专业英语2-第3讲-Chapter 3.4

Chapter 3 Processing Technology

3.1 Crystal growth and epitaxy晶体生长和外延

As discussed previously in Chapter 1, the two most important semiconductors for discrete分离的devices and integrated circuits are silicon and gallium镓arsenate砷酸盐.

正如之前在第一章所讨论的，对于分立器件和集成电路而言, 两种最重要的半导体是硅和砷化镓。

In this chapter we describe the common techniques for growing single crystals of these two semiconductors.

在本章, 我们描述生长这两种半导体单晶的常用技术。

The basic process flow is from starting materials to polished抛光wafer s.

基本流程是从原料到抛光片。

The starting materials (e.g., silicon dioxide for a silicon wafer) are chemically processed to form a high-purity polycrystalline多晶semiconductor from which single crystals are grown.

原材料(即，用于生长硅片的二氧化硅) 通过化学处理形成高纯度的多晶半导体以生长单晶。

di-ox-ide二-氧-化物

di-chlor-ide二-氯-化物

di-sulf-ide 二-硫-化物

poly crystal line 多晶

前缀poly-聚合、多, mulit-多single- 单

The single-crystal ingot s锭are shaped to define the diameter of material and saw ed into wafers.

定形后的单晶锭决定了材料的直径，并且被切成晶元。

These wafers are etch ed蚀刻and polished to provide smooth, specular surfaces on which devices will be made.

这些晶圆被蚀刻和抛光以得到光滑的镜面表面，器件将制造在其表面上。

A technology closely related to crystal growth involves the growth of single-crystal

semiconductor layers upon a single-crystal semiconductor substrate基片，衬底.

晶体生长密切相关的一个技术包括在单晶半导体基板上生长单晶半导体层(的技术)。

This is called epitaxy, from the Greek words epi (meaning “on”) and taxis (meaning “arrangement”).

这被称为外延，来源于希腊文字中的epi（意为“on”）及taxis（意为“安排”）。

The epitaxial process offers an important means of controlling the doping profiles剖面，详细资料so that device and circuit performances can be optimized优化.

外延工艺提供了控制掺杂分布，使设备和电路性能可以得到优化的重要手段。For example, a semiconductor layer with a relatively low doping concentration浓度can be grown epitaxially upon a substrate which contains the same type of dopant掺杂剂in a much higher concentration(e.g.,n-type silicon on an n+ -silicon substrate). 例如，一个相对较低的掺杂浓度的半导体外延层可以外延生长在一个掺杂类型相同但浓度更高的的基片上（例如，n型硅生长在n+ - Si衬底硅）。

In this way the series resistance 串联电阻associated with the substrate can be substantially reduced.

通过这种方式，与基板相关的串联电阻可以大幅地减少

Many novel device structures, especially for microwave and photonic devices, can be made by epitaxial processes.

许多新的元件结构，特别是微波和光子器件，可以通过外延法加工。

novel新颖的n. 小说

Later in this chapter we consider some important epitaxial growth techniques.

在本章后面，我们会介绍一些重要的外延生长技术。

3.2 Crystal Growth from the Melt从熔体生长晶体

There are basically two techniques for crystal growth from the melt (i.e., material in liquid form): the Czochralski techniques and the Bridgman technique.

有两种基本技术可以从熔体（即液态的材料）生长晶体：乔赫拉尔斯基法（也称为直拉法）和布里奇曼法(双温区生长法)。

A substantial percentage (-90%) of the silicon crystals for the semiconductor industry

are prepared by the Csochralski technique; virtually all the silicon used for fabrication integrated circuits is prepared by this technique.

一个相当大的比例（约90％）的半导体工业用的硅晶体由CZ法制备，几乎所有用于制造集成电路的硅都采用这种技术制备。

Most gallium arsenide, on the other hand, is grown by the Bridgman technique. However, the Czochralski technique is becoming more popular for the growth of large-diameter gallium arsenide.

大多数砷化镓，反过来，是布里奇曼技术生长。然而，使用Czochralski技术来生长大直径的砷化镓也越来越多（流行）。

gallium arsenide 砷化镓

arsen-ide 砷化物

arsenic 砷

arsenate砷酸

3.2.1 Starting materials 原料

The starting materials for silicon is a relatively pure form of sand (SiO2) called quartzite石英岩.

