Việc sử dụng các yếu tố như antimon, asen, gallium và indium từ lâu đã được đặc trưng, trong sản xuất chất bán dẫn cho các chip máy tính, điện thoại di động, và điốt phát sáng (LED). Trong 30 năm qua, hàng chục tấn của những yếu tố này đã được tích hợp vào các thiết bị này hoặc như dopants (1,2) cho các chip máy tính dựa trên silicon hoặc trong sản xuất cao hơn tốc độ các chất bán dẫn III-V như gallium arsenide hoặc indium arsenide (2). Do nhu cầu cho các thiết bị tốc độ. | 18 Semiconductors Bruce A. Fowler and Mary J. Sexton University of Maryland Baltimore Maryland 1. INTRODUCTION The use of elements such as arsenic antimony gallium and indium has long been featured in the manufacture of semiconductors for computer chips cellular telephones and light emitting diodes LEDs . Over the last 30 years tens of tons of these elements have been incorporated into these devices either as dopants 1 2 for silicon-based computer chips or in the manufacture of the higher-speed III-V semiconductors such as gallium arsenide or indium arsenide 2 . As the demand for higher-speed devices has increased older devices with slower electronic speeds have been discarded in the absence of well-established recycling programs generating a large stockpile of electronic devices containing these elements collectively known as e-waste. The magnitude of this growing problem has only recently been appreciated in California and Europe 3 but much about the biological properties of these high-technology materials is not yet known. Experimental animal studies 4-9 have demonstrated that particles of GaAs or InAs are broken down in vivo resulting in the release of both constitutive elements 4-9 . This creates a binary chemical mixture situation raising the issue of interactive effects. The situation in the semiconductor manufacturing plants is even more complex since a number of solvents are also present and semiconductor workers are exposed to a number of toxic agents in the clean room environ- Copyright 2002 Marcel Dekker Inc. ments 10 . Epidemiological studies of these workers have shown an increased incidence of miscarriages and there are case reports of brain and testicular cancers among workers employed in a gallium arsenide plant. This chapter will review the known biological effects of arsenic including arsine gas 11-16 antimony 17 gallium 18 and indium 19 from the perspective of experimental systems and attempt to relate these data to the findings of .
