在機台群組限制下的黃光區投料派工模式

Abstract

晶圓製造的製程微小化是半導體工業發展的趨勢,而黃光微影製程在整體的製程微小化中,扮演最為重要的角色。在製程愈微小化後,為減少機台對製程的影響,而有對微影製程所使用的機台做機台群組的需求。機台群組,即為當產品於生產第一層的關鍵層時,若使用某微影對準機台,則後續的各關鍵層亦限定使用同一機台生產,以使各層間(overlay)能相互對準,減低製程變異。機台群組雖可增加品質穩定度,但也因為此限制,使原本已是瓶頸所在的微影機台,其生產管制作業更形複雜與困難。 本研究提出在機台群組的限制下,投料時對瓶頸-關鍵層微影機台做總負荷及區間負荷管制,以使各機台的負荷平均,不致造成在製品堆積或無貨可生產,在派工上, 以設定微影機台標準在製品量的方式,對供應微影機台的晶圓批做在製品的監控,若實際在製品低於標準在製品時,則提高上游供應的晶圓批的生產等級,以儘速供貨予瓶頸機台,使在機台群組的限制下,生產上的影響降至最低,進而達到提高機台利用率與總產出的目標。 由模擬結果可知,本研究所發展的方法,確實可有效提升機台利用率及總產出量,也可得到相對較佳的前置時間。

In semiconductor manufacturing, increasing device density by shrinking feature size towards deep sub-microns is the tendency for IC (Integrated Circuit) function enhancement and cost reduction. In this technology trend, photolithography becomes the most critical area in wafer process. In order to reduce the impact of tight process requirement, such as overlay in lithography, Stepper Grouping System is normally implemented to avoid machine-to-machine variation. Stepper Grouping System requires all critical layers to use the same stepper. It means if the first critical layer of lithography process uses stepper #1, the other critical layers will have to use this stepper later on to reduce process variance. This limitation can guarantee process stability. But it makes production control very complicate because of less flexibility. Due to the stepper grouping limitation and the fact that steppers are normally the bottleneck in wafer fabrication, this research will focus on the development of wafer release and dispatching model to reduce production impact that comes from stepper grouping. To balance loading and keep WIP for each stepper are the key points of wafer release and dispatching model that developed in this research respectively. Simulation results shows the model developed in this study gives better performance than the others tested rule in terms of stepper utilization, throughput, and cycle time. 英文摘要………………………………………………………ii 誌謝……………………………………………………………iii目錄……………………………………………………………iv 表目錄………………………………………….………………v 圖目錄…..…………………………………….……………….vi 符號說明…………….…………………………………….….vii 第一章 緒論……………………………..………………….…1 1.1 研究動機……………………………………………..…….1 1.2 研究目的…………………………………………….…..…6 1.3 研究步驟……………………………….………………..…7 第二章 文獻探討…………………….…..…………………....9 第三章 模式構建……………….……………………….……13 3.1 投料法則的構建……………………………..……………...15 3.2 派工法則的構建……………….….…………………………..21 第四章 模擬驗證…………………..………………………...…25 iv 4.1 模擬模型的構建資料………………………..…………...…25 4.2 基本假設………………………………………………….…25 4.3 模擬驗證………………………………………………..……26 第五章 結論與建議…………….………………………..….…33 5.1 結論…………………………………………………..……33 5.2 建議…………………………………………………..……34 參考文獻………………………………………….………..…35 附錄……………………………………………….……….…viii