半導(dǎo)體外文翻譯

1、<p><b>　　附 錄</b></p><p>　　附錄A:外文資料翻譯—原文部分</p><p>　　Semiconductor</p><p>　　A semiconductor is a solid material that has electrical conductivity between those of

2、 a conductor and an insulator; it can vary over that wide range either permanently or dynamically.[1]</p><p>　　Semiconductors are important in electronic technology. Semiconductor devices, electronic compone

3、nts made of semiconductor materials, are essential in modern consumer electronics, including computers, mobile phones, and digital audio players. Silicon is used to create most semiconductors commercially, but dozens of

4、other materials are used.</p><p>　　Bragg reflection in a diffuse lattice</p><p>　　A second way starts with free electrons waves. When fading in an electrostatic potential due to the cores, due t

5、o Bragg reflection some waves are reflected and cannot penetrate the bulk, that is a band gap opens. In this description it is not clear, while the number of electrons fills up exactly all states below the gap.</p>

6、<p>　　Energy level splitting due to spin state Pauli exclusion</p><p>　　A third description starts with two atoms. The split states form a covalent bond where two electrons with spin up and spin down

7、are mostly in between the two atoms. Adding more atoms now is supposed not to lead to splitting, but to more bonds. This is the way silicon is typically drawn. The band gap is now formed by lifting one electron from the

8、lower electron level into the upper level. This level is known to be anti-bonding, but bulk silicon has not been seen to lose atoms as easy as electrons</p><p>　　Energy bands and electrical conduction</p&

9、gt;<p>　　Like in other solids, the electrons in semiconductors can have energies only within certain bands (ie. ranges of levels of energy) between the energy of the ground state, corresponding to electrons tightl

10、y bound to the atomic nuclei of the material, and the free electron energy, which is the energy required for an electron to escape entirely from the material. The energy bands each correspond to a large number of discret

11、e quantum states of the electrons, and most of the states with low energy (c</p><p>　　The ease with which electrons in a semiconductor can be excited from the valence band to the conduction band depends on t

12、he band gap between the bands, and it is the size of this energy bandgap that serves as an arbitrary dividing line (roughly 4 eV) between semiconductors and insulators.</p><p>　　In the picture of covalent bo

13、nds, an electron moves by hopping to a neighboring bond. Because of the Pauli exclusion principle it has to be lifted into the higher anti-bonding state of that bond. In the picture of delocalized states, for example in

14、one dimension that is in a wire, for every energy there is a state with electrons flowing in one direction and one state for the electrons flowing in the other. For a net current to flow some more states for one directio

15、n than for the other direction </p><p>　　Electrons excited to the conduction band also leave behind electron holes, or unoccupied states in the valence band. Both the conduction band electrons and the valenc

16、e band holes contribute to electrical conductivity. The holes themselves don't actually move, but a neighboring electron can move to fill the hole, leaving a hole at the place it has just come from, and in this way t

17、he holes appear to move, and the holes behave as if they were actual positively charged particles.</p><p>　　One covalent bond between neighboring atoms in the solid is ten times stronger than the binding of

18、the single electron to the atom, so freeing the electron does not imply destruction of the crystal structure.</p><p>　　Holes: electron absence as a charge carrier</p><p>　　The notion of holes, w

19、hich was introduced for semiconductors, can also be applied to metals, where the Fermi level lies within the conduction band. With most metals the Hall effect reveals electrons to be the charge carriers, but some metals

20、have a mostly filled conduction band, and the Hall effect reveals positive charge carriers, which are not the ion-cores, but holes. Contrast this to some conductors like solutions of salts, or plasma. In the case of a me

21、tal, only a small amount of energy is </p><p>　　Fermi-Dirac distribution. States with energy ε below the Fermi energy, here μ, have higher probability n to be occupied, and those above are less likely to be

22、occupied. Smearing of the distribution increases with temperature.</p><p>　　The energy distribution of the electrons determines which of the states are filled and which are empty. This distribution is descri

23、bed by Fermi-Dirac statistics. The distribution is characterized by the temperature of the electrons, and the Fermi energy or Fermi level. Under absolute zero conditions the Fermi energy can be thought of as the energy u

