This volume contains nearly all of the papers presented at the Symposium on "Defects and Qualities of Semiconductors" which was held in Tokyo on May 17-18, 1984, under the sponsorship of the SOCIETY OF NON-TRADITIONAL TECHNOLOGY. The Symposium was organized by the promoting committee of the research project "Quality Developement of Semiconductors by Utilization of Crystal Defects" sponsored by the Science and Technology Agency of Japan. Defect study in semiconductor engineering started originally with seeking methods how to suppress generation of harmful defects during device processing in order to achieve a high yield of device fabrication. Recently, a new trend has appeared in which crystal defects are positively utilized to improve the device performance and reliability. A typical example is the intrinsic gettering technique for Czochralski silicon. Thus, a new term "DEFECT ENGINEERING" was born. It is becoming more important to control density and distribution of defects than to eliminate all the defects. Very precise and deep knowledge on defects is required to establish such techniques as generation and development of defects desired depending on type of devices and degree of integration. Electrical, optical and mechanical effects of defects should be also understood correctly. Such knowledge is essential even for eliminating defects from some specified device regions. It is the time now to investigate defect properties and defect kinetics in an energetic way. From this point of view, all the speakers in this symposium were invited among the most active investigators in the field of defect engineering in Japan.

The world population in 1930 was 2 billion. It reached 3 billion in 1960, stands at 4. 6 billion today, and is expected to reach 6 billion by the end of the century. The food and fiber needs of such a rapidly increasing population are enormous. One of the most basic resources, perhaps the most basic of all, for meeting these needs is the soil. There is an urgent need to improve and protect this resource on which the future of mankind directly depends. We must not only learn how to use the soil to furnish our immediate needs, but also ensure that the ability of the soil to sustain food production in the future is unimpaired. This is indeed a mammoth task; a 1977 United Nations survey reported that almost one-fifth of the world's is now being steadily degraded. The diversity of soil makes it cropland necessary for research to be conducted in many locations. There are basic principles, however, that are universal. This, Advances in Soil Sciences, presents clear and concise reviews in all areas of soil science for everyone interested in this basic resource and man's influence on it. The purpose of the series is to provide a forum for leading scientists to analyze and summarize the available scientific information on a subject, assessing its importance and identifying additional research needs. But most importantly, the contributors will develop principles that have practical applications to both developing and developed agricultures.