It is well recognized that high-speed and high-density silicon devices will be necessary for the ever-advancing information world in the 21 st century. However, it is not so clear, at this moment, what policy is required to enable the silicon industry to keep up with demands . This report discusses what subjects in silicon technology should be developed to meet the requirements in that age, emphasizing simulation technologies for the production of the high-quality silicon necessary for the advanced electronics industry. They will not only enable the production of top-quality wafers for various devices, but will also cut R & D costs and time. The strategy will require systematic simulation of fundamental research that has had a low level of activity until now. It should cover material properties at high temperature, such as the thermophysical properties of molten silicon. To solve the problem of human resources, scientists from various fields must be called together. R & D should be split among industry, government, and universities based on this strategy.

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At the beginning of this century, the main activities in Si crystal growth development are focused on the transition to the next larger diameter (300 mm) . As this transition entails huge investments in new fabs, -for silicon suppliers as well as device manufacturers-, a thorough cost analysis of the whole process sequence for wafer manufacturing is of utmost importance. In this respect, crystal growth receives special attention, as it is the most expensive and technologically most challenging process step in this sequence. While the complexity of the growth process increases with larger charge size and crystal diameter, the perfection of the growth process must significantly improve , as any disturbances that result in structure loss during growth cause massive material losses. The use of magnetic fields for the control of melt convection will probably become indispensable for a full scale production of 300 mm crystals. With regard to the future bulk quality, radical changes may be required as the design rule approaches the size of the prevailing grown-in crystal defect (vacancy aggregate) . One solution, which considerably reduces the defect size, is nitrogen doping in conjunction with a fast pull rate and, perhaps, an additional wafer heat treatment. Nitrogen doping also appears to be attractive for sufficient internal gettering capability in low thermal budget device processes due to the enhancement of oxygen precipitation. The other, more thorough approach is to grow defect free crystals, which, however, is a tedious task. It will be shown that neither the defect free crystal nor the high temperature treament approach are likely to meet the 300 mm cost of ownership expectations of the device industry, whereas epi wafers offer an economical compromise between high quality and price and, hence, will probably dominate the 300 mm era.

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Pure silicon wafers are free of COPs, oxidation induced stacking fault ring, and interstitial silicon dislocation loops. Pure silicon single crystal ingot can be grown with satisfying 0.213<V/G<0.219 mm^2 min^<-1>K^<-1> along radi-al and axial direction of crystal growth using CZ crystal growth method. Nitrogen doping during the crystal growth of pure silicon ingot changes vacancy-rich region to abnormal oxygen precipitate region via the reaction between interstitial nitrogen and vacancy. In addition, nitrogen doping does not change the pull rate margin of pure silicon ingot growth.

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We have developed the growth technology of grown-in defects free CZ silicon single crystals "Pure Silicon" and have produced them at the mass-production level since December, 1998. Pure Silicon is able to be grown by controlling axial and radial v/G in crystals where v is pulling rate, and G is the temperature gradient at the solid/liquid interface. Pure Silicon can improve dramatically performances and yield of devices because of free of grown-in defects such as COP, void defects, and nuclei of OISF which cause degradation of GOI, junction leakage, and isolation leakage. Pure Silicon is one of the most possible candidates for the future advanced devices even in the production of 12 inch wafers.

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Understanding and Controlling the nature of grown-in defects of Czochralski silicon crystals, especially octahedral void defects and oxygen precipitates, have been the key issue for silicon wafer industry to meet the drastic scaling down and integration of state of the art electronic devices in past three decades. We presented the nitrogen doping defect engineering which enables us to control both the voids and the oxygen precipitates simultaneously. By nitrogen doping, the morphology of the voids becomes plate shape triclinic and the size of the voids decreases, while the minute oxygen precipitates become already existent with high volume density in grown-in state crystals. Subsequent argon ambient annealing transforms the nitrogen doped wafers into ideal high performance wafers with stable defect free surface as well as subsurface zone for superior electric integrity and high density defect bulk region for strong impurity gettering ability. Implications for the mechanism of nitrogen effects are discussed.

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This report aims to forecast simulation technology in the coming century. The author discusses about the future condition of computer simulation from the point of view of basic science to actual application . Conditions of calculation using computers become extremely comfortable in the near future, therefore, we can obtain lots of results . The important points are as follows. 1) How to find meaningful results from lots of results. 2) How to predict attractive phenomena.

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Silicon melt surface plays a significant role as a drain for oxygen transport from the melt to space during crystal growth by the Czochralski method. Also at the melt surface Marangoni flow takes place. However, there has been no microscopic explanation on behavior of the melt surface. Marangoni convection visualization experiment under microgravity and precise measurement of surface tension and its temperature coefficient in an ambient atmosphere with various oxygen partial pressures show possibility that the silicon melt surface can be modified with adsorbed oxygen atoms or a thin oxide layer depending on oxygen partial pressure. Marangoni flow might be different between crystal growth by the Czochralski method with a SiO_2 Crucible and that by the floating zone method free from crucible. In order to obtain a microscopic understanding of the silicon melt surface, several novel techniques should be employed, so that a new technology to control oxygen behavior during crystal growth can be obtained.

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The recent development of LEC GaAs crystals has been reviewed, with paying attention on 150 mm large crystals. In order to meet the rapidly increasing demand for larger wafers used for microwave devices, crystals of 150 mm in diameter have been successfully developed and are now being produced industrially. The development of this larger wafer is based on technologies such as multi-zone heater furnace technology, three step annealing and polishing technologies.

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This update on crystal growth of bulk InP covers recent activities in the United States. A program combining theoretical modeling with experimental research and industrial manufacturing has culminated in the design and fabrication of a new generation crystal growth furnace. The new technology has the capability to produce large 100 mm diameter InP crystals by in-situ synthesis and growth. The dual functions of the new system are now being commercially exploited to supply future telecommunications needs in the US.

