電漿輔助化學氣相沉積製程之模型分析與批次最佳化控制

Abstract

本論文主要探討在不同製程條件下電漿輔助化學氣相沉積(Plasma Enhance Chemical Vapor Deposition)機台沉積TEOS (四乙基矽氧烷 Si(OC2H4)4 ) Oxide薄膜之特性，首先選擇兩個輸入參數(腔體內壓力與O2氣體流量)與兩個輸出變數(沉積厚度與不均勻度)來建立PECVD系統模型，將輸入參數代入不同的數據，利用實驗設計法全因子的觀念尋找兩個輸入參數(腔體內壓力與O2氣體流量)與兩個輸出變數(沉積厚度與不均勻度)之間的關係。建立兩個PECVD系統模型，分別利用指數性加權移動平均(Exponential Weighted Moving Average，簡稱EWMA)控制器與最小遞迴平方（Recursive Least Square，簡稱RLS）控制器去控制，進行模擬分析與實驗，期望輸出參數可達目標值。期望晶圓沉積厚度誤差可控制在5%以內，不均勻度可控制在1.5%以下。沉積厚度與不均勻度控制的理想將可改善PECVD製程之良率。

In this thesis, we discuss with the property of PECVD equipment deposit TEOS Oxide film in different process conditions. First, we choose two input parameters (chamber pressure and the gas flow rate of O2) and two output variables(deposition thickness and ununiformity) to establish the model of PECVD system. Substituting different data into the input parameters, and using the DOE method to find the relationship between the two input parameters and the two output variables. We establish two PECVD system models respectively controlled by the EWMA controller and the RLS controller proceeding with simulation and experiment. We expect that the output variables can reach our target value that wafer deposition thickness error can be within 5% and ununiformity can be under 1.5%. As the controllers ideally control with the deposition thickness and ununiformity would improve the quality of PECVD process.