晶圓製造廠各機種派工法則之系統化設定

Abstract

在〝半導體工廠生產計劃與排程系統構建之研究〞成果報告中，係應用限制理論的鼓－暫存區－繩 (drum-buffer-rope, DBR) 排程理念，來發展半導體製造工廠之階層式生產計劃和細部排程系統。其主要內容為依據較長期（三個月）的產能需求來決定瓶頸資源的排程；再以此瓶頸資源排程。制定短期關鍵資源之細部排程和進行非關鍵資源之產能規劃。由於非關鍵資源之派工績效將會影響細部排程目標的達成，本論文的主要目的即是針對非關鍵資源構建一套機器派工模組，使其派工績效能符合關鍵資源之排程目標。 非關鍵資源之派工模組內所考慮之機器型態除了一般機種（無特殊作業特性）外，透有爐管 (furnace) 和離子值入機 (implanter)。後二者分別具有成批處理 (batching) 和本組設置時間的性質。所採取之派工模式：一般機種為有效緊急優先法 (EEF)，以加工有效工件為優先考慮，爐管機種以選擇具有最小整體緊急成本 (MEC) 的載入配方和載入點為最佳的載入時點，離子值入機則以DKFAM的方法作為轉換子工件族的時機，並以EEF作為子工件族內工件的排序方法。此三種派工模式皆以預測晶圓批在上下游工作站之資訊，來增加派工決策之正確性。 運用DBR排程法時，暫存區 (Buffer) 和控制棒 (Rod) 長度的設定，是細部排程規劃階段重要的決策因子。而此二數值的長短和工廠負荷與交期設定之鬆緊程度有關，並進而影響派工模式的績效，所以本論文，亦探討了暫存區和控制棒長度的設定對機器派工成效之影響。

The main technique used in the NSC project, "Building the hierarchical production planning system for the semiconductor fabrication" is the drum-buffer-rope (DBR) scheduling, developed from theory of constrains (TOC) philosophy. This research builds a hierarchical production planning and detailed schedule planning system. The system first based on the capacity requests of a long period (three months) to determine a schedule plan for the bottleneck resource. Then according to the bottleneck resources schedule, it constructs detailed schedule of critical resources and proceeds the capacity planning for non-critical resources for a short period. However, the performance of dispatching may influence the achievement of the detailed schedule planning. This thesis therefore aims at constructing a dispatching module for non-critical resources to accomplish the goal of detailed schedule. The machine types discussed in the non-critical resources dispatching module include general type, furnaces and implanters. The general types of machine have no specific characteristics while the furnaces and implanters have the batch process and group set-up time characteristics respectively. The adoptions of dispatching rules are as follows. The effect-emergency rule is applied to general types of machines to give the effect parts the higher priority to process. The minimum-emergency-cost rule is applied to furnaces to choose the best loading recipe and the best loading time. The DKFAM rule is adopted for implanters to determine the time switching to process another subfamily, while the effect-emergency rule is used to sequence the parts belong to a subfamily. The forecasting information about the wafer in the upstream and downstream workstations are provided while a dispatching rule is applied so as to make a correct dispatching decision. When using DBR scheduling concept, the buffer and the rod length plays an important role in the detailed scheduling stage. This length relates to the load of a factory and the loose of due dates. It also affects the performance of the dispatching model. This thesis also discusses the influence of the buffer and the rod length on the dispatching performance.