24、p to which available electron states are occupied. At higher temperatures, the Fermi energy is the energy at which the probability of a state being o</p><p>　　The dependence of the electron energy distributi

25、on on temperature also explains why the conductivity of a semiconductor has a strong temperature dependency, as a semiconductor operating at lower temperatures will have fewer available free electrons and holes able to d

26、o the work.</p><p>　　Energy–momentum dispersion</p><p>　　In the preceding description an important fact is ignored for the sake of simplicity: the dispersion of the energy. The reason that the e

27、nergies of the states are broadened into a band is that the energy depends on the value of the wave vector, or k-vector, of the electron. The k-vector, in quantum mechanics, is the representation of the momentum of a par

28、ticle.</p><p>　　The dispersion relationship determines the effective mass, m * , of electrons or holes in the semiconductor, according to the formula:</p><p>　　The effective mass is important as

29、 it affects many of the electrical properties of the semiconductor, such as the electron or hole mobility, which in turn influences the diffusivity of the charge carriers and the electrical conductivity of the semiconduc

30、tor.</p><p>　　Typically the effective mass of electrons and holes are different. This affects the relative performance of p-channel and n-channel IGFETs, for example (Muller & Kamins 1986:427).</p>

31、<p>　　The top of the valence band and the bottom of the conduction band might not occur at that same value of k. Materials with this situation, such as silicon and germanium, are known as indirect bandgap material

32、s. Materials in which the band extrema are aligned in k, for example gallium arsenide, are called direct bandgap semiconductors. Direct gap semiconductors are particularly important in optoelectronics because they are mu

33、ch more efficient as light emitters than indirect gap materials.</p><p>　　Carrier generation and recombination</p><p>　　When ionizing radiation strikes a semiconductor, it may excite an electron

34、 out of its energy level and consequently leave a hole. This process is known as electron–hole pair generation. Electron-hole pairs are constantly generated from thermal energy as well, in the absence of any external ene

35、rgy source.</p><p>　　Electron-hole pairs are also apt to recombine. Conservation of energy demands that these recombination events, in which an electron loses an amount of energy larger than the band gap, be

36、 accompanied by the emission of thermal energy (in the form of phonons) or radiation (in the form of photons).</p><p>　　In some states, the generation and recombination of electron–hole pairs are in equipois

37、e. The number of electron-hole pairs in the steady state at a given temperature is determined by quantum statistical mechanics. The precise quantum mechanical mechanisms of generation and recombination are governed by co

38、nservation of energy and conservation of momentum.</p><p>　　As the probability that electrons and holes meet together is proportional to the product of their amounts, the product is in steady state nearly co

39、nstant at a given temperature, providing that there is no significant electric field (which might "flush" carriers of both types, or move them from neighbour regions containing more of them to meet together) or

40、 externally driven pair generation. The product is a function of the temperature, as the probability of getting enough thermal energy to produc</p><p>　　The probability of meeting is increased by carrier tra

41、ps – impurities or dislocations which can trap an electron or hole and hold it until a pair is completed. Such carrier traps are sometimes purposely added to reduce the time needed to reach the steady state.</p>&

42、lt;p><b>　　Doping</b></p><p>　　The property of semiconductors that makes them most useful for constructing electronic devices is that their conductivity may easily be modified by introducing im

43、purities into their crystal lattice. The process of adding controlled impurities to a semiconductor is known as doping. The amount of impurity, or dopant, added to an intrinsic (pure) semiconductor varies its level of co

44、nductivity. Doped semiconductors are often referred to as extrinsic.</p><p><b>　　Dopants</b></p><p>　　The materials chosen as suitable dopants depend on the atomic properties of both

45、 the dopant and the material to be doped. In general, dopants that produce the desired controlled changes are classified as either electron acceptors or donors. A donor atom that activates (that is, becomes incorporated

46、into the crystal lattice) donates weakly-bound valence electrons to the material, creating excess negative charge carriers. These weakly-bound electrons can move about in the crystal lattice relativel</p><p>