硅的原料是相对纯净的砂子（SiO2），称为石英岩（或硅石）。

This is placed in a furnace with various forms of carbon (coal, coke, and wood chips). While a number of reactions take place in the furnace, the overall reaction is SiC (solid) +SiO2(s) – Si(s) + SiC(g) +CO(g)

石英岩与各种形式的碳（煤，焦炭和木屑）一起放置在反应炉中。尽管反应炉中发生了很多反应，总反应是

SiC Silicon carbide 碳化硅

CO Carbon mono-x-ide 一氧化碳

This process produces metallurgical冶金–grade silicon with a purity of about 98%. Next, the silicon is pulverized粉碎and treated with hydrogen chloride (HCL) to form trichlorosilane (SiHCl3):

Si(solid) + 2HCL(gas) – SiHCl3(gas) +H2(gas)

这一过程产生冶金级，纯度约98％的硅。其次，硅被粉碎并和氯化氢（HCL）

反应以形成三氯氢硅：

Tri-chloro-silane 三-氯-硅烷

HCL Hydrogen chlor-ide氯化氢

The trichlorosilane is a liquid at room temperature (boiling point 32℃).

三氯氢硅在室温时是的液体（沸点为32℃）。

boiling point 沸点

melting point 熔点

Fractional部分的distillation蒸馏of the liquid removes the unwanted impurities.

通过精馏液体除去不需要的杂质。

distill v.蒸馏distil lation n. 蒸馏

The purified SiHCl3is then used in hydrogen reduction reaction to prepare the electronic-grade silicon (EGS)：

SiHCl3+ H2– Si + 3HCl

纯化后的SiHCl3通过氢还原反应可以制备电子级硅（EGS）：

This reaction takes place in a reactor containing a resistance-heated silicon rod, which serves as the nucleation核point for deposition of silicon.

这种反应发生在一个含有电阻加热的硅棒的反应炉中，硅棒可作为硅沉积的成核点。

The EGS, a polycrystalline material of high purity, is the raw material used to prepare device quality single-crystal silicon.

高纯度多晶硅材料，是用来制备器件级单晶硅的原始材料。

Pure EGS generally has impurity concentrations in the part-per-billion range.

纯电子级硅的杂质浓度范围通常为亿分之一。

The starting materials for gallium arsenate are the elemental, chemically pure gallium and arsenic砷, which are used for the synthesis of polycrystalline gallium arsenide.

砷化镓的原材料是，化学纯镓和砷，用于合成多晶镓砷化物。

arsenate【化】砷酸盐(或酯) arsenide【化】砷化物

Because gallium arsenide is a combination化合物of two materials, its behavior is quite different from that of a single materials such a silicon.

由于砷化镓是两种材料的化合物，它的特性与例如硅这样的单一材料是完全不同的。

第二讲

The behavior of a combination can be described by a phase diagram图表. A phase is a state (e.g., solid, liquid, or gaseous) in which a material may exist.

化合物的表现可以用一个相图来描述。一个相是一种状态（如固态，液态或气态），一种物质可能存在于其中。

A phase diagram shows the relationship between two components (e.g., gallium and arsenic) as a function of temperature.

相图显示了两个成份（例如，镓和砷）随温度的函数关系。

Unlike silicon, which has relatively low vapor pressure at its melting point (10-6 atm at 1240℃), both gallium and arsenic have much higher vapor pressure at the melting point of gallium arsenide (1238℃).

不同于硅，在其熔点具有相对较低的蒸汽压（1240℃时为10-6大气压），镓和砷在砷化镓的熔点（1238℃）具有更高的蒸气压力。

In its vapor phase, arsenic has As2 and As4 as its major species.

在气相时，砷为主要以AS2和AS4分子的形式存在。

The vapor pressure curves for gallium arsenide melt, and the solid curves are for gallium-rich melt, more arsenic (As2 and As4) will be vaporized from the arsenic-rich melt, thus resulting in a higher vapor pressure.

气体压力曲线对应于砷化镓熔体，固体曲线对应于富镓熔体。更多的砷（As2和As4）将从富砷的熔体中蒸发，从而造成更高的蒸汽压。

A similar argument can explain the higher vapor pressure of gallium in a gallium-rich melt.

类似的观点可以解释富镓熔体中镓的蒸气压较高。

Note that long before the melting point is reached, the surface layers of liquid gallium arsenide may decompose into gallium and arsenic.

需要注意，在达到熔点之前，镓砷化液体的表面层可能分解成镓和砷。

Since the vapor pressure of gallium and arsenic are quite different, there is a preferential loss of the more volatile arsenic species, and the liquid becomes gallium

rich.

