砷化鎵磊晶製程之勞工相似暴露群評估

Abstract

砷化物廣泛的分布於自然界中，可能經由工業製程等方式進入生活環境中，且砷是一種會累積之毒性元素，其化合物之毒性會隨化學型態、攝入體內之途徑、劑量及暴露期間的不同而有極大的差異。砷化氫(AsH3)氣體可引起溶血，再嚴重時則產生急性腎管狀細胞壞死，最後可能導致腎衰竭。 發光二極體(Light Emitting Diode:LED)是化合物半導體的一種，主要由Ⅲ族（硼、鋁、鎵、銦）、Ⅴ族元素（磷、砷、銻）組成，LED具有體積小、壽命長、驅動電壓低、反應速度很快(約在10^-9秒)等優點，一般應用於交通號誌及各種室內、外顯示用看板。在四元的發光二極體磊晶製程中，砷化氫是磊晶的主要原料之ㄧ。 風險管理觀念在國外職場漸普及各種作業環境，美國工業衛生協會中暴露評估策略委員會(AIHA, American Industrial Hygiene Association)曾發表有關職業暴露評估與處理策略，係對職場全廠區各種負荷評估，並介紹相似暴露群概念，以健康效益等級HER(health effect rating)、暴露等級ER(exposure rating)兩項健康風險等級(health risk rating)及不確定度UR(uncertainty rating)作職場整體危害之評分，希望能選擇高風險族群作為優先控管對象，以有效降低勞工暴露風險。 本研究試圖以AIHA所發表職業暴露評估與處理策略作基礎，以發光二極體磊晶製程的砷暴露勞工為主要評估對象，進行作業型態調查、機台製程調查、危害物之基礎物理化學或危害特性調查，並依製程、工作項目、工作性質、暴露危害物等建立作業暴露分析，建立相似暴露群，收集歷年的作業環境測定資料、健康檢查結果進行分析。由研究結果得知作業環境中的砷濃度分布範圍為N.D.~0.134 mg/m3，遠小於法規之容許濃度0.5 mg/m3，管件清洗區的砷濃度略高於磊晶機台區，健康影響評估方面，年度健康檢查之血紅素測定有大部分人員符合標準，而僅一組數據有顯著相關性存在。

As compound distributes evenly in the natural word. It might enter into living environment via the industrial manufacture process. Nevertheless, As is one kind of accumulative toxic element. The toxicity of As compound varies substantially with the chemical pattern, absorption path to human body, dose and exposure duration. Gaseous AsH3 can cause hemolysis, even worse, the destruction of tubulogenesis cell, leading to renal failure probably. Light Emitting Diode (LED) is one kind of compound semiconductors, constituted by the elements of Group III and V. LED has the advantages of small size, long duration, low driving potential and quick response (~10-9 sec.). It is generally used in the traffic signal, outdoor display plate. In the manufacture process of Epitaxy, AsH3 is one of the primary raw materials. The idea of risk management becomes popular in the working places and processing environments worldwide. The committee of exposure evaluation strategy of AIHA (American Industrial Hygiene Association) has issued the reports concerning on professional exposure and management strategy. They focus on the various load evaluations around the facility areas and introduce the idea of Labor Similar Exposure Group. The hazardous evaluation of working place is based on the two health risk ratings, such as HER (health effect rating) and ER (exposure rating), and the UR (uncertainty rating). It is intended to select the high-risk group as the control target to lower down the labor exposure risk effectively. The research intends to apply the exposure evaluation and management strategy of AIHA as the fundamentals to assess the labor As exposure risk during LED Epitaxy Manufacture process. Such evaluation includes the investigations of working pattern, workstation, physical and chemical properties of HPM, and also bases on the manufacture process, working item and characteristics, and exposure of HPM to establish the exposure analysis and similar exposure group. The analyses also need the input data from the environmental measurements and physical examinations of workers. From the research analyses, it is found that the distribution of As concentration ranges from N.D. to 0.134 mg/m3 in the working environment, whose value is much less 0.5 mg/m3 regulated by law. In the pipe cleaning area, its As concentration is a little higher than that in Epitaxy workstation area. For the evaluation of healthy influence, the most workers’ Hemoglobin test results meet the standards, and only one set of data show the existence of correspondence.