47、;　　For example, the pure semiconductor silicon has four valence electrons. In silicon, the most common dopants are IUPAC group 13 (commonly known as group III) and group 15 (commonly known as group V) elements. Group 13

48、elements all contain three valence electrons, causing them to function as acceptors when used to dope silicon. Group 15 elements have five valence electrons, which allows them to act as a donor. Therefore, a silicon crys

49、tal doped with boron creates a p-type semiconductor whereas one</p><p>　　Carrier concentration</p><p>　　The concentration of dopant introduced to an intrinsic semiconductor determines its concen

50、tration and indirectly affects many of its electrical properties. The most important factor that doping directly affects is the material's carrier concentration. In an intrinsic semiconductor under thermal equilibriu

51、m, the concentration of electrons and holes is equivalent. That is,</p><p>　　n = p = ni</p><p>　　If we have a non-intrinsic semiconductor in thermal equilibrium the relation becomes: </p>

52、<p>　　n0 * p0 = (ni)2</p><p>　　Where n is the concentration of conducting electrons, p is the electron hole concentration, and ni is the material's intrinsic carrier concentration. Intrinsic carrie

53、r concentration varies between materials and is dependent on temperature. Silicon's ni, for example, is roughly 1.6×1010 cm-3 at 300 kelvin (room temperature).</p><p>　　In general, an increase in do

54、ping concentration affords an increase in conductivity due to the higher concentration of carriers available for conduction. Degenerately (very highly) doped semiconductors have conductivity levels comparable to metals a

55、nd are often used in modern integrated circuits as a replacement for metal. Often superscript plus and minus symbols are used to denote relative doping concentration in semiconductors. For example, n + denotes an n-type

56、semiconductor with a high, ofte</p><p>　　Effect on band structure</p><p>　　Doping a semiconductor crystal introduces allowed energy states within the band gap but very close to the energy band t

57、hat corresponds with the dopant type. In other words, donor impurities create states near the conduction band while acceptors create states near the valence band. The gap between these energy states and the nearest energ

58、y band is usually referred to as dopant-site bonding energy or EB and is relatively small. For example, the EB for boron in silicon bulk is 0.045 eV, compared wi</p><p>　　Dopants also have the important effe

59、ct of shifting the material's Fermi level towards the energy band that corresponds with the dopant with the greatest concentration. Since the Fermi level must remain constant in a system in thermodynamic equilibrium,

60、 stacking layers of materials with different properties leads to many useful electrical properties. For example, the p-n junction's properties are due to the energy band bending that happens as a result of lining up

61、the Fermi levels in contacting r</p><p>　　This effect is shown in a band diagram. The band diagram typically indicates the variation in the valence band and conduction band edges versus some spatial dimensio

62、n, often denoted x. The Fermi energy is also usually indicated in the diagram. Sometimes the intrinsic Fermi energy, Ei, which is the Fermi level in the absence of doping, is shown. These diagrams are useful in explainin

63、g the operation of many kinds of semiconductor devices.</p><p>　　Preparation of semiconductor materials</p><p>　　Semiconductors with predictable, reliable electronic properties are necessary for

64、 mass production. The level of chemical purity needed is extremely high because the presence of impurities even in very small proportions can have large effects on the properties of the material. A high degree of crystal

65、line perfection is also required, since faults in crystal structure (such as dislocations, twins, and stacking faults) interfere with the semiconducting properties of the material. Crystalline faults</p><p>

66、　　Because of the required level of chemical purity and the perfection of the crystal structure which are needed to make semiconductor devices, special methods have been developed to produce the initial semiconductor mate

67、rial. A technique for achieving high purity includes growing the crystal using the Czochralski process. An additional step that can be used to further increase purity is known as zone refining. In zone refining, part of

68、a solid crystal is melted. The impurities tend to concentrate </p><p>　　In manufacturing semiconductor devices involving heterojunctions between different semiconductor materials, the lattice constant, which

69、 is the length of the repeating element of the crystal structure, is important for determining the compatibility of materials.</p><p>　　附錄B:外文資料翻譯—譯文部分</p><p><b>　　半導(dǎo)體</b></p>