由于镓和砷的蒸汽压力是有很大差别，挥发性较强的砷将会优先损失，液体中镓变得丰富。

To synthesize gallium arsenide, an evacuate d, seal ed quartz tube system with a two-temperature furnace is commonly used.

通常用一个具有双温区的高温炉及抽真空的密封石英管系统来合成砷化镓。The high-purity arsenic is placed in a graphite boat and heated to 610 to 620 ℃, while the high-purity gallium is placed in another graphite boat and heated to slightly above the gallium arsenide melting temperature (1240 to 1 260 ℃).

高纯度砷被放置在一个石墨舟中，加热到610至620℃，而高纯度镓是摆在另一石墨舟中，加热到略高于砷化镓的熔融温度（1240?1 260℃）

Under these conditions, an overpressure of arsenic is established (1) to cause the transport of arsenic vapor to the gallium melt, converting it into gallium arsenic vapor to the gallium melt, converting it into gallium arsenide, and (2) to prevent decomposition of the gallium arsenide while it is being formed in the furnace.

在这种条件下，形成砷的过压（1）使砷气体输送到镓熔体，使之从砷化镓气体转化到镓熔体，使之转化为砷化镓，（2）防止砷化镓在（化应炉中）合成过程中分解。

When the melt cools, a high-purity polycrystalline gallium arsenide results. This serves as the raw material to grow single-crystal gallium arsenide.

当熔体冷却，可得到高纯度多晶硅砷化镓。这可作为生长单晶砷化镓的原料。

3.2.2 The Czohcralski Technique

The Czochralski technique for silicon crystal growth uses an apparatus called a puller提拉机，拉单晶机, as shown in Figure 3-1.

CZ法生长硅晶体生长使用的仪器称为拉单晶机，如图3-1所示。

The puller has three main components: (1) a furnace, which includes a fused-silica (SiO2) crucible坩埚, a graphite susceptor基座, a rotation mechanism (clockwise as shown), a heating element, and a power supply;

拉单晶机有三个主要部分组成：（1）反应炉，其中包括熔融石英（SiO2）的坩埚，石墨基座，旋转机械（顺时针方向如图所示），加热元件，以及电源;

(2) a crystal-pulling mechanism, which includes a seed holder支架and a rotation mechanism (counter-clockwise); and (3) an ambient气氛control, which includes a gas source (such as argon), a flow control, and an exhaust排气system.

（2）拉单晶机，其中包括晶种支架和旋转装置（逆时针）和（3）气氛控制，其中包括气源（如氩气），流量控制，和排气系统。

In addition, the puller has an overall microprocessor-based control system to control process parameters such as temperature, crystal diameter, pull rate, and rotation speeds, as well as to permit programmed steps.

此外，提拉机有一个基于微处理器的总控制系统来控制工艺参数，如温度，晶体直径，拉伸速度和旋转速度等，同时可对工艺过程进行编程控制。

Also, various sensors and feedback loops allow the control system to respond automatically, thereby reducing operator intervention干预.

此外，各种传感器和反馈回路使控制系统自动响应，从而减少操作人员干预。

In the crystal-growing process, polycrystalline silicon is placed in the crucible and the furnace is heated above the melting temperature of silicon.

在晶体生长过程中，多晶硅是放置在坩埚中并且反应炉加热至硅的熔化温度以上。

A suitably oriented seed crystal (e.g., <111>) is suspended over the crucible in a seed holder. The seed is inserted into the melt. Part of it melts but the tip of the remaining seed crystal still touches the liquid surface. It is then slowly withdrawn.

一个合适取向的晶种（如<111>）装于支架中悬浮在坩埚上方。晶种被插入到融体中。如果部分融化，但剩余的晶体仍然接触液体表面。然后慢慢地撤回。Progressive freezing at the solid-liquid interface yields a large, single crystal. A typical pull rate is a few millimeters per minute.

固液交界面逐步冷却后得到大块单晶。一个典型的拉单晶机的提拉速度是每分钟几毫米。

For Czochralski growth of gallium arsenide, the basic puller is identical to that for silicon.

对于直拉砷化镓生长，拉单晶机和生长硅的基本一样。

However, to prevent decomposition of the melt during crystal growth, a liquid

encapsulation method is employed.

然而，为了防止晶体生长过程中融体分解，采用了液态密封法。

The liquid encapsulate is a molten boron trioxide (B2O3) layer about 1 cm thick.

密封的液体是用约1厘米厚的熔融三氧化二硼（B2O3）。

Molten boron trioxide is inert to gallium arsenide at the growth temperature.

