1-1 Introduction to Microelectronics

The exploring of space and the development of earth satellites has increased the importance of reducing the size and weight of electronic circuits. Also, even though electricity flows quite rapidly in computers the time delay of the signal in the interconnections between electronic components is an important consideration. If the interconnections are reduced in size, a computer can perform operations at a faster speed.

Microelectronics involves the miniaturization of regular electronic circuits. A complete electronic circuit, an operational amplifier for example, which contains large numbers of individual interconnected components, such as diodes resistors, transistors, etc. may be formed on a very small single substrate. The complete miniaturized circuit is then called an integrated circuit.

Integrated circuits are small, light, rugged, and reliable. They require less power and lower voltages than equivalent macroscopic circuits; consequently they operate at lower temperatures, and individual components may be close together without exceeding the operating temperature limit. Relatively little stray capacitance and short time delays are produced because of the short interconnections between the individual components in IC. Maintenance is simplified because if a component of the IC fails the complete IC is usually replaced. Mass production techniques of plane technology have reduced the cost of many IC so that they are almost as inexpensive as a single transistor. Eventually most conventional circuits will be replaced by IC.

There are two types of basic integrated circuit: monolithic integrated circuit and the thin or thick film. Monolithic IC are constructed in a single substrate of single crystal semiconductor, usually silicon. Thin or thick films IC are formed on the surface of an insulating material such as glass or a ceramic. Hybrid IC contains more than single substrate, the term hybrid is also applied to combinations of monolithic and thin or thick film IC.

Integrated circuits are also classified according to their functions. Digital or logical IC are used as switches, they are either on or off. In computers the on and off states correspond to 0 or 1. Other IC is called linear or analog IC.[1] Integrated circuits can be produced using either bipolar or unique polar transistors. Field effect transistors (FET) have advantages over bipolar transistors in many cases however. They are relatively high-impedance devices, with a corresponding reduction in current and power dissipation, and yet have high power gain. The reduction in power dissipation is particularly important where a complex circuit is to be concentrated into a small space. The problem of extracting the heat generated in the circuit may then be a difficult one.[2] The form of construction of the FET, and particularly the MOSFET, also lends itself well to integrated circuit fabrication, and enables resistors and capacitors to be included readily in the integrated circuit.

Most electronic circuits are composed of active devices, e.g. transistors and diodes, together with resistors (for bias, collector load, impedance transformation, etc.) and capacitors (e.g. for coupling ac signals while blocking dc supplies). Each of these elements can be produced in a form suitable for integrated circuit inclusion within limitations, e.g. capacitance values must not be too large. Some elements are difficult to produce in a suitable form, e.g. inductive elements, or large capacitors. Usually some alternative circuit form can be devised that dispenses with the requirement. Otherwise they must be included as an external lumped element.

NOTES

[1]Integrated circuits are also classified according to their functions．Digital or logical IC are used as switches，they are either on or off. In computers the on and off states correspond to 0 or l．Other IC is called linear or analog IC．

也可根据其功能不同对集成电路进行分类。数字或者逻辑IC通常用作开关，表示接通或关断。在计算机中，接通和关断状态分别对应’0’或’1’。另一种IC被称为线性或模拟IC。

[2] The reduction in power dissipation is particularly important where a complex circuit is to be concentrated into a small space. The problem of extracting the heat generated in the circuit may then be a difficult one．

在需要将一个复杂的电子线路集成到一小块的问题中，减小功率损耗是非常重要的。要释放集成电路工作时产生的热量是一个难以解决的问题。

同学们知道存储卡、U盘是怎么生产的吗？来看一下下面这个视频吧！

学习了Unit1 之后，Intel的这则广告是不是能看懂了呢？

晶圆如何由沙子制造而成？来看一下这个视频吧！