70、<p>　　半導(dǎo)體是一種導(dǎo)電性能介于導(dǎo)體與絕緣體之間的固體材料。它能在此之間永久地或動(dòng)態(tài)地變化。</p><p>　　半導(dǎo)體在電子技術(shù)中有著非常重要的地位。半導(dǎo)體設(shè)備，由半導(dǎo)體材料制成的電子元件與現(xiàn)代消費(fèi)電子產(chǎn)品諸</p><p>　　如電腦，移動(dòng)電話和數(shù)位錄放音機(jī)等有著極為密切的關(guān)聯(lián)。硅是商業(yè)應(yīng)用上用做制造半導(dǎo)體的物質(zhì)，此外還有許多其他物質(zhì)也被用做制造半導(dǎo)體。</p&g

71、t;<p><b>　　晶格中的布拉格反射</b></p><p>　　第二種說法是自由電子流。當(dāng)由于核的作用而導(dǎo)致靜電勢(shì)下降，因?yàn)椴祭穹瓷湟恍┳杂呻娮恿鞅环瓷涠荒艽┩?，就形成了一個(gè)能帶隙。當(dāng)能量較低的價(jià)帶被電子完全填滿時(shí)，這種描述就不是那么清楚了。</p><p>　　由于自旋態(tài)包利不相容導(dǎo)致的能級(jí)分裂</p><p>　　

72、第三種說法是兩個(gè)原子。分離抬形成一個(gè)兩個(gè)電子在兩個(gè)原子間的自旋的共價(jià)鍵。新增的原子不應(yīng)導(dǎo)致分裂，而是增加了價(jià)帶。這就是硅通常被提取的方法。能隙是由一個(gè)電子獲得能量從低能態(tài)跳躍至高能態(tài)而形成的。這一能態(tài)被認(rèn)為是反鍵。但是大量的硅并沒有像電子流動(dòng)一樣失去原子那么簡單。同樣，這個(gè)模型也不適合去解釋在漸變抑制結(jié)中能隙是怎么樣順暢地變化。</p><p><b>　　能帶和導(dǎo)電</b></p&g

73、t;<p>　　就像其他固體一樣，在半導(dǎo)體中的電子所具有的能量被限制在基態(tài)與自由電子之間的幾個(gè)“能帶”里，也就是電子完全離開此材料所需要的能量。當(dāng)電子在基態(tài)時(shí)，相當(dāng)于此電子被束縛在原子核附近。每個(gè)能帶都有數(shù)個(gè)相對(duì)應(yīng)的量子態(tài)，而在這些量子態(tài)中，能量較低的都已經(jīng)被電子所填滿，能量最高的就被稱為價(jià)帶。半導(dǎo)體和絕緣體不同與金屬就是因?yàn)榘雽?dǎo)體材料中的價(jià)帶與導(dǎo)電帶之間的能隙很小，電子容易獲得能量而跳躍至導(dǎo)電帶。</p>

74、<p>　　半導(dǎo)體中的電子是否易于從價(jià)帶上跳躍至導(dǎo)電帶取決于能隙和充當(dāng)半導(dǎo)體和絕緣體導(dǎo)電能力分界線（一般是4eV）的能帶寬度。</p><p>　　圖中的共價(jià)鍵，一個(gè)電子跳躍到鄰近的價(jià)帶上。因?yàn)榘幌嗳菰?，電子被提升到一個(gè)那個(gè)價(jià)帶更高的反鍵態(tài)。在非域態(tài)圖中，諸如在一維空間中就像在一條電線上，由于每個(gè)能量都是由電子在某一個(gè)狀態(tài)下向某個(gè)方向定向移動(dòng)。對(duì)一個(gè)網(wǎng)狀電流來說，要使電子流向某一狀態(tài)下的一個(gè)方向是