熔融三氧化二硼镓在砷化镓的生长温度时加入。

The layer adheres to the gallium arsenide surface and serves as a cap to cover the melt.

该层粘附在砷化镓表面，向一个罩子一样覆盖在熔体上。

This cap prevents decomposition of the gallium arsenide as long as the pressure on its surface is higher than 1 atm (760 Torr).

覆盖在熔体上的罩子可以防止砷化镓在表面压力大于1大气压（760托）时发生分解。

Since boron trioxide can dissolve silicon dioxide, the fused-silica crucible is replaced with a graphite crucible.

由于三氧化二硼能溶解二氧化硅，采用石墨坩埚取代了熔融石英坩埚。

3.3 Vapor-Phase Epitaxy

In an epitaxial process, the substrate wafer acts as a seed crystal.

在一个外延的过程中，晶元衬底充当籽晶。

Epitaxial processes are differentiated from the melt growth processes (described in section 3.1) in that the epitaxial layer can be grown at a temperature substantially below the melting point (typically 30% to 50% lower).

外延过程与熔体生长过程是有区别的（在3.1节中所述），主要在于外延层可以在远低于熔点的温度下生长（一般可低30％至50％）。

Among various epitaxial processes, vapor phase epitaxy (VPE) is by far the most important for silicon devices.

在各种外延工艺中，气相外延是迄今为止最重要的硅器件（加工工艺）。

VPE is also important for gallium arsenide, but other epitaxial processes (e.g., molecular-beam epitaxy) can provide certain advantages not obtainable from VPE.

气相外延对砷化镓而言也是很重要的，但其他（例如，分子束外延）外延过程也

具有一些气相外延所没有的优势

Note that the geometric shape of the susceptor provides the name for the reactor: horizontal, pancake, and barrel susceptors --- all made from graphite blocks.

请注意，基座的几何形状提供了反应器的名称：水平，饼状，和桶形基座，全部由石墨块组成。

Susceptors in the epitaxial reactors are analogous to crucibles in the crystal growing furnaces.

在外延反应堆中，基座类似于晶体生长炉中的坩埚。

Not only do they mechanically support the wafer, but in induction－heated reactors they also serve as the source of thermal energy for the reaction.

Not only do they mechanically support the wafer 倒装句

but they also serve as the source of thermal energy for the reaction in induction－heated reactors.

基座不仅为晶圆片提供机械支持，此外，在感应加热反应堆中，他们也作为反应的热能来源。

Four silicon sources have been used for vapor phase epitaxial growth. They are silicon tetrachloride (SiCl4), dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), and silane (SiH4).

课本中dichlorosil i ane 应改为dichlorosilane

四种硅源已用于气相外延生长。分别是四氯化硅（SiCl4），二氯氢硅（SiH2Cl2），三氯氢硅（SiHCl3），和硅烷（SiH4）。

silane 硅烷

chloro－silane 氯代硅烷，一氯硅烷

di－chloro－silane 二氯硅烷，二氯氢硅

tri－chloro－silane 三氯硅烷，三氯氢硅

silicon tetra－chloride 四氯化硅

tetra- 四（前缀）

Silicon tetrachloride has been the most studied and has the widest industrial use.

四氯化硅是研究最多，并具有广泛的工业用途。

The typical reaction temperature is 1200℃. Other silicon sources are used because of lower reaction temperatures.

（四氯化硅的）典型的反应温度为1200℃。如果反应温度较低。需要使用其他的硅源

The substitution of a hydrogen atom for each chlorine atom from silicon tetrachloride permits about a 50℃ reduction in the reaction temperature.

对于四氯化硅，每用一个氢原子取代一个氯原子，可以使在反应温度减少大约50℃。

The overall reaction of silicon tetrachloride that results in the growth of silicon layers is

SiCl4(gas)+2H2(gas)←→Si(solid)+4HCl(gas) (3-4)

使用四氯化硅生长硅层的总反应是

An additional competing reaction is taking place along with that given in Eq.3-4: SiCl4(gas)+ Si(solid)←→2 SiCl2(solid) (3-5)

与反应3－4同时发生的反应还有：

As a result, if the silicon tetrachloride concentration is too high, etching rather than growth of silicon will take place.

因此，如果四氯化硅的浓度太高，硅将会被蚀刻，而不是生长。

rather than 而不是

The effect of the concentration of silicon tetrachloride in the gas on the reaction is shown, where the mole fraction is defined as the ration of the number of molecules of a given species to the total number of molecules.

