Solid State Studies with Isotopically Engineered Semiconductors

具有同位素控制组成的单晶（块状和层状结构）的特殊性质将用于自扩散和掺杂物扩散研究。利用二次离子质谱技术研究了70Ge - 74Ge超晶格中各层厚度约200纳米的内部同位素界面。第二阶段将研究具有更复杂扩散过程的材料。II-VI族直接带隙锌基化合物和氮化镓，蓝光发射体，将掺杂单同位素掺杂剂。它们将用局部振动模式光谱学进行研究。由同位素控制引起的杂质谱的简化有望使对局部杂质结构的认识达到一个新的水平。这些结果可能会导致尺寸不断减小、复杂性不断增加的器件的改进建模。冷战的结束开辟了从俄罗斯和乌克兰获得大量同位素高度富集的半导体材料的可能性。这些同位素纯材料将以一种全新的方式用于研究原子扩散。同一元素（例如锗70和锗74）的不同同位素的多层将通过薄膜晶体生长形成。界面上的相互扩散将用二次离子质谱进行研究。在研究了化学纯同位素结构之后，将研究一些用于光电子应用的新型半导体的掺杂体系和多层结构。振动;还将研究同位素纯半导体中一系列低质量杂质的光谱。这些结果将导致电子器件的建模精度不断降低，复杂度不断增加。＊＊＊

9417763 Haller The special properties of single crystals (bulk and Layered structures) with isotopically controlled composition will be used in self and dopant diffusion studies. Internal isotope interfaces in superlattices of 70Ge 74Ge with approximately 200 nanometer thick individual layers will be investigated by Secondary Ion Mass Spectroscopy. Materials with more complicated diffusion processes will be studied in the second phase. Group II-VI direct bandgap zinc based compounds and gallium nitride, blue light emitters, will be doped with mono-isotope dopants. They will be investigated using local vibrational mode spectroscopy. The simplification in impurity spectra caused by isotope control promises a new level of understanding of the local impurity structure. The results may lead to improved modeling of devices with ever decreasing dimensions and increasing complexity. %%% The end of the cold war has opened up the possibility of obtaining large quantities of isotopically highly enriched semiconductor materials from Russia and the Ukraine. These isotopically pure materials will be used to study atomic diffusion in a completely new way. Multilayers of different isotopes of the same elements (e.g. germanium 70 and 74) will be formed by thin film crystal growth. Interdiffusion at the interface will be investigated using Secondary Ion Mass Spectroscopy. After studying chemically pure isotope structures, doped systems and mutlilayers of some new semiconductors used in optoelectronics applications will be studied. The vibrational; spectra of a range of low mass impurities in isotopically pure semiconductors will also be investigated. The results will lead to improved modeling of electronic devices with every decreasing dimensions and increasing complexity. ***