硅是最常用于集成电路(IC)制造的原料。它是地球上最丰富的物质。它是从岩石和公共海滩砂中提取,并通过详尽的净化过程。在这种形式中,硅是人类产生的纯工业物质,其杂质包括少于一百分点。这是一串从地球到月球伸展的高尔夫球中的一个网球。半导体通常具有小于2EV的能带间隙的材料。半导体的一个重要特性是通过掺杂来改变几个数量级的电阻率的能力。半导体在10-5和107欧姆之间具有电阻率。半导体可以是结晶或无定形的。元素半导体是简单元件半导体材料,如硅或锗。

硅是当今最常用的半导体材料。适用于二极管、晶体管、集成电路、存储器、红外线检测和镜头,发光二极管(LED),光电传感器,应变计,太阳能电池,电荷转移装置,辐射检测器和各种其他装置。硅属于周期表中的IV族。它是一种灰色脆性材料,具有钻石立方结构。硅是常规掺杂磷,砷和锑和硼,铝和镓受体。硅的能隙是1.1eV。该值允许在比锗的较高温度下的硅半导体器件的操作。在1900年代早期,在本发明的集成电路和硅芯片之前,使用真空管进行了计算机和无线电。真空管是由Dr.Lee Demorest博士发明的1906。整个20世纪上半叶,使用真空管进行,调节和放大电信号。他们成为各种新产品,包括收音机和计算机。 However vacuum tubes had some inherent problems. They were bulky, delicate and expensive, consumed a great deal of power, took time to warm up, got very hot, and eventually burned out. The first digital computer contained 18,000 vacuum tubes, weighed 50 tins, and required 140 kilowatts of power. By the 1930’s, researchers at the Bell Telephone Laboratories were looking for a replacement for the vacuum tube. They began studying the electrical properties of semiconductors which are non-metallic substances, such as silicon, that are neither conductors of electricity, like metal, nor insulators like wood, but whose electrical properties lie between these extremes. By 1947 the transistor was invented. The Bell Labs research team sought a way of directly altering the electrical properties of semiconductor material. They learned they could change and control these properties by “doping” the semiconductor, or infusing it with selected elements, heated to a gaseous phase. When the semiconductor was also heated, atoms from the gases would seep into it and modify its pure, crystal structure by displacing some atoms. Because these dopant atoms had different amount of electrons than the semiconductor atoms, they formed conductive paths. If the dopant atoms had more electrons than the semiconductor atoms, the doped regions were called n-type to signify and excess of negative charge. Less electrons, or an excess of positive charge, created p-type regions. By allowing this dopant to take place in carefully delineated areas on the surface of the semiconductor, p-type regions could be created within n-type regions, and vice-versa. The transistor was much smaller than the vacuum tube, did not get very hot, and did not require a headed filament that would eventually burn out. Finally in 1958, integrated circuits were invented. By the mid 1950’s, the first commercial transistors were being shipped. However research continued. The scientist began to think that if one transistor could be built within one solid piece of semiconductor material, why not multiple transistors or even an entire circuit. Within a few years this speculation became one solid piece of material. These integrated circuits(ICs) reduced the number of electrical interconnections required in a piece of electronic equipment, thus increasing reliability and speed. In contrast, the first digital electronic computer built with 18,000 vacuum tubes and weighed 50 tons, cost about 1 million, required 140 kilowatts of power, and occupied an entire room.

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氯氟烃:用途和危险

今天,一个完整的电脑,用一块儿童指甲大小的硅片制造,只需要10美元。在IC实际创建之前,创建一个比实际尺寸大400倍的大型绘图。制造一个集成电路大约需要一年的时间。然后他们要做一个面具。根据复杂程度的不同,一个集成电路将需要5到18个不同的玻璃掩模,或“工作板”来创建必须转移到硅片表面的电路图案层。面具的制作从一种叫做MEBES的电子束曝光系统开始。MEBES通过向化学镀膜的玻璃板发射强电子束,将图形产生磁带上的数字化数据转换成物理形式。其结果是精确绘制出单个电路层的精确尺寸,通常小于四分之一平方英寸。以令人难以置信的精确度,它可以制造出人类头发丝宽度的六十分之一的线条。经过提纯后,熔融硅被掺杂,以赋予它特定的电特性。 Then it is grown as a crystal into a cylindrical ingot. A diamond saw is used to slice the ingot into thin, circular wafers which are then polished to a perfect mirror finish mechanically and chemically. At this point IC fabrication is ready to begin. To begin the fabrication process, a silicon wafer (p-type, in this case) is loaded into a 1200 C furnace through which pure oxygen flows. The end result is an added layer of silicon dioxide (SiO2), “grown” on the surface of the wafer. The oxidized wafer is then coated with photoresist, a light-sensitive, honey-like emulsion. In this case we use a negative resist that hardens when exposed to ultra-violet light. To transfer the first layer of circuit patterns, the appropriate glass mask is placed directly over the wafer. In a machine much like a very precise photographic enlarger, an ultraviolet light is projected through the mask. The dark pattern on the mask conceals the wafer beneath it, allowing the photoresist to stay soft; but in all other areas, where light passes through the clear glass, the光致抗蚀剂硬化。然后将晶片洗涤在去除软光致抗蚀剂的溶剂中,但在晶片上留下硬化的光致抗蚀剂。除去光致抗蚀剂的情况下,氧化物层暴露。蚀刻浴除去这种暴露的氧化物,以及剩余的光致抗蚀剂。仍然是掩模图案的模板,以微小的氧化物和硅的形式。

读:
中国针灸:使用与技术

晶圆片被放置在扩散炉中,扩散炉将充满气体化合物(所有n型掺杂剂),这一过程称为杂质掺杂。在热风炉中,掺杂剂原子进入暴露的硅区域,形成n型材料的图案。蚀刻槽去除剩余的氧化物,在晶圆上沉积一层新的硅(n-)。现在芯片的第一层已经完成,掩盖过程再次开始:一层新的氧化物生长,晶圆被涂上光刻胶,第二层掩模暴露在晶圆上,氧化物被蚀刻掉以显示新的扩散区域。制造特定集成电路所需的每个掩模(多达18个)都要重复这个过程。这里最重要的是每个掩模在晶圆表面上的精确对齐。如果偏差超过一微米(百万分之一米),整个晶圆片就会失效。在最后的扩散过程中,一层氧化物又在水面上生长起来。氧化层的大部分被留在晶圆上作为电绝缘体,只有很小的开口被蚀刻穿过氧化层以暴露电路接触区。为了连接这些区域,在整个表面沉积一层薄薄的金属(通常是铝)。

金属浸入电路接触区域,触摸硅。然后蚀刻大部分表面金属,留下电路元件之间的互连图案。最终层是“VAPOX”,或蒸汽沉积氧化物,一种保护IC免受污染和损坏的玻璃材料。它也被蚀刻蚀刻,但仅在“粘接垫”之上,稍后将附着线的正方形铝区域。

引用本文为:威廉安德森(SchoolWorkeHelper编辑组),“硅:元素,使用,事实”学校努力,2019年,//www.chadjarvis.com/silicon-element-uses-facts/

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