應用動態模式最小變異控制器於先進微影製程控制

Abstract

本論文主要目的為設計一套應用於微影製程之關鍵尺寸(Critical Dimension，CD)的先進製程控制方法。利用實驗設計法(Design of Experiment， DOE)找出步進機之輸入變數(製程配方，recipes)與輸出變數(晶圓良率變數：關鍵尺寸)之間的關係，建立批次控制之預測模式，然後利用Recursive係數調變方法，做模式係數的動態調變，以適應製程隨時間變化之變異及干擾，再將已調變完成之模式代入最小變異控制器(Minimum Variance Controller，MVC)，使機台的輸入變數可以在改變量最小的限制下，即製程的變動最小的情形下，讓輸出變數快速地到達我們所設定的目標值，以提升製程之良率。

This thesis presents a new run-to-run (R2R) multiple-input-single-out controller for photolithography process. The controller, termed dynamical minimum variance controller, can act both as a dynamical model optimizer and as a controller for given models. In this thesis, the relationships and run-to-run control model among input recipes (Exposure dose and Focus) and output variables (Critical Dimension) are formed by using experimental design method. Then on-line (Recursive) model identification and recipes generation under input and output constraints are performed by using dynamical model optimizer and non-linear minimum variance controller, respectively. Improvements due to advanced control have been quantified in simulations and actual fab operations.