discussed relevant factors in accommodating the mismatch in the SiGe system, pointing out the great dominance of the market that silicon will retain for the foreseeable future. of An experimental paper on MBE Si-Ge growth was presented by T. Sakamoto Electrotechnical Laboratory. His group demonstrated the great power of observation of growth in-situ by oscillatory RHEED measurements. They reported that Ge-Si layers tend to grow in a three-dimensional way, resulting in a decrease of oscillation intensity of the RHEED, which was more rapid for higher Ge content. Oscillation intensity recovered, however, for subsequent growth of Si layers. There are still problems to be unravelled for this important system. A. Ishibashi of Sony Research Center reported studies of (AlAs)m(GaAs)n ultrathin superlattices (UTSL), where m and n ranged from 1 to 25 and layer thicknesses were about 400 nm. The materials were grown by MOCVD but shown to be of monolayer abruptness. Using Raman scattering and photoluminescence, they investigated the dimensionality of the electrons, and of the phonons, and arrived at the conclusion that as the layer thickness increased, phonons were twodimensional until around 5 nm, after which they transitioned to three dimensions, while electrons, starting off three-dimensional, dropped to two dimensions just as the phonons were going the other way. Electrons returned to three dimensions at around 50 nm. The authors speculated on the possible changes in electron-phonon interactions in such systems. 1/4 Tm < T < 1/2 Tm Two-dimensional epitaxy 1/2 Tm < T < 3/4 Tm Strip flow epitaxy 3/4 Tm <T Three-dimensional epitaxy Furthermore, by considering published data on other systems, such as Si/Si, GeSi/Si, GaAs/GaAs, GaAlAs/GaAs, and InP/InP, he concluded that these regions represented a universal scaling of growth mode to melting temperature, an interesting guideline to choosing substrate temperature when starting the study of a new system As stated in the beginning, the workshop represented a good summation of current work in the field and provided a vehicle for discussion among workers in the field of current issues. It is my impression that Japanese participation in discussions at English language meetings is becoming stronger than in the past. George B. Wright, director of ONR/AFOSR/ARO Far East from August 1985, has been program director of solid state physics and physical electronics at ONR since 1978. He was previously Batchelor Professor of Electrical Engineering and Professor of Physics at Stevens Institute of Technology. His research interests include the relation between electronic structure and properties of solids and microscopics of materials processing for electronic devices. Dr. Wright is a Fellow of the American Physical Society and a member of the IEEE. II-1 II-2 II-3 II-4 Fine Epitaxy: Present State-of-the-Art in Fine Epitaxy: How good is it and Vacuum Epitaxy of Semiconductors Using Nonelemental Sources Digital Epitaxy Akira Usui, NEC Corporation Switching Laser--MOVPE Yoshinobu Aoyagi, Atsutoshi Doi, Souhachi Iwai, and Susumu Namba, II-5 Migration Enhanced Epitaxy Yoshiji Horikoshi, Nippon Telegraph and Telephone Company (NTT) RESONANT TUNNELING DEVICES III-1 III-2 III-3 III-4 III-5 III-6 Physics of Resonant Tunneling Devices Serge Luryi, AT&T Bell Laboratories Resonant Transport in AlGaAs-GaAs-AlGaAs Double Barrier Structures Triple Barrier Resonant Tunneling Devices T. Nakagawa, T. Kojima, and K. Ohta, Electrotechnical Laboratory S. Muto, T. Inata, Y. Sugiyama, Y. Nakata, and S. Hiyamizu, Fujitsu Ltd. Y. Ando, H. Toyoshima, A. Okamoto, and T. Itoh, NEC Corporation Microwave and Millimeter-Wave Resonant Tunneling Diodes III-7 Resonant Tunneling Transistors N. Yokoyama, T. Mori, T. Futatsugi, S. Muto, T. Ohnishi, and HET AND BALLISTIC TRANSPORT IV-1 IV-2 IV-3 Ballistic Transport and Energy Spectroscopy of Hot Electrons in THETA M. Heiblum, IBM Corporation Hot Electron Transistors (HETs) Using InGaAs/InAlGaAs Heterostructures Intervalley Scattering Observed in an AlGaAs/GaAs Hot Electron Transistor HIGH ELECTRON MOBILITY TRANSISTORS (HEMT) AND V-1 V-2 V-3 V-4 V-5 Device Physics and New Developments in Heterostructure FETs Recent Advances in HEMT LSI Technology Comments on Heterojunction FETs Fumio Hasegawa, Tsukuba University Monte Carlo Particle Simulation of Heterojunction FET & HBT HBT Tadao Ishibashi, Nippon Telegraph and Telephone Corporation NEW HETEROSTRUCTURE MATERIALS VI-1 VI-2 VI-3 MBE Growth of Strained-Layer Superlattice Device Structures InAs/GaAs Strained Layer Superlattice Y. Matsui, H. Hayashi, K. Ono, and K. Yoshida, Research and Atomic Layer Superlattice A. Ishibashi, Y. Mori, M. Itabashi, and M. Watanabe, Sony Corporation VI-6 E. Kasper, AEG Research Center ULM, FRG SiGe/Si Fine Epitaxy T. Sakamoto and K. Sakamoto, Electrotechnical Laboratory; S. Nagao, Growth Modes in the Heteroepitaxy of NiSi2 Layers on Si Akitoshi Ishizaka, Central Research Laboratories Hitachi Ltd. THE INTERNATIONAL CONFERENCE ON PLASMA SCIENCE AND TECHNOLOGY, BEIJING, CHINA A.K. Hyder and M. Kristiansen The International Conference on Plasma Science and Technology was the first effort by the Chinese community to host an international conference on plasma science. The invited papers from foreign scientists featured technology rather than science and were more in the vein of reviews rather than innovation. The authors describe the contributed Chinese work and offer comments on present Chinese difficulties with basic research in this technical area. INTRODUCTION and The International Conference on Plasma Science and Technology, held in Beijing, the People's Republic of China, in June 1986, was sponsored by the Chinese Society of Theoretical and Applied Mechanics and the Beijing Society of Plasma Science Technology. About 120 papers were presented by authors from 14 different countries during the 4-day conference. Seven invited talks were given. Well over half of the papers were by authors from China, SO this article will concentrate on work reported by the host country scientists. This was the first effort by the Chinese community to host an international conference in plasma science, and the effort resulted in mixed success. It was an adequate first effort and will certainly provide the basis for future meetings. There were two primary deficiencies noted: there were no significant first-report papers presented, and the attendance by non-Chinese participants did not include a meaningful number of leaders from the plasma science and technology community outside of China. This was in spite of the attempt to attract foreign participation by scheduling the meeting in tandem with the BEAMS '86 Conference in Kobe, Japan. In retrospect, the primary causes of the limited success of the conference may have been the selection of of some nonactive scientists for the Steering Committee, as reflected in the quality and timeliness of the invited papers, and the lack of any significant announcement of the meeting in Western countries. In all, the conference should be viewed for what it was--an initial attempt by a fledgling Chinese plasma science community to introduce itself to the Western community and to introduce that Western community to China. The next International Conference on Plasma Science and Technology will, most certainly, be greatly improved. SUMMARY OF THE INVITED PAPERS The invited papers were generally not in keeping with the great attention to detail that characterized the conference overall. The opening talk by J. Kistemaker of the Netherlands was an introductory tutorial on plasma science. The second basic theory talk, given by Professor Pfender of the University of Minnesota, was a good review of heat transfer in plasma flows; unfortunately, the paper does not appear in the Proceedings even though Pfender is a member of the Steering Committee. The four remaining invited talks concerned plasma technology rather than plasma science: |