Fabrication and Characterization of High Temperature Nanostructures

9976577 Snider几十年来，微电子行业的增长速度在历史上是无与伦比的。 这种增长的引擎是场效应晶体管（FET），虽然今天的FET与1970年的FET相去甚远，但它仍然是FET。 现代集成电路中的晶体管被用作电流开关，这与康拉德·楚泽在20世纪30年代使用的机电继电器没有什么不同。 半导体工业协会（SIA）的路线图呼吁继续依赖场效应晶体管，直到2010年，但在此之后的道路是不清楚的。 为了实现更高的集成度，需要一种方法来避免出现在非常小的FET中的不良影响。 该行业的一条可能的道路是转向基于纳米结构而不是FET的范式。在纳米结构中，器件性能通常随着尺寸减小而改善。 工作温度可能是采用纳米结构的最大障碍。 大多数纳米结构仅在接近液氦的温度下起作用。 第二个障碍是需要新的电路结构，因为纳米结构制造的晶体管性能很差。 提出了一种新的基于AFM氧化的制备技术，以制备工作温度在20至77 K范围内的纳米结构器件。 在这个过程中，金属膜通过阳极氧化形成图案，由AFM控制，然后与下面的硅层反应形成硅化物。 硅化物从每一侧底切氧化物线，使线变窄，并有效地增加图案化的分辨率。 这个过程将产生具有比使用常规AFM氧化可能的更窄的隧道势垒的纳米结构。 更窄的势垒可以降低结电阻，提高器件速度。新工艺将用于制造量子点细胞自动机（QCA）细胞。 QCA是一种基于纳米结构优势的架构，使用它们来存储电荷而不是切换电流。 在QCA范式中，信息由形成细胞的量子点簇中的电子位置编码。 QCA单元的状态通过库仑相互作用由其相邻单元的状态决定，并且单元的适当布置可以实现任何逻辑功能。 以前的实验已经证明了一个基本的QCA细胞，细胞线，和一个AND/OR门的操作。 新的AFM硅化物工艺的应用将使在更高温度下工作的更大阵列QCA电池成为可能。*

9976577SniderFor decades the microelectronics industry has enjoyed growth that is unparalleled in history. The engine of this growth is the field effect transistor (FET), and while the FET of today is a far cry from that of 1970 it is still an FET. Transistors in modem integrated circuits are used as current switches not unlike the electromechanical relays used by Konrad Zuse in the 1930s. The Semiconductor Industry Association (SIA) roadmap calls for continued dependence on FETs until the year 2010, but after that time the path is unclear. To achieve ever higher integration levels will require an approach that avoids the undesirable effects that appear in very small FETs. One possible path for the industry is a switch to a paradigm based on nanostractures rather than FETs. In nanostructures, the device performance typically improves as the size decreases. Operating temperature is perhaps the greatest obstacle to the adoption of nanostructures. Most nanostructure function only at temperatures near that of liquid helium. A second obstacle is the need for new circuit architecture, since nanostructures make poor transistors.This proposal seeks to address both of these obstacles. A novel fabrication technique based on AFM oxidation is proposed, to produce nanostructure devices with an operating temperature in the range of 20 to 77K. In this process a metal film is patterned by anodic oxidation, controlled by the AFM, and then reacted with the underlying silicon layer to form a silicide. The silicide undercuts the oxide line from each side, narrowing the line and in effect increasing the resolution of the patterning. This process will produce nanostructures with narrower tunnel barriers than are possible using conventional AFM oxidation. Narrower barriers give a lower junction resistance and increased device speed.The new process will be used to fabricate quantum-dot cellular automata (QCA) cells. QCA is an architecture which builds upon the strengths of nanostructures, using them to store charge rather than to switch currents. In the QCA paradigm information is encoded by the positions of electrons in a cluster of quantum dots forming cell. The state of a QCA cell is determined by the state of its neighboring cells through the Coulomb interaction, and proper arrangements of cells can implement any logic function. Previous experiments have demonstrated the operation of a basic QCA cell, a line of cells, and an AND/OR gate. Application of the new AFM silicide process will make it possible to demonstrate larger arrays of QCA cells operating at higher temperatures.***