这显示了（反应）气体中四氯化硅浓度对反应的影响，由此，摩尔分数被定义为：指定的反应分子数与分子总数的比值。

第3讲

Note that initially the growth rate increases linearly with increasing concentration of silicon tetrachloride.

特别是，最初的生长速度随四氯化硅浓度的提高而线性提高。

As the concentration of silicon tetrachloride is increased, a maximum growth rate is reaches.

随着四氯化硅浓度的增加，达到最大的生长速度。

Beyond that, the growth rate starts to decrease, and eventually etching of the silicon will occur. Silicon is usually grown in the low concentration region.

超过之后，生长速度开始下降，最终硅的蚀刻将会发生。硅是通常生长在低浓度区。

The reaction of Eq. 3-4 is reversible, that is, it can take place in either direction. If the carrier gas entering the reactor contains hydrochloric acid, removal or etching will take place.

方程3-4的反应是可逆的，也就是说，它可以在任何一个方向进行。如果进入反应器内的运载气体含有盐酸，消除或蚀刻将进行。

Actually, this etching operation is used for in-situ （拉丁语：原位）cleaning of the silicon wafer prior to epitaxial growth.

其实，这种蚀刻操作被用于在外延生长之前对硅片进行原位清洗。

The dopant掺杂剂is introduced at the same time as the silicon tetrachloride during epitaxial growth.

掺杂剂在四氯化硅外延生长过程的同时被引入。

Gaseous diborane (B2H6) is used as the p-type dopant, while phosphine (PH3) and arsine (AsH3) are used as n-type dopants.

气态乙硼烷（B2H6）作为p型掺杂，而磷化氢（PH3）和砷化氢（AsH3）是作为n型掺杂剂使用。

Gas mixtures are ordinarily used with hydrogen as the diluent to allow reasonable control of flow rates for the desired doping concentration.

混合气体通常加入氢气，用作稀释剂，以便合理控制的流量从而获得所需的掺杂浓度。

The dopant chemistry for arsine is illustrated in a figure, which shows arsine being adsorbed on the surface, decomposing, and being incorporated（合并）into the growing layer.

对于砷的掺杂化学（过程或反应）可以用一个图来说明，它显示砷化氢被吸附在表面，分解，与被并入到生长层。

To give these adsorbed atoms sufficient mobility for finding their proper positions

within the crystal lattice, epitaxial growth needs relatively high temperatures.

为了让这些被吸附的原子具有充足的流动性，从而可以在晶格上寻找到适当的位置，外延生长需要相对较高的温度。

Since gallium arsenide decomposes into gallium and arsenic upon evaporation, its direct transport in the vapor phase is not possible.

由于砷化镓会被蒸发分解成砷和镓，其在气相中直接运输是不可能的。

One approach is the use of As4 for the arsenic component and gallium chloride (GaCl3) for the gallium component. The overall reaction leading to epitaxial growth of gallium arsenide is

As4+4GaCl3+6H2→4GaAs+12HCl (3-6)

一种方法是用As4的做为砷源，氯化镓（GaCl3）做为Ga源。外延生长砷化镓的总反应是：

The As4 is generated by thermal decomposition of arsine (AsH3):

4AsH3→As4+6H2(3-6a)

As4由氢化砷热分解产生

And the gallium chloride is generated by the reaction

6HCl +2Ga→2GaCl3+3H2(3-6b)

氯化镓由以下反应生成

The reactants are introduced into a reactor with a carrier gas。

反应物通过运载气体引入到反应室。

The gallium arsenide wafers are typically held within the 650 to 850℃temperature range.

在砷化镓晶元片通常保持在650?850℃温度范围。

There must be sufficient arsenic overpressure to prevent thermal decomposition of the substrate and the growing layer.

必须有足够的砷超压，以防止衬底和生长层的热分解。

Another approach is the MOCVD (metal organic chemical vapor deposition) which uses metalorganic compounds such as trimethylgallium Ga(CH3)3.

另一种方法是的MOCVD（有机金属化学气相沉积）法，此法使用有机金属化合

物，例如三甲基镓。

One can use trimethylgallium for the gallium component. Both chemicals can be transpired（发散，泄漏）in vapor form into the reactor. The overall reaction is As4H3 + Ga(C H3)3→gallium arsenide + 3CH4

人们可以用三甲基镓作为镓源。这两种化学物质都可以以气相输送进入反应器。总的反应是

During epitaxy the doping of gallium arsenide is done by the introduction of dopants in vapor form.

