Development of Mathematical Models and Control Strategies for Solid State Device Processing

在微电子工业中，使用低压、非平衡、放电(等离子体)工艺来沉积和蚀刻薄膜。等离子体增强化学气相沉积(CVD)技术可以在较低的温度下沉积薄膜，为新材料提供特殊的材料和电学性能。等离子体刻蚀目前用于掩膜材料、硅、含硅材料、化合物半导体和金属的刻蚀。在一个典型的微芯片的生产中，十个或更多的步骤可能涉及到等离子体刻蚀。在这个行业中，加工很少达到高度自动化。实时监测和控制可以帮助利用等离子体刻蚀中可用的精细几何转移，并通过引入工艺变量的动态处理来提高工艺产量。PIS计划对等离子刻蚀、反应离子刻蚀和CVD的数学模型和工艺控制策略进行全面研究。等离子体沉积和刻蚀速率受大量工艺变量的影响，包括气体成分、压力、温度、反应器几何形状、放电频率和功率。为了模拟和开发这类系统的控制策略，计划进行理论和实验研究。已经建造了一个利用径向流动结构和分析系统和数据采集的研究蚀刻器，PI计划建造实验室规模的CVD设备。根据实验结果，将建立和验证物理化学模型，然后制定和实施动态和稳态控制策略。

Low pressure, nonequilibrium, electric discharge (plasma) processes are used in the microelectronics industry to deposit and etch thin films. Plasma enhanced chemical vapor deposition (CVD) enables film deposition at low temperatures and can provide new materials with special material and electronic properties. Plasma etching is presently used for etching of masking materials, silicon, silicon-containing materials, compound semiconductors, and metals. In the production of a typical microchip, ten or more steps may involve plasma etching. In this industry, processing is rarely automated to a high degree. Real- time monitoring and control could aid in exploiting the fine geometry transfer available in plasma etching as well as increase process yields by introducing dynamic treatment of process variables. The PIs plan a comprehensive study of mathematical models and process control strategies for plasma etching, reactive ion etching and CVD. Plasma deposition and etch rates are affected by a large number of process variables including gas composition, pressure, temperature, reactor geometry, electric discharge frequency, and power. To model and develop control strategies for such systems both theoretical and experimental studies are planned. A research etcher utilizing a radial flow configuration with analytical systems and data acquisition has already been constructed and the PIs plan to construct laboratory-scale CVD apparatus. Based on experimental results, physico-chemical models will be developed and verified followed by the formulation and implementation of both dynamic and steady state control strategies.