75、需要一定能夠的能量的。對(duì)一個(gè)金屬來說，只需要一個(gè)非常小的能量，在半導(dǎo)體中需要一個(gè)比能隙更高的狀態(tài)。這種狀態(tài)經(jīng)常被描述為：最高的對(duì)電導(dǎo)率無影響的價(jià)帶。然而，當(dāng)溫度開始上升，高于絕對(duì)零度時(shí)，半導(dǎo)體中有許多能量被晶體震動(dòng)和對(duì)我們來說更為重要的使電子跳入價(jià)帶之上的傳導(dǎo)帶中所消耗，在傳導(dǎo)帶中的載流子被稱為自由電子，盡管在文章不引起歧義的情況下，他們經(jīng)常被簡稱為電子。</p><p>　　在價(jià)帶內(nèi)的電子獲得能量后躍升至傳導(dǎo)帶

76、時(shí)，便會(huì)在價(jià)帶內(nèi)留下一個(gè)空缺，也就是所謂的“電洞”。傳導(dǎo)帶中的電子和價(jià)帶中的電洞都對(duì)電流傳遞有貢獻(xiàn)。電洞本身不會(huì)移動(dòng)，但是其他電子可以移動(dòng)到這個(gè)電洞上面，并且同樣留下一個(gè)電洞在其本身位置上，這樣就等效于電洞本身往電子移動(dòng)的相反方向移動(dòng)，這樣的行為就使得電洞的電性呈正電。</p><p>　　固體原子間的共價(jià)鍵的強(qiáng)度是單個(gè)電子與原子間約束力的十倍，所以要想讓電子自由化并不是簡單的打破晶體結(jié)構(gòu)而已。</p>

77、;<p>　　電洞：電子缺失而形成的電荷載體</p><p>　　被引入半導(dǎo)體理論的電洞的概念，同樣也可以應(yīng)用于導(dǎo)體傳導(dǎo)帶內(nèi)的費(fèi)米能階。對(duì)大多數(shù)金屬來說，霍爾效應(yīng)顯示電子是電荷載體，但是有一些金屬具有幾乎完全被填充的傳導(dǎo)帶，霍爾效應(yīng)呈正電荷載體不是離子核心而是電洞。有這種特征的導(dǎo)體有鹽水溶液，等離子體。在一個(gè)金屬中，電子不需要很大的能量即可找到空缺的量子態(tài)供其跳躍、造成電流傳導(dǎo)。。有時(shí)甚至可以說成一

78、個(gè)電洞產(chǎn)生了，去解釋為什么電子為什么沒有落回低能狀態(tài)：因?yàn)樗也坏揭粋€(gè)電洞。最后電-光子散射和逃逸是阻抗的最主要原因。</p><p>　　費(fèi)米-狄拉克分布.當(dāng)能量態(tài)ε低于費(fèi)米能階μ，就有一個(gè)較高的幾率n被電子占據(jù)，而在這之上的，被電子占據(jù)的幾率就小的多了。能量分布函數(shù)受到溫度很大的影響。</p><p>　　電子的能態(tài)分布取決于其能級(jí)是否被占據(jù)。這種分布函數(shù)稱為費(fèi)米-狄拉克統(tǒng)計(jì)。這種分布

79、函數(shù)與電子的溫度有很大關(guān)系，費(fèi)米能階，在溫度低于絕對(duì)零度的條件下可以被認(rèn)為是能力上升之電子能態(tài)被占據(jù)。當(dāng)溫度高于絕對(duì)零度時(shí)，費(fèi)米能階為所有能階中，被電子占據(jù)幾率等于0.5的能階。</p><p>　　電子能量分布取決于溫度同樣解釋了為什么半導(dǎo)體的導(dǎo)電性非常依賴于溫度，如半導(dǎo)體在一個(gè)較低的溫度工作時(shí)只有少數(shù)的自由電子和電洞可以工作。</p><p><b>　　能量-動(dòng)量色散<

80、;/b></p><p>　　上述關(guān)于能帶結(jié)構(gòu)的內(nèi)容為了簡化，因此跳過了一個(gè)重要的現(xiàn)象：稱為“能量的色散”。同一個(gè)能帶內(nèi)之所以會(huì)有不同能量的量子態(tài)，原因是能帶的電子具有不同波向量，或是k-向量。在量子力學(xué)中，k-向量即為粒子的動(dòng)量</p><p>　　能量-動(dòng)量色散關(guān)系式能決定電子或電洞的“等效質(zhì)量”，以m*代表，公式如下：</p><p>　　等效質(zhì)量對(duì)于半

