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

低压、非平衡、放电（等离子体）工艺在微电子工业中用于沉积和蚀刻薄膜。等离子体增强化学气相沉积（CVD）技术实现了低温薄膜沉积，可以提供具有特殊材料性能和电子性能的新材料。等离子体刻蚀目前用于掩蔽材料、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等离子蚀刻。在这个行业中，加工很少自动化到很高的程度。实时监测和控制有助于利用等离子体蚀刻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收率。pi计划对等离子体蚀刻、反应离子蚀刻和CVD的数学模型和过程控制策略进行全面研究。等离子体沉积和蚀刻速率受到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。为了对这些系统进行建模和开发控制策略，计划进行理论和实验研究。一个利用径向流结构的研究蚀刻机，带有分析系统和数据采集已经建成，pi计划建造实验室规模的CVD设备。基于实验结果，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.