АНАЛИЗ КАЧЕСТВА ПОДЗАТВОРНОГО ДИЭЛЕКТРИКА МОП-СТРУКТУР ПО ВОЛЬТ-ФАРАДНЫМ ХАРАКТЕРИСТИКАМ

There were investigated the capacity-voltage characteristics of the MOS transistors, fabricated by the similar process charts, with the identical applied technological materials), however at various time (appropriately further in the text series A and series B). It was shown, that the measurements of the capacityvoltage characteristics of the MOS structures make it possible to perform the quality diagnostics of the gate dielectric. The kind and shape of the measured characteristics are determined by the value of the additional positive charge in the dielectrics and density of the fast surface states on the Si-SiO2 interface, which correlate with the surface concentration of the technological impurities, adsorbed on the surface of the wafers in process of the devices fabrication, which makes it possible to make a conclusion about the quality of the applied materials and compliance of the manufacturing process. Исследованы МОП-транзисторы методом вольт-фарадных характеристик, изготовленных в разное время, но по аналогичным технологическим маршрутам и при использовании идентичных технологических материалов. Установлено, что измерения вольтфарадных характеристик МОП-структур позволяют проводить диагностику качества подзатворного диэлектрика. Вид и форма измеренных характеристик определяются величиной дополнительного положительного заряда в объеме диэлектрика и плотностью быстрых поверхностных состояний на границе раздела Si-SiO2, которые коррелируют с поверхностной концентрацией технологических примесей, адсорбированных на поверхности пластин в процессе изготовления приборов, что позволяет сделать заключение о качестве используемых материалов и соблюдении технологических режимов.

ВЛИЯНИЕ ТЕХНОЛОГИЧЕСКИХ ПРИМЕСЕЙ НА ВОЛЬТ-АМПЕРНЫЕ ХАРАКТЕРИСТИКИ БИПОЛЯРНОГО n–p–n-ТРАНЗИСТОРА

Contamination of the monocrystal silicon with technological impurities in the devices fabrication process exerts a considerable influence on the electro-physical characteristics of the bipolar n–p–n-transistors. Revelation of the causes of the labile reproducibility of the basic characteristics of the bipolar planar n–p–n-transistors is vital for the purpose of establishing the factors, determining reliability and stability of the operational parameters of the integrated circuits. There were investigated I–V characteristics of the various lots of the bipolar n–p–n-transistors, fabricated under the epitaxialplanar technology as per the similar process charts with the identical used technological materials, however, at different times. It is established that the electro-physical characteristics of the bipolar n–p–n-transistors substantially depend on the contents of the technological impurities in the substrate material. Availability of the high concentration of the generation-recombination centers, related to the metallic impurities, results both in increase of the reverse current of the collector – base junction of the transistors and the significant reduction of the breakdown voltage of the collector junction. The most probable cause of deterioration of the electro-physical parameters of the bipolar n–p–n-transistors is the material contamination with the technological impurities (such, as Fe, Cl, Ca, Cu, Zn and others) during the production process of the devices fabrication. The sources of impurity may be both the components and sub-assemblies of the technological units and the materials and reagents under usage.Загрязнение монокристаллического кремния технологическими примесями в процессе изготов- ления приборов оказывает существенное влияние на электрофизические характеристики биполярных n–p–n-тран- зисторов. Выявление причин лабильной воспроизводимости основных характеристик биполярных планарных n–p–n-транзисторов является актуальным с целью установления факторов, определяющих надежность и стабильность эксплуатационных параметров интегральных микросхем. Исследованы вольт-амперные характеристики различных партий биполярных n–p–n-транзисторов, изготовленных по эпитаксиально-планарной технологии по аналогичным технологическим маршрутам, при идентичных используемых технологических материалах, однако в различное время. Установлено, что электрофизические характеристики биполярных n–p–n-транзисторов существенным образом зависят от содержания технологических примесей в материале подложки. Наличие высокой концентрации генерационно-рекомбинационных центров, связанных с металлическими примесями, приводит как к увеличению обратного тока через переход коллектор–база транзисторов, так и к существенному снижению напряжения пробоя коллек- торного перехода. Наиболее вероятной причиной ухудшения электрофизических параметров биполярных n–p–nтранзисторов является загрязнение материала технологическими примесями (такими, как Fe, Cl, Ca, Cu, Zn и др.) во время производственного процесса изготовления приборов. Источниками загрязнений могут служить как детали и узлы технологических установок, так и используемые материалы и реактивы

Cluster ion beam facilities

A brief state-of-the-art review in the field of cluster-surface interactions is presented. Ionised cluster beams could become a powerful and versatile tool for the modification and processing of surfaces as an alternative to ion implantation and ion assisted deposition. The main effects of cluster-surface collisions and possible applications of cluster ion bieams are discussed. The outlooks of the Cluster Implantation and Deposition Apparatus (CIDA) being developed in Goteborg University are shown

QUALITY ANALYSIS OF THE GATE DIELECTRIC OF THE MOS-STRUCTURES BY CAPACITY-VOLTAGE CHARACTERISTICS

There were investigated the capacity-voltage characteristics of the MOS transistors, fabricated by the similar process charts, with the identical applied technological materials), however at various time (appropriately further in the text series A and series B). It was shown, that the measurements of the capacityvoltage characteristics of the MOS structures make it possible to perform the quality diagnostics of the gate dielectric. The kind and shape of the measured characteristics are determined by the value of the additional positive charge in the dielectrics and density of the fast surface states on the Si-SiO2 interface, which correlate with the surface concentration of the technological impurities, adsorbed on the surface of the wafers in process of the devices fabrication, which makes it possible to make a conclusion about the quality of the applied materials and compliance of the manufacturing process

QUALITY ANALYSIS OF THE GATE DIELECTRIC OF THE MOS-STRUCTURES BY CAPACITY-VOLTAGE CHARACTERISTICS

There were investigated the capacity-voltage characteristics of the MOS transistors, fabricated by the similar process charts, with the identical applied technological materials), however at various time (appropriately further in the text series A and series B). It was shown, that the measurements of the capacityvoltage characteristics of the MOS structures make it possible to perform the quality diagnostics of the gate dielectric. The kind and shape of the measured characteristics are determined by the value of the additional positive charge in the dielectrics and density of the fast surface states on the Si-SiO2 interface, which correlate with the surface concentration of the technological impurities, adsorbed on the surface of the wafers in process of the devices fabrication, which makes it possible to make a conclusion about the quality of the applied materials and compliance of the manufacturing process