81、導(dǎo)體材料而言十分重要，例如它和電子或電洞的遷移率有高度的關(guān)聯(lián)，電子或電洞的遷移率影響著半導(dǎo)體的載子傳輸和電導(dǎo)率。</p><p>　　電子和電洞的等效質(zhì)量一般來說并不相同。這就影響了P-通道和N-通道MOSFET導(dǎo)電性不同。</p><p>　　半導(dǎo)體材料的傳導(dǎo)帶底部和價(jià)帶頂端在能量-動(dòng)量坐標(biāo)上可能會(huì)處在不同的k值，這種材料叫做“間接能隙材料”，例如硅或是鍺。相對(duì)地，如果某種材料的傳導(dǎo)帶底

82、部和價(jià)帶頂端有相同的k值，這種材料稱為“直接能隙材料”，最常見的例子是砷化鎵。直接能隙半導(dǎo)體在光電子學(xué)中是非常重要的，因?yàn)樗陌l(fā)光效率高過間接能隙材料很多。</p><p><b>　　載子的產(chǎn)生和復(fù)合</b></p><p>　　當(dāng)離子化的輻射能量落在半導(dǎo)體時(shí)，可能會(huì)讓價(jià)帶中的電子吸收到足夠能量而躍遷至傳導(dǎo)帶，并在價(jià)帶中產(chǎn)生一個(gè)電洞，這種過程叫做“電子-電洞對(duì)的產(chǎn)生

83、”。而其他夠大的能量，如熱能，也可以同樣產(chǎn)生出電子-電洞對(duì)。</p><p>　　電子-電洞對(duì)則會(huì)經(jīng)由復(fù)合的過程而被消滅。根據(jù)能量守恒的觀念，在傳導(dǎo)帶中的電子必須回到價(jià)帶，將所得到的能量釋放出來。能量釋放的形式包括熱能（以聲子的形式）或輻射能（以光子的形式）。</p><p>　　在某些狀態(tài)下，電子-電洞對(duì)的產(chǎn)生和復(fù)合速率是相等的。對(duì)于處于穩(wěn)態(tài)的電子-電洞對(duì)，在一個(gè)已給定的溫度下，其數(shù)量可

84、由量子統(tǒng)計(jì)求得。量子力學(xué)處理此類問題時(shí)必須同時(shí)遵守能量守恒和動(dòng)量守恒。</p><p>　　就像電子和電洞同時(shí)相遇的概率與他們產(chǎn)生的數(shù)量是成比例一樣，產(chǎn)物對(duì)在處于一個(gè)恒定溫度下的穩(wěn)態(tài)時(shí)，不會(huì)提供一個(gè)非常明顯的電場（可能激活載流子的兩種形態(tài)，促使它們向鄰近的區(qū)域移動(dòng)使他們相遇）或者外在的受迫對(duì)產(chǎn)生。產(chǎn)物是溫度的一個(gè)作用，就如同溫度可以提升得到足夠的熱能產(chǎn)生電子-電洞對(duì)的概率，近似的可用用公式1×exp(?

85、EG / kT)表示，k是麥克斯韋-玻爾茲曼常量，T是絕對(duì)溫度， EG是能隙。</p><p>　　載流子復(fù)合中心通過捕捉電子或電洞來完成配對(duì)來增加它們的相遇的幾率，復(fù)合中心可以是雜質(zhì)。像這樣的載流子復(fù)合中心有時(shí)被故意添加到半導(dǎo)體里，以降低到穩(wěn)態(tài)所需的時(shí)間。</p><p><b>　　半導(dǎo)體的摻雜</b></p><p>　　半導(dǎo)體之所以能廣

86、泛應(yīng)用在今日的數(shù)位世界中，憑借的就是其能借由在其晶格中植入雜質(zhì)改變其電性，這個(gè)過程稱之為摻雜。摻雜進(jìn)入本質(zhì)半導(dǎo)體的雜質(zhì)濃度與極性皆會(huì)對(duì)半導(dǎo)體的導(dǎo)電特性產(chǎn)生很大的影響。而摻雜過的半導(dǎo)體則稱為外質(zhì)半導(dǎo)體。</p><p><b>　　摻雜物</b></p><p>　　哪種材料適合作為某種半導(dǎo)體材料的摻雜物需視兩者的原子特性而定。一般而言，摻雜物依照其帶個(gè)被摻雜材料的電荷

