半导体,Part One Electronics,Unit 2 Semiconductor,Preparing for the text:,Technical terms: 1. integrated circuit (IC) 集成电路 2. N-type material N型材料 3. P-type material P型材料 4. forward bias 正向偏置 5. reverse bias 反向偏置 6. P-N junction P-N结 Questions for text discussion: Materials can usually be divided into three types, what are they? Conductor, semiconductor, insulator 2. Give some examples about semiconductor materials. Si, Ge 3. Describe the p-n junction electrical properties. see next page,After joining p-type and n-type semiconductors, electrons near the pn interface tend to diffuse into the p region. As electrons diffuse, they leave positively charged ions (donors) in the n region. Likewise, holes near the pn interface begin to diffuse into the n-type region, leaving fixed ions (acceptors) with negative charge. The regions nearby the pn interfaces lose their neutrality and become charged, forming the space charge region or depletion layer .,The main idea of this unit:,This unit mainly discusses the basic knowledge about “semiconductor”. Materials can usually be divided into conductor, semiconductor and nonconductor (2). Their electrical properties altered by the controlled addition of very small quantities of impurities such as boron or phosphorus.,1. circuit n.电路 A closed path followed or capable of being followed by an electric current. 电路：一个通过电流或可通过电流的封闭路径 2. substance n. (1) That which has mass and occupies space; matter. 物体：有质量及占据空间的东西；物质 (2) Material possessions; goods; wealth: 财产；物品；财富： a person of substance. 富有的人,New Words,3. insulator n. 绝缘体 (nonconductor) A material that insulates, especially a nonconductor of sound, heat, or electricity. 绝缘体：绝缘材料，特别是声、热、电的非导体 4. silicon n. 化 硅,5. electrical adj. 电的，电气的 6. conductivity n. 传导性，导电性 Electrical conductivity 电导性 7. switch (1) n. 开关 light switch (2) v. 切换 The office has switched from typewriters to word processors. 办公室已把打字机换成了文字处理器 8. perform vt. 履行,执行，表演 (1) perform ones contractual obligations. 履行合同规定的义务 (2) The theater group performed a three-act play. 剧团排演了一出三幕剧,9. Instruction n. 指示,指令，说明书 computer instruction 计算机指令 10. device n. 器件,装置，设备 machine device 机器设备 11. diode n. 二极管 An electronic device that restricts current flow chiefly to one direction. 二极管：将电流主要限制于一个方向流动的电子器件. 12. dope vt. 向内加物质 dope sugar into coffee 咖啡里加糖 13. property n. 性质，特性 a medicine with special properties. 具有特殊性能的药物,14. alter v. To change or make different; modify: 变更，更改 altered my will. 修改我的遗嘱15. boron n. 化 硼 16. phosphorus n. 化 磷 17. impurity n. 杂志，不纯 pure a. purity n. im-表示否定 18. junction n. 连接，结 The act or process of joining or the condition of being joined. 连接，接合：联结的行为、过程或被接合在一起的状态 PN junction 19. restrict vt. 限制，约束，限定 This test is restricted from chapter 1 to chapter 5. 这次考试内容限制在第一章到第五章。,Text,译:所有的集成电路都是由半导体制成的，半导体是一种导电性介于导体和绝缘体之间的物质。硅是最常用的半导体材料。因为半导体的导电性可以随所加的电压变化而变化，由半导体制作的晶体管可以作为告诉开关使用，它可以在几毫微秒（1秒的十亿分之一）的时间内开断电流。这一能力使计算机每秒可完成百万次以上的简单指令操作，迅速完成复杂的任务。,Phrases: integrated circuit; be made from; according to; apply to; act like.,各种半导体器件中最基础的是二极管，它是由N型半导体和P型半导体相结合所形成的PN结构成的。N型和P型指的是半导体材料已经掺入了杂质，通过控制加入的少量杂质如硼或磷可以改变半导体的电性能。 Phrases: quantity of; such as.,在二极管中，电流仅在一个方向流动：仅当P区比N区电位高时，电流才P区穿过PN结到N区。加在二极管上的满足这一条件的电压称为正向偏压，如图1所示。反之，称为反向偏压，且无电流通过。一个集成电路包括成千上万的PN结，每个PN结在电子电路元件中都起着特定的作用。合理的配置P区和N区可以限制电流在所需的路径流动，确保集成电路的正常工作。 Phrases: apply to; millions of.,Notes to the text: 1. Because the electrical conductivity of a semiconductor can change according to the voltage applied to it, transistors made from semiconductors act like tiny switches that turn electrical current on and off in just a few nanoseconds (billionths of a second). 因为半导体的导电性可以随所加的电压变化而变化，半导体制作的晶体管可以作为高速开关使用，它可以在几豪微妙（1秒的十亿致意）的时间内通断电流。 这里的because . according to the voltage applied to it, 为原 因状语从句，后面主句中的made from semiconductor 为分词 短语作定语，修饰transistors, 而主句中的that turn electrical current . Nanoseconds为that 引导的定语从句，修饰tiny switches.,2. The voltage applied to diode to create this condition is called the forward bias. 加到二极管上的满足这一条件的电压称为正向偏压。 这里的applied to create this condition为过去分词短语作定 语，修饰前面的voltage. 3. An integrated circuit contains millions of p-n junctions, each serving a specific purpose within the millions of electronic circuit elements. 一个集成电路包含成千上万的P-N结，每个结在电子电路 元件中起到特定作用。 这里each serving circuit elements为带逻辑主语的分词短 语，作伴随状语。,Exercises: 1. Translate the following phrases and expressions. (1) integrated circuit (2) the electrical conductivity of a semiconductor (3) P型材料的半导体 (4) 正向偏压 (5) to perform many millions of simple instructions each second 2. Match Column A with Column B. Column A Column B (1) insulator (a) a kind of material which does not allow electricity to pass through it (2) switch (b) an electronic device often used for amplifying voltage and current (3) transistor (c) a device which can stop and start the flow of electric current (4) semiconductor (d) an electric path which usually consists of a power supply ,wire, switch, a