liwen, Westfall, Gary, Wieman, Howard, Wissink, Scott, Witt, Richard, Wu, Jin, Wu, Junlin, Wu, Yang, Xi, Baoshan, Xiao, Zhigang, Xie, Guannan, Xie, Wei, Xu, Haojie, Xu, Nu, Xu, Qinghua, Xu, Yike, Xu, Zhangbu, Xu, Zhiwan, Yan, Gaoguo, Yang, Chi, Yang, Qian, Yang, Shuai, Yang, Yi, Ye, Zaochen, Ye, Zhenyu, Yi, Li, Yip, Kin, Yu, Yi, Zbroszczyk, Hanna, Zha, Wangmei, Zhang, ChunJian, Zhang, Dingwei, Zhang, Jinlong, Zhang, Xiaoping, Zhao, F., Zhang, Shenghui, Zhang, Song, Zhang, Yapeng, Zhang, Yifei, Zhang, Yu, Zhang, Zhe-Jia, Zhang, Zhengqiao, Zhang, Ziyue, Zhao, Jie, Zhao, M., Zhou, Chensheng, Zhou, Yingjie, Zhu, Xianglei, Zurek, Maria, and Zyzak, Maksym

Subjects
Nuclear Theory, nucl-th, hep-ex, FOS: Physical sciences, nucl-ex, High Energy Physics - Experiment, Nuclear Theory (nucl-th), High Energy Physics - Experiment (hep-ex), Nuclear Physics - Theory, High Energy Physics::Experiment, Nuclear Physics - Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, Particle Physics - Experiment
Abstract

Understanding gluon density distributions and how they are modified in nuclei are among the most important goals in nuclear physics. In recent years, diffractive vector meson production measured in ultra-peripheral collisions (UPCs) at heavy-ion colliders has provided a new tool for probing the gluon density. In this Letter, we report the first measurement of $J/\psi$ photoproduction off the deuteron in UPCs at the center-of-mass energy $\sqrt{s_{_{\rm NN}}}=200~\rm GeV$ in d$+$Au collisions. The differential cross section as a function of momentum transfer $-t$ is measured. In addition, data with a neutron tagged in the deuteron-going Zero-Degree Calorimeter is investigated for the first time, which is found to be consistent with the expectation of incoherent diffractive scattering at low momentum transfer. Theoretical predictions based on the Color Glass Condensate saturation model and the gluon shadowing model are compared with the data quantitatively. A better agreement with the saturation model has been observed. With the current measurement, the results are found to be directly sensitive to the gluon density distribution of the deuteron and the deuteron breakup, which provides insights into the nuclear gluonic structure., Comment: Final published version Phys. Rev. Lett. 128, 122303

Published
2021

25. Review of replanning in hierarchical task network.

Author

SHAO Tianhao, ZHANG Hongjun, CHENG Kai, DAI Chengyou, YU Xiaohan, and ZHANG Ke

Subjects
HIERARCHICAL Bayes model, ELEVATING platforms, EMERGENCY management, TASKS
Abstract

As an important part of the intelligent planning technology, hierarchical task network (HTN) is successfully applied to the task planning in unmanned aerial vehicle platform, emergency plan formulation and other fields. Due to effect the increasing uncertain factors on the implementation the influence of the plan, it is urgent to use replanning technology, thus the replanning technology based on HTN has become a hotspot in recent years. First of all, a three-layer replan framework based on HTN is proposed by summarizing the current research status. Then, the corresponding technical route and implementation details are represented from three levels of plan repair, local replanning and global replanning in the framework respectively, and the advantages and disadvantages of the current method are pointed out for different levels. Finally, the future research direction of this problem is prospected, and the key problems to be solved and the solutions are putting forward. [ABSTRACT FROM AUTHOR]

Published
2020
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26. Lattice disorder, refractive index changes and waveguides in LiNbO3 formed by H+-implantation

Author

Feng Xiqi, Shao Tianhao, Jiang Xinyuan, and Xu Zhengquan

Subjects
Fabrication, Materials science, business.industry, Annealing (metallurgy), Quantitative Biology::Tissues and Organs, Mechanical Engineering, Physics::Optics, Condensed Matter Physics, Ion, law.invention, Ion implantation, Optics, Planar, Mechanics of Materials, law, Radiation damage, General Materials Science, sense organs, business, Waveguide, Refractive index
Abstract

H + -implantation in LiNbO 3 induces radiation damage, lattice disorder and corresponding refractive index changes. The refractive index decreases in the nuclear stopping region at the end of the implanted ion's track, but changes very little in the electronic stopping region. Thus, these characteristics can be used for fabrication of planar waveguides. The waveguide fabrication process comprises a furnace annealing in flowing oxygen to remove the damage and optical absorption from the guiding layer as well as to compensate oxygen loss during ion implantation. The damaged buried layer together with electronic excitement forms an optical “well”, which confines optical mode propagation. The results of this work show that H + -implantation can be a promising technique for fabrication of low-loss waveguides.

Published
1993

27. Effects of ion implantation on surface composition and enhanced etching in LiNbO3

Author

Shang Wei, Jiang Xinyuan, Shao Tianhao, and Feng Xiqi

Subjects
Auger electron spectroscopy, Materials science, Mechanical Engineering, Diffusion, Analytical chemistry, Condensed Matter Physics, Channelling, Decomposition, Ion, Ion implantation, Mechanics of Materials, Etching (microfabrication), Radiation damage, General Materials Science
Abstract

Implantations of Xe+, Ar+ and N+ ions at room temperature cause radiation damage, volume expansion and near-surface decomposition in LiNbO3. Precipitates of Li2O are formed in surface regions when exposed to the atmosphere. Amorphization induced by heavy damage is observed in the ion-implanted region, which enhances the etching rate of LiNbO3. These effects were investigated using Rutherford back-scattering and channelling, Auger electron spectroscopy and secondary ion mass spectroscopy measurements, and some mechanisms for their occurrence are proposed and discussed.

Published
1991

28. The application of a 600 keV heavy ion implanter

Author

Jiang Xinyuan, Zhao Qihua, Lin Chenglu, Guan Anmin, and Shao Tianhao

Subjects
Nuclear and High Energy Physics, Materials science, Silicon, Polyatomic ion, Analytical chemistry, chemistry.chemical_element, Threshold voltage, Ion implantation, CMOS, chemistry, Getter, Graphite, Instrumentation, Layer (electronics)
Abstract

The application of a 600 keV heavy ion implanter is described. High energy B+ and high energy doubly charged P2+ were implanted in silicon for p- and n-wells isolation in CMOS ICs. 600 keV Ar+ was implanted in silicon to form a damage layer, the perfect layer near the surface of the Si-wafer was made by defect gettering- Si+ Mg+ and O+ were implanted in GaAs, and the uniformity of the threshold voltage (Vth) of GaAs MESFETs buried with Mg or O layers was improved. High activation efficiencies of Mg+ and Si+ implanted GaAs after RTA were obtained by using a specially designed graphite heater, and the activation efficiencies were 100% and 92%, respectively. The isolation of GaAs and InGaAsP/InP and other compound semiconductors, the characteristics of LiNbO3 and other insulators after high energy ion implantation and molecular ion implantation have also been investigated using this implanter.

Published
1991

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