87、正負(fù)被區(qū)分為受體與施體。施體原子帶來的價(jià)電子大多會(huì)與被摻雜的材料原子產(chǎn)生共價(jià)鍵，進(jìn)而被束縛。而沒有和被摻雜材料原子產(chǎn)生共價(jià)鍵的電子則會(huì)被施體原子微弱地束縛住，這個(gè)電子又稱為施體電子。和本質(zhì)半導(dǎo)體的價(jià)電子比起來，施體電子躍遷至傳導(dǎo)帶所需的能量較低，比較容易在半導(dǎo)體材料的晶格中移動(dòng)，產(chǎn)生電流。雖然施體電子獲得能量會(huì)躍遷至傳導(dǎo)帶，但并不會(huì)和本質(zhì)半導(dǎo)體一樣留下電洞，施體原子在失去了電子后會(huì)固定在半導(dǎo)體材料的晶格中。因此這種因?yàn)閾诫s而獲得多余電子

88、提供傳導(dǎo)的半導(dǎo)體稱為n型半導(dǎo)體，和施體相對(duì)的，受體摻雜后的半導(dǎo)體稱為p型半導(dǎo)體。n和p分別代表著材料中的多數(shù)載流子。相對(duì)的，另一種載流子就稱為少數(shù)載流子。少數(shù)載流子的存在取決于相對(duì)多數(shù)載流子而言較低濃度的熱激勵(lì)。</p><p>　　以一個(gè)硅的本質(zhì)半導(dǎo)體來說明雜質(zhì)的影響。硅有四個(gè)價(jià)電子，常用于硅的摻雜物有三價(jià)與五價(jià)的元素。當(dāng)只有三價(jià)元素?fù)诫s至硅半導(dǎo)體中時(shí)，三價(jià)元素扮演受體的角色。五價(jià)元素?fù)诫s至硅半導(dǎo)體中，則五價(jià)元

89、素扮演施體的角色。因此，一個(gè)硅半導(dǎo)體中摻雜了硼的就是p型半導(dǎo)體。若摻雜了磷的就成為n型半導(dǎo)體。</p><p><b>　　載子濃度</b></p><p>　　摻雜物濃度對(duì)于半導(dǎo)體最直接的影響在于其載子濃度。在熱平衡的狀態(tài)下，一個(gè)未經(jīng)摻雜的本質(zhì)半導(dǎo)體，電子與電洞的濃度相等，如下列公式所示： </p><p>　　n = p = ni</

90、p><p>　　如果我們有一個(gè)非本質(zhì)半導(dǎo)體，在熱平衡的狀態(tài)下，其關(guān)系就變?yōu)椋?</p><p>　　n0 * p0 = (ni)2</p><p>　　n是半導(dǎo)體內(nèi)的電子濃度，p則是半導(dǎo)體的電洞濃度，ni則是本質(zhì)半導(dǎo)體的載子數(shù)目。ni會(huì)隨著材料或溫度的不同而改變。對(duì)于室溫下（300K）的硅而言，ni大約是1.6×1010 cm-3。</p>&l

91、t;p>　　通常摻雜濃度越高，半導(dǎo)體的導(dǎo)電性就會(huì)變得越好，原因是能進(jìn)入傳導(dǎo)帶的電子數(shù)量會(huì)隨著摻雜濃度提高而增加。摻雜濃度非常高的半導(dǎo)體會(huì)因?yàn)閷?dǎo)電性接近金屬而被廣泛應(yīng)用在今日的集成電路制程來取代部分金屬。高摻雜濃度通常會(huì)在n或是p后面附加一上標(biāo)的“+”號(hào)，例如n +表示摻雜濃度非常高的n型半導(dǎo)體，反之例如p ?則代表輕摻雜的p型半導(dǎo)體。需要特別說明的是即使摻雜濃度已經(jīng)高到讓半導(dǎo)體“退化”為導(dǎo)體，摻雜物的濃度和原本的半導(dǎo)體原子濃度比起

