Small Grants for Exploratory Research: Nanofabrication Techniques Based on Two Levels of Molecular Self-Assembly Self-Assembled Monolayers & Ordering of Block Copolymers

Nealy, Paul F. U of Wisconsin, Madison .该提案的短期研究目标是演示下面描述的抗蚀系统的使能技术。本探索性研究小额拨款提案支持对控制疏水/亲水表面上两亲嵌段共聚物薄膜有序的界面现象的研究。光学光刻技术是制造微电子器件最广泛的技术，它所能制造的特征尺寸正在接近下限（100纳米）。与此同时，对更密集、更快和更强大的电路的需求将继续下去，这一点毫无疑问。更小的特征（50nm）可以用电子束书写或触针光刻生产。然而，这些工艺目前是串行的，需要大量开发才能实现大批量的商业应用。基于短波辐射的光刻技术，例如极紫外光（EUV）和x射线光刻（XRL），具有所需的分辨率。但目前还没有适合100nm以下应用的抗蚀材料。目前的抗蚀剂系统依赖于动力学过程，如扩散和溶解。控制这些系统的原则不能在纳米范围内盲目地推断，因为微小的公差和边际会消失。新的纳米级抗蚀剂体系必须能够产生具有分子尺寸公差和原子尺寸边缘的特征。提出的长期研究目标是开发一种基于界面现象和两个分子水平的纳米制造技术：自组装单层（SAMs）和有序的块层薄膜，因为它导致平衡结构处于（或接近）热力学最小值。自组装单层（SAMs）将在衬底表面形成，并且SAMs将在两亲嵌段共聚物的平面上形成图案并沉积在衬底上，并且表面能将控制退火后强分离共聚物的有序。如果模式化的sam的尺寸与聚合物分子的尺寸具有相同的数量级，那么聚合物薄膜中的结构将被诱导为与衬底垂直。低表面能的区域将被聚合物的疏水嵌段覆盖，而高表面能的区域将被聚合物的亲水嵌段覆盖。预计传播的顺序将贯穿沉积薄膜的整个厚度。嵌段共聚物的一个嵌段将被选择性地蚀刻。横向尺寸为几十纳米的任意形状的图案将以x射线光刻的分辨率从图案的sam转移到抗蚀剂材料（共聚物的剩余块）上。

ABSTRACT CTS-9708944 Nealy, Paul F. U of Wisconsin, Madison The proposal's short-term research goal is to demonstrate the enabling technology for the resist system described below. This proposal for a Small Grants for Exploratory Research supports the investigation of the interfacial phenomena that govern the ordering of thin films of amphiphilic block copolymers on patterned hydrophobic/hydrophilic surfaces. Optical lithography, the most widespread technique for the fabrication of microelectronic devices, is approaching the lower limit (100 nm) in the size of features that it can produce. At the same time, there is little doubt that the need for denser, faster and more powerful circuits will continue. Smaller features (50nm) can be produced with electron beam writing or stylus lithography. These processes, however, are currently serial and will require significant development for high-volume commercial applications. Lithographies based on shorter wavelength radiation, for example extreme ultra violet (EUV) and X-ray lithography (XRL), have the required resolution. but no satisfactory resist materials exist for applications below 100 nm. Current resist systems rely on kinetic processes such as diffusion and dissolution. The principles that govern these systems cannot be blindly extrapolated in the nanometer regime because of vanishing small tolerances and margins. New resist systems for the nanometer regime must be able to produce features of molecular dimensions with tolerances and margins of atomic dimensions. The proposed long -term research goal is to develop a nanofabrication technique based on interfacial phenomena and two levels of molecular: self-assembled monolayers (SAMs) and ordering of thin films of block because it leads to equilibrium structures that are at (or close to) thermodynamic minimum. Self-assembled monolayers (SAMs) will be formed on the surface of a substrate, and the SAMs will patterned in the plane of the amphiphilic block copolymer will be depos ited on the substrate, and surface energy will govern the ordering of the strongly segregating copolymer upon annealing. If the dimensions of the patterned SAMs are of the same order of magnitude as the dimensions of the polymer molecules, then structure in the polymer film will be induced normal to the substrate. Regions of low surface energy will be covered with the hydrophobic block of the polymer, and regions of high surface energy will be covered with the hydrophilic block of the polymer. It is expected that the order to propagate will pass through the entire thickness of the deposited film. One of the blocks of the block copolymer will be selectively etched. Arbitrarily shaped patterns with lateral dimensions of tens of nanometers will be transferred from the patterned SAMs to resist material (the remaining block of the copolymer) at the resolution of X-ray lithography.