CAREER: Materials and Processes for Microlithography, Patterning and Surface Modification (Nanoscale)

Clifford L.Henderson佐治亚理工学院微光刻技术是微电子器件中用于印刷电路元件的工艺，是半导体工业的关键技术驱动力。目前的微光刻技术正在接近其分辨率的极限(-180毫安)，必须开发新的材料和工艺以使该行业继续进步。如果不能开发出更先进、更高分辨率的图案化工艺，将导致半导体器件的毁灭性破坏。解决这一问题的双管齐下的方法将是提供一系列材料工艺，这些工艺可以是尺寸小于100纳米的图案特征。该项目的第一部分是针对改进现有光致抗蚀剂(光敏聚合物材料)材料以提供更高分辨率的研究。在现有材料的基础上开发更好的光刻胶和工艺的一个基本问题是，与测量控制其光刻性能的光刻胶的物理属性相关的困难，即由于曝光产生的酸的浓度和这种酸在聚合物基质中的扩散系数。如果没有这些知识，就很难合理地设计改进的材料和工艺。这项工作将开发一种新的革命性技术，该技术基于测量聚合物涂层交指电极(IDE)电容器的电容，可用于定量这种酸在光致抗蚀剂薄膜中的极少量酸浓度和扩散。这项技术将与包括微量滴定方法在内的其他酸度测量技术进行校准。将评估光刻胶的组成和工艺对该技术的准确性和灵敏度的影响。在这项工作中开发的方法和技术将通过与行业合作的方式转移到行业，包括与SEMATECH(行业研发联盟)的合作。这项技术将首次使用非侵入性、非破坏性技术来提取开发光致抗蚀剂性能预测模型所需的物理参数。这些模型可以用来指导改进的光刻胶材料和工艺的合理设计，这些光刻胶材料和工艺将能够重新定位小至130 nm的特征。目前光刻光刻胶材料和工艺的扩展不足以达到约130 nm以下的分辨率。为了达到这些分辨率，必须从当前的光学曝光系统(193 nm和248 nm光)改为所谓的“下一代光刻”工具(157 nm或13 nm光)。这种转换是一个巨大的挑战，因为目前使用的较高波长的光致抗蚀剂材料由于在这些真空-紫外光波长下的强吸收而无法发挥作用。因此，必须开发新的光致抗蚀剂材料和工艺，第二部分研究的目标是开发一种新型的表面成像光致抗蚀剂材料，该材料基于芳香单体在固体表面上的聚合，使用表面键合的光敏自由基引发剂。这些材料将使图案的生成精确到分子长度尺度。本项目将演示如何使用这些方法来形成低于100纳米的特征图案，并对控制这些材料性能的机制和系统参数有一个基本的了解。在表面沉积共价连接的聚合物薄膜允许在分子长度范围内控制表面的完整的物理化学性质。因此，除了半导体应用，这些材料还在生物工程、集成光学和其他将被探索的领域中有许多用途。四个主要的教育创新将被追求：(1)开发新的课堂，(2)修改现有的课程以包括非传统的跨学科问题，(3)实施基于互联网的教学和教学评估工具，(4)为学生创造多样化的跨学科研究体验。这些活动的一些具体目标是：(1)为学生提供机会学习包括微电子在内的化学工程师的前沿领域，(2)让半导体行业的学生积极参与教学活动，(3)展示基本工程原理在分析非传统问题中的应用，以及(4)提高未被充分代表的群体对微电子的兴趣和参与。

ABSTRACTCTS-9985196Clifford L. HendersonGeorgia Institute of Technology Microlithography, the process used to print circuit elements inMicroelectronic devices, is the key technology driver for thesemiconductor industry. Current microlithographic technologies arereaching the limits of their resolution (-180 ran) and new materials and processes must be developed to enable continued progress in theindustry. Failure to develop more advanced, higher resolutionpatterning processes would result in a devastating of semiconductordevices. A two pronged approach to solving this problem will be followed by providing a progression of materials processes that can be pattern features down below 100 nm in size. The first part of the projectdeals with research directed at improving current photoresist (the photosensitive polymeric materials) materials to provide higher resolutions. One of the fundamental problems with developing better photoresists and processes based on current materials is the difficulty associated with measuring the physical properties of the photoresist that govern its lithographic performance, i.e. concentration of acid generated due to exposure and diffusivity of this acid in the polymer matrix. Without this knowledge, it is difficult to rationally design improved materials and processes. This work will develop a new, revolutionary technique based on measuring the capacitance of polymer coated interdigitated electrode (IDE) capacitors which can be used for quantifying the extremely small acid concentrations and diffusion of this acid within the photoresist film. This technique will be calibrated against other acid measurement techniques including microtitration methods. The effect of photoresist composition and processing on the accuracy and sensitivity of this technique will be evaluated. The methods and technology developed in this work will be transferred to industry through operations with industry, including a collaboration with SEMATECH (an R&D consortium for the industry). This technique will make it possible for the first time using non-invasive, nondestructive techniques to extract the physical parameters required to develop predictive models for the performance of photoresists. These models can then be used to guide the rational design of improved photoresist materials and processes that will be capable of resoining features as small as 130 nm.The extension of current lithographic photoresist materials and processes is not sufficient to achieve resolutions below approximately 130 nm. To achieve these resolutions it will be necessary to change from current optical exposure systems (193 nm and 248 nm light) to so-called "Next Generation Lithography" tools (157 nm or 13 nm light). This conversion represents a substantial challenge since the current photoresist materials used at higher wavelengths will not function due to their strong absorbance at these vacuum-UV wavelengths. Thus, new photoresist materials and processes must be developed, The goal of the second part of the proposed research is to develop a novel surface imaging photoresist material based on the polymerization of aromatic monomers at solid surfaces using surfacebound photosensitive radical initiators. These materials will enable pattern generation down to molecular length scales. This project will demonstrate the use of such methods to pattern sub-100 nm features and develop a fundamental understanding of the mechanisms and system parameters that control the performance of these materials. The deposition of covalently linked polymer thin films on surfaces allows for the control of the complete physiochemical nature of surfaces over molecular length scales. Thus, in addition to semiconductor applications, these materials have a number of uses in bioengineening, integrated optics, and other areas that will be explored.Four main educational innovations will be pursued: (1) development of new classes, (2) modification of existing courses to include non-traditional interdisciplinary Problems, (3) implementation of internet based teaching and teaching evaluation tools, (4) creation of a diverse, interdisciplinary research experience for students. Some of the specific goals of these activities are to: (1) present students with opportunites to learn about frontier fields for chemical engineers including microelectronics, (2) engage the active participation of thesemiconductor industry in teaching activities, (3) demonstrate the application of fundamental engineering principles in the analysis of non-traditional problems, and (4) strengthen interest and involvement of under-represented groups in microelectronics.