92、來還是差距非常大。以一個(gè)有晶格結(jié)構(gòu)的硅本質(zhì)半導(dǎo)體而言，原子的濃度大約是5×1022 atoms/cm³，而一般集成電路制程里的摻雜濃度約在1013 cm-3至1018 cm-3之間。摻雜濃度在1018 cm-3以上的半導(dǎo)體在室溫下通常會(huì)被視為一個(gè)“簡并半導(dǎo)體”。重?fù)诫s的半導(dǎo)體中，摻雜物和半導(dǎo)體原子的濃度比約是千分之一，而輕摻雜則可能會(huì)到十億分之一的比例。在半導(dǎo)體制程，摻雜濃度都會(huì)依照所制造出元件的需求量身打造，以合于

93、使用者的需求。</p><p>　　摻雜對(duì)搬到能帶結(jié)構(gòu)的影響</p><p>　　摻雜之后的半導(dǎo)體的能帶會(huì)有所改變。依照摻雜物的不同，本質(zhì)半導(dǎo)體的能隙之間會(huì)出現(xiàn)不同的能階。施體原子會(huì)在靠近傳導(dǎo)帶的地方產(chǎn)生一個(gè)新的能階，而受體原子則是在靠近價(jià)帶的地方產(chǎn)生新的能階。假設(shè)摻雜硼原子進(jìn)入硅，則因?yàn)榕鸬哪茈A到硅的價(jià)帶之間僅有0.045電子伏特，遠(yuǎn)小于硅本身的能隙1.12電子伏特，所以在室溫下就可以使

94、摻雜到硅里的硼原子完全解離化。</p><p>　　摻雜物對(duì)于能帶結(jié)構(gòu)的另一個(gè)重大影響是改變了費(fèi)米能階的位置。在熱平衡的狀態(tài)下費(fèi)米能階依然會(huì)保持定值，這個(gè)特性會(huì)引出很多其他有用的電特性。舉例來說，一個(gè)p-n接面后其費(fèi)米能階必須保持在同樣的高度，造成無論是p型半導(dǎo)體或是n型半導(dǎo)體的傳導(dǎo)帶或價(jià)帶都會(huì)被彎曲以配合接面處的能帶差異。</p><p>　　上述的效應(yīng)可以用能帶圖來解釋，在能帶圖里橫軸

95、代表位置，縱軸則是能量。圖中也有費(fèi)米能階，半導(dǎo)體的本質(zhì)費(fèi)米能階通常以Ei來表示。在解釋半導(dǎo)體元件的行為時(shí)，能帶圖是非常有用的工具。</p><p><b>　　半導(dǎo)體材料的制造</b></p><p>　　為了滿足量產(chǎn)上的需求，半導(dǎo)體的電性必須是可預(yù)測(cè)并且穩(wěn)定的，因此包括摻雜物的純度以及半導(dǎo)體晶格結(jié)構(gòu)的品質(zhì)都必須嚴(yán)格要求。常見的品質(zhì)問題包括晶格的錯(cuò)位、雙晶面、或是堆棧

96、錯(cuò)誤都會(huì)影響半導(dǎo)體材料的特性。對(duì)于一個(gè)半導(dǎo)體元件而言，材料晶格的缺陷通常是影響元件性能的主因。晶格越大，就越難達(dá)到其結(jié)構(gòu)的要求。當(dāng)今的量產(chǎn)過程使用的晶錠直徑在四至十二英寸（300mm）之間</p><p>　　目前用來成長高純度單晶半導(dǎo)體材料最常見的方法稱為裘可拉斯基制程。這種制程將一個(gè)單晶的晶種放入溶解的同材質(zhì)液體中，再以旋轉(zhuǎn)的方式緩緩向上拉起。在晶種被拉起時(shí)，溶質(zhì)將會(huì)沿著固體和液體的接口固化，而旋轉(zhuǎn)則可讓溶質(zhì)