在砷化镓的外延中，从气相中引入掺杂剂进行掺杂。

The hydrides of sulfur and selenium or tetramethyltin四甲基锡are used for n-type doping; and chromyl chloride is used to dope chromium onto gallium arsenide to form semi-insulation layers.

硫和硒的氢化物或四甲基锡用于n型掺杂;氯化铬酰用于掺杂铬进入到砷化镓以形成半绝缘层。

tetra-methyl-tin 四-甲基-锡

As with silicon epitaxial growth, an in-situ etching is done to remove any contaminants prior to the growth.

随着硅外延生长，在原位进行蚀刻，以生长前的消除外延生长前的污染物。

3.4 Oxidation and Film Deposition 氧化和薄膜沉积

To fabricate discrete devices and integrated circuits we use many different kinds of thin film.

为了制作分立器件和集成电路，我们使用许多不同种类的薄膜。

We can classify thin films into four groups: thermal oxides, dielectric layers, polycrystalline silicon, and metal films.

我们可以将薄膜分为四组：热氧化物，介电层，多晶硅，金属薄膜。

dielectric 不导电的，介电的

dielectric constant 介电常数

Figure 3-2 shows a schematic view 示意图of a conventional silicon n-channel MOSFET that uses all four groups of film.

schematic n.概要议程adj. 概要的

MOSFET metal–oxide–semiconductor field-effect transistor金属氧化物半导体场效应晶体管

图3-2显示了一个使用了所有这四种薄膜的传统硅N沟道MOSFET的示意图。

The first important thin film from the thermal oxide group is the gate oxide layer under which a conduction channel can be formed between the source and the drain.

第一个来自热氧化组的重要薄膜，是栅氧化层，在其下方一个传导通道可在源和漏极之间形成。

A related layer is the field oxide, which provides isolation from other device structures.

一个相关的层是场氧化层，它提供了从其他设备结构隔离。（意译：它隔离了其他设备结构）

Both gate and field oxides generally are grown by a thermal oxidation process because only thermal oxidation can provide the highest-quality oxides having the lowest interface trap densities.

栅极和场氧化物层都是通过热氧化工艺生长，因为只有热氧化法才能提供最高质量的，具有最低的界面陷阱密度的氧化物。

Dielectric layers （such as the deposited silicon dioxide and silicon nitride）are used for insulation between conducting layers, for diffusion and ion implantation masks掩蔽层, for capping doped films to prevent the loss of dopants, and for passivation钝化层to protect devices from impurities, moisture湿气, and scratches.

绝缘层/介电层，例如沉积的二氧化硅和氮化硅，可用作导电层间的绝缘层，用于扩散和离子注入的掩蔽层，用于覆盖掺杂的薄膜以防止掺杂损失，用作钝化层保护器件不受杂质，湿气和划痕等的影响

沉积的二氧化硅，氮化硅等电解质层做为导电层之间的绝缘层，可作为扩散和离子注入时的掩蔽层，也可作为掺杂薄膜之上覆盖层以防止掺杂损失。同时可作为钝化层防止器件受外界杂质、潮湿空气，划痕等的影响。

Polycrystalline silicon, usually referred to as polysilicon, is used as gate electrode material in MOS devices, as a conductive material for devices with shallow junctions.

多晶硅通常写为polysilicon，它对于浅结器件来说是导电材料，在MOS型器件中常用做栅极材料。

Metal films such as aluminum and silicides are used to form low-resistance interconnections, ohmic contacts to n+_, p+_, and polysilicon layers, and rectifying 纠正metal-semiconductor barriers.

金属薄膜，例如铝和硅化物，用来形成低电阻的互连，n+_, p+_，和多晶硅层的欧姆接触，调节金属半导体接触势垒。

When a film is formed (e.g., by oxidation or chemical vapor deposition), device features generally are defined by lithographic and etching processes.

当一层薄膜形成后（通过氧化法或化学气相沉积法），器件功能通常由光刻和蚀刻工艺决定。

Each film must both perform its intended function and be compatible with the overall processing sequence, that is, the film must withstand the required chemical treatment and thermal cycle while its structure remains stable.

每一层薄膜都必须执行其预设功能，并与整体处理顺序兼容，也就是说，薄膜必须经受必要的化学处理和热循环，而其结构保持稳定。

In this chapter we consider the formation and characteristics of these films.

在这一章中，我们讨论这些薄膜的形成和特性。