Fabrication and Characterization of High Temperature Nanostructures

高温纳米结构的制备和表征

• 批准号: 9976577
• 负责人: Gregory Snider
• 金额: $ 18万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-15 至 2003-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9976577&HistoricalAwards=false
• 关键词: Fabrication; Characterization; Temperature; Nanostructures

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.***

9976577SNIDER数十年来，微电子行业的增长在历史上是无与伦比的。 这种增长的发动机是现场效应晶体管（FET），尽管今天的FET远与1970年的FET相去甚远，但它仍然是FET。 调制解调器集成电路中的晶体管用作电流开关，与1930年代Konrad Zuse使用的机电继电器不同。 半导体行业协会（SIA）路线图要求持续依赖FET，直到2010年，但此后的道路尚不清楚。 为了达到更高的整合水平，将需要一种方法，以避免出现很小的FET中出现的不良影响。 该行业的一项可能途径是基于纳米折扣而不是FET的范式切换到范例。在纳米结构中，设备性能通常会随着尺寸降低而提高。 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液体氦气附近的温度下功能。 第二个障碍是需要新的电路架构，因为纳米结构使晶体管变得差。该提案旨在解决这两个障碍。 提出了一种基于AFM氧化的新型制造技术，以生产具有20至77K范围的工作温度的纳米结构设备。 在此过程中，金属膜由阳极氧化图案化，由AFM控制，然后与下面的硅层反应形成硅化硅。 硅化剂从两侧削弱了氧化物线，缩小了线条并实际上增加了图案的分辨率。 此过程将产生与常规AFM氧化相比，具有较窄的隧道屏障的纳米结构。 较窄的屏障具有较低的连接阻力和增加的设备速度。新过程将用于制造量子点蜂窝自动机（QCA）细胞。 QCA是一种建立在纳米结构的强度基础上的建筑，它使用它们存储充电而不是切换电流。 在QCA范式中，信息由电子在形成单元的量子点群中的位置编码。 QCA细胞的状态取决于其相邻细胞的状态，通过库仑相互作用，正确的细胞排列可以实现任何逻辑函数。 先前的实验证明了基本QCA单元，一系列单元和/或栅极的操作。 新的AFM硅化过程的应用将使在较高温度下运行的较大QCA细胞成为可能。***