10第十讲 MOS(1)

(P144) As for the transport in the semiconductor bulk, the velocity of surface carriers saturates for high electric fields in the direction of the current flow (longitudinal field). P146 L1 Velocity saturation will occur when the horizontal electric field is approximately 104 V/cm.
Physics of Semiconductor Devices (双语)
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MOSFET
Metal-Oxide-Semiconductor Field-Effect Transistor MOSFET is a device used for amplifying or switching electronic signals. In MOSFET, a voltage on the oxide-insulated gate electrode can induce a conducting channel between the two other contacts called source and drain. The channel can be of n-type or p-type, and is accordingly called nMOSFET or pMOSFET.oxide（场氧化层）
thick
Compare with bipolar transistor

The first MOSFET suitable for commercial use did not appear until the 1960s. In the four decades since that time, MOSFET have displaced bipolar transistors to become the most extensively used active solid-state devices. MOSFET have several advantages over bipolar transistors for digital circuits, an application area that grew exponentially over this same time period. MOSFET are built with basically simpler fabrication technologies than are bipolar transistors and it is easier to build them in dense arrays. They also typically consume less power than do bipolar integrated circuits, especially at lower frequencies. Because of their simpler fabrication, higher density, and lower power, MOSFET are widely used in memory circuits, totally displacing bipolar memories.
括号进一步给出前面叙述内容的定义，注意翻译以及译文
中括号的位置，不一定像原文那样跟在inversion layer后面 。

在MOS晶体管中，载流子在半导体中与氧化层界面附近流动 ，而界面处附加的散射机构将会使反型层中载流子的迁移率 （又称为表面迁移率）降低至体迁移率的一半。
We have pointed out that when the source and drain depletion regions are a substantial fraction of the channel length, short-channel effects start to occur. In extreme cases when the sum of these depletion widths approaches the channel length ys+yd=L, more-serious effects will happen. This condition is commonly called punch-through. The net result is a large leakage current between the source and drain, and that this current is a strong function of the drain bias. The origin of punch-through is the lowering of the barrier near the source, commonly referred to as DIBL (drain-induced barrier lowering). When the drain is close to the source, the drain bias can influence the barrier at the source end, such that the channel carrier concentration at that location is no longer fixed. This is demonstrated by the energy bands along the semiconductor surface, shown in Figure 14.2 . The subthreshold current is most sensitive to DIBL, and when barrier lowering occurs, one can most easily detect it by measuring the dependence of subthreshold current on VD. In contrast, subthreshold current is independent of the drain voltage in long-channel devices.
“纵向”对应沟道方向（y方向），“横向”对应x方向。



说明: 括号内容起补充说明作用，直接翻译即可。 Transverse：extending across something, at right angles to the long axis (横向的) Longitudinal：extending in a direction parallel with a thing’s length (纵向的) 结论 “横向”不一定是“水平方向” 对于MOSFET而言,沿沟道方向应该是 “纵向”, 而垂直于沟 道方向应该是 “横向” 为避免产生误解，翻译时最好给出方向的具体含义 也可以按照坐标分别翻译为x方向, y方向 翻译: 沟道区的二维电势分布同时取决于垂直于沟道方向的电 场Ex （由栅压和衬底偏置控制）以及沿着沟道方向的电场Ey （由漏极偏置控制） 。
Gate dielectric（栅介质）
Silicon
dioxide, high-k dielectric
Gate electrode（栅电极）

metal, polysilicon implantation，heavily doped oxide
Source drain reigon（源漏区）



Transverse shrinkage varying along width direction and longitudinal shrinkage varying along length direction of the plate are investigated.

研究了沿板宽方向变化的横向收缩及沿板长方向变 化的纵向收缩。 Paper orientation of document is selected to be portrait (normal) or landscape (sidewise). 纸张方向可以选择为竖或横

MOSFET have several advantages over bipolar transistors for digital circuits, an application area that grew exponentially over this same time period. 提示：an application area that……为digital circuits 的同位语，起补充说明的作用； grew exponentially不一定直译为“指数增长”， 可以意译为“发展迅速” 全句可翻译为：同一时期，数字电路发展迅速， 与双极晶体管相比，MOSFET在数字电路应用中 具有很多优点。


和方向相关的例句： (P145) The mobility depends also on the doping, and on the electric field component perpendicular to the current flow (transversal field)
MOS System
Fig. 13.2 The energy-band diagram of the MOS capacitor with a p-type substrate for (a) a negative gate bias, (b) a moderate positive gate bias and (c) a “large” positive gate bias.