GOALI: Electrical and Structural Properties of Ion BSTO Thin Films for DRAM Applications

该项目的目标有两个：1)研究离子掺杂BaSrTiO （BSTO）薄膜的结构和电学性能，以及2)开发适合DRAM应用的基于BSTO材料的电容器。采用离子注入法制备了多晶BSTO薄膜。利用x射线衍射和透射电镜对植入膜进行了结构表征。用离子在物质中的输运程序模拟掺杂谱图，用二次离子质谱法对注入谱图进行表征。研究了AB03钙钛矿晶格中离子位置取代的影响。对BSTO薄膜的电学性能进行了全面的研究，重点研究了界面和体掺杂效应。要表征的电性能包括泄漏、介电松弛、电容密度、介电损耗、电阻退化、微波电容和C-V。除了供体和受体掺杂剂外，还研究了同价掺杂剂。离子注入可以调节BSTO薄膜中Ti的浓度。根据DRAM规格设计、制造和测试了不同的电容器结构。该项目不仅有助于理解钙钛矿氧化物薄膜的植入物掺杂效应，而且有助于开发下一代微电子先进的平面存储器件

9906274MaThe objectives of the project are twofold: 1) to study the structural and electrical properties of ion doped BaSrTiO (BSTO) thin films, and 2) to develop suitable capacitors based on BSTO material for DRAM applications. Ion implantation is used to dope polycrystalline BSTO thin films. Structural characterization of the implanted films is done by using X-ray diffraction and transmission electron microscopy. Doping profiles will be simulated with the program TRansport of Ions in Matter and the implanted profiles characterized by secondary ion mass spectroscopy. The effects of ion site substitution in the AB03 perovskite lattice is studied. A comprehensive investigation into the electrical properties of donor and acceptor doped BSTO thin films is carried out with an emphasis on interface vs bulk doping effects. Electrical properties to be characterized include leakage, dielectric relaxation, capacitance density, dielectric loss, resistance degradation, microwave capacitance, and C-V. In addition to donor and acceptor dopants, isovalent dopants are also investigated. Ion implantation could be used to adjust the Ti concentration in BSTO thin films. Different capacitor structures are designed, fabricated, and tested for the DRAM specifications. This project is expected to help not only in the understanding of the implant doping effects of perovskite oxide films, but also in the development advanced planar memory devices for the next generation microelectronics.***