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This paper reviews the recent development of single crystal silicon carbide (SiC) bulk crystal growth. The technological potential of SiC for high-power, high-temperature and high-frequency electronic devices has been recognized for several decades; however, such applications have been largely hindered by problems related to bulk crystal growth. The SiC bulk crystal growth technology has recently achieved drastic improvement and enabled the growth of large high quality single crystals. Due to the availability of large high quality substrates, progress in SiC thin film epitaxy and devices has been rapid, and application of SiC to many fields is fast reaching its real potential.

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In the present paper, we discussed the importance of bulk GaN substrates for GaN based LEDs and LDs. For growing bulk GaN single crystals, we studied the pressure-controlled solution growth (PC-SG) method under " the Light for the 21st Century" Japanese national project. The recent results obtained by this method are presented. The maximum size of grown single crystals was 12 mm in diameter. It was shown that high quality GaN substrates, with low dislocation densities of the level of less than 2×10^5 cm^<-2> can be obtained.

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The market of compound semicondcutors is rapidly increasing but is based on III-V materials. For II-VI materials, many researches have been made not only in universities but also in industry, but were far from the real application. However, large progress has been made in industry, aiming at the real industrialization towards the 21 st century. Short comments have been contributed from these affliations so that readers can figure out the future of II-VI materials.

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Demand for quartz-based electrical devices is growing year by year due to widespread use in the multimedia field, especially as crystal oscillators, in mobile cellular phones, in SAW applications, and in digital still cameras. There is increasing demand for larger crystals with fewer line-defect and reduced inclusion of foreign particles. The main requirements for an autoclave for growing quartz crystals are a size of over 600 mm diameter, and up to 2,500 kg capacity. Numerical simulation of natural convection in an au-toclave with a baffle is performed with the finite element method. When the length of the heated part on the autoclave wall becomes greater than 2% of the height of the autoclave with 60% baffle closure, circulating flows in the upper and lower sections of the autoclave oscillate periodically. As the Rayleigh number is increased, the frequency and the amplitude of the flow oscillation increase.

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A Macro defect-free langasite (La_3Ga_5SiO_<14>) crystal 3" in diameter was grown along its Z-axis by the conventional Czochralski technique. The grown crystal represents clear faceting on (0001) and (011^^-0) faces, forming a basal Z plane and hexagonal columnar Y plane, respectively. Holding melt at the temperature close to the equilibrium melting temperature makes the supercooling degree appropriate for the development of the (0001) facet plane. A good balance between convection and surface stability of (0001) plane leads to the uniform interface during growth. The homogeneity in composition was investigated two-dimensionally by the X-ray Bond diffraction method. The congruent melt composition for langasite is also discussed relative to the stoichiometric composition.

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The liquid-phase epitaxial (LPE) growth of magneto-optic garnets for optical communication devices is reviewed.The main compositions of these garnets are oxides of rare earth, Bi, and Fe. Production of optical isolators using these garnets is now expanding Such isolators are used laser diode modules and optical fiber amplifiers m optical communication networks The magneto-optic properties of the garnets depend on the rare earth element used. For example, the temperature dependency of the Faraday rota tion is minimized when Tb is used. Partial substitution of Ga and/or Al for the Fe reduces the saturation magnetization field and induces magnetic hysteresis. LPE (liquid phase epitaxial) crystal growth of garnets with large diameters requires precise control of the crystal-lattice parameters of the LPE film because of the difference in thermal expansion coefficients between the substrate and film . Harmful optical absorption in the garnets overlapping the wavelength of the optical signals occurs if Pb or Pt is incorporated into the crystal. This absorption can be suppressed by growing the crystals at high temperature and/or by doping with an element such as Ti.

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The thin film of a Bi-Sn eutectic alloy coated with carbon films was melted partially in a transmission electron microscope and solidification processes were observed directly. Melting began along grain boundaries and spread around the region irradiated by an electron beam. The microscopic shape of a solid-liquid interface was uneven. By cooling at a rate of 8.3×10^<-3> K/s a part of a growth interface moved intermittently, and the heterogeneous nucleation and growth of grains occurred at the interface. In general, the grain consisting of a Sn-rich alloy (α phase) grew over a relatively wide region, while the growth of a grain consisting of mostly Bi (β phase) was limited in a small area. Moreover, some grains of β phase were dispersed and others were aligned discontinuously in an a matrix.

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To avoid the deviation of K_3Li_<2-x>Nb_<5+x>O_<15+2x> (KLN) crystal composition during the growth, an improved Czochralski technique , so called continue-charged Czochralski method, has been employed to offset the compositional change in melt during the growth by continually throwing calcined powder into the crucible, Using this method, the KLN crystal with composition of K_<3.00>Li<1.80> Nb_<5.20>O_<15.4> has been grown from melt of K_<3.00>Li_<2.63>Nb_<4.37> O_<13.74>-A 30 mm-long crystal was investigated for compositional deviation by measuring its transition temperature. The crystal was divided into 7 equal parts along the pulling direction, and their transition temperature were measured by a DSC equipment. The transition temperature of all samples were coincident with each other and determined to be 534℃ , indicating that the crystal is compositional deviation free and its concentration of Nb is 52 mol%. The crystals were transparent with an absorption edge at 370 nm, and showed a small optical absorption in the 420-900 nm region. Both ordinary and extraordinary optical indices were measured by the least declinate method, and then fitted to the Sellmeier's dispersion relation. The wavelength of second harmonic generation at the noncritical matching angle was determined at 816 nm. A blue SHG output beam with wavelength of 408 nm was observed. The nonliner optic coefficient is larger than that of LiNbO_3.

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