功能材料4：半導(dǎo)體制造技術(shù)2013

1、Basic Properties of Crystal Materials晶體的宏觀通性晶體的宏觀通性 Gerneral Macro-properties l晶面角守恒性晶面角守恒性 Constancy of interfacial anglesl均勻性均勻性 homogeneityl各向異性各向異性 anisotropyl解理性解理性 cleavagel對(duì)稱性對(duì)稱性 symmetryRelationship between the physic properties and micro-symmetry of crystalsDefects of crystals3.2.1 微觀缺陷微觀缺陷

2、3.2.2 宏觀缺陷宏觀缺陷 【微觀缺陷【微觀缺陷】偏離偏離理想理想晶體晶體0 0維維: : 點(diǎn)缺陷點(diǎn)缺陷1 1維維: : 線缺陷線缺陷2 2維維: :面缺陷面缺陷3 3維缺陷維缺陷原子缺陷原子缺陷電子缺陷電子缺陷: 能級(jí)躍遷能級(jí)躍遷本征缺陷本征缺陷: : 熱缺陷熱缺陷非本征缺陷非本征缺陷: :雜質(zhì)缺陷雜質(zhì)缺陷( (固溶體固溶體) )非化學(xué)計(jì)量缺陷非化學(xué)計(jì)量缺陷韌形位錯(cuò)韌形位錯(cuò)固溶體固溶體多晶多晶(陶瓷陶瓷)非晶態(tài)非晶態(tài)表面界面表面界面晶界晶界表面表面納米粉體納米粉體納米結(jié)構(gòu)納米結(jié)構(gòu)螺旋位錯(cuò)螺旋位錯(cuò)晶粒晶粒 韌形位錯(cuò) edge dislocation 螺旋位錯(cuò) screw dislocatio

3、n特點(diǎn)： 1. 非平衡缺陷 2. 位錯(cuò)單位均為一個(gè)格矢，即b (Burgers Vector)3.2.2 宏觀缺陷宏觀缺陷 韌形位錯(cuò) edge dislocationEdge dislocation (line defect)位錯(cuò)的移動(dòng)：滑移螺旋位錯(cuò) screw dislocation單晶硅中觀察到的螺旋位錯(cuò)缺陷單晶硅中觀察到的螺旋位錯(cuò)缺陷孿晶界孿晶界小角度晶界小角度晶界高分辨率點(diǎn)電鏡：螺旋位錯(cuò)和小角度晶界高分辨率點(diǎn)電鏡：螺旋位錯(cuò)和小角度晶界1HRTEM of Screw Dislocations in a Small Angle Grain Boundary Dislocations for

4、m at the interface between the first layer of gallium nitride to be deposited and the sapphire substrate. The dislocations can thread their way into the active layer of the device, but do not seem to degrade the device properties.【觀缺陷觀缺陷】Macrocopic defects:l開裂開裂 splitting, l包裹體包裹體 inclusionl生長層生長層 g

5、rowth layer l生長條紋生長條紋 growth striationl胞狀組織胞狀組織 cellular structrue l楔化楔化 wedging包裹體包裹體開裂開裂生長條紋生長條紋 生長層生長層生長層生長層生長條紋生長條紋 Silicon single crystals were grown by the floating-zone method using an infrared image furnace in the wide range of oxygen partial pressure defined at the inlet of the furnace 3.3

6、半導(dǎo)體晶體及晶片制備技術(shù)半導(dǎo)體晶體及晶片制備技術(shù)Processing Technology of SemiconductorCrystal & its Wafer From sand to wafer3.3.1 概述概述 Introduction lThe outer crust of this planet consists of all kinds of silicates (Si + O + something else). Si, in fact, accounts for about 26 % of the crust, while O about 49 %.lLiquid

7、Si indeed does react with all substances known to man - it is an universal solvent. This makes crystal growth from liquid Si somewhat tricky, because how do you contain your liquid Si? Fortunately, some materials - especially SiO2 - dissolve only very slowly.lBut(!) there will always be some dissolv

8、ed SiO2 and therefore oxygen in your liquid Si, and that makes it hard to produce Si crystals with very low oxygen concentrations. 3.3.2 硅原料處理和提純硅原料處理和提純 Producing Raw Silicon and its purifyingSiO2 + 2C = Si + 2CO2000oC Purifying of siWhat we do have to do is to purify the MG-Si - about 109 fold!（a）

9、First, Si is converted to SiHCl3 in a fluid bed Si + 3HCl = SiHCl3 + H2（b）Second, the SiHCl3 is distilled (like wodka), resulting in extremely pure Trichlorosilane（三氯硅烷）（c） Third, high-purity Si is produced by a Chemical Vapor Deposition (CVD) processCVD Schematic diagram 以SiHC3 (8N) 為原料，通過CVD，得到超純的

10、多晶硅。（hyperpure poly-Si） 1000oC SiHCl3 + H2 Si + 3 HClMore information3.3.3 單晶制備單晶制備 Single Crystal GrowthCzochrolski process 又稱：直拉法又稱：直拉法 或或 喬赫拉斯法喬赫拉斯法 Essentially, a crystal is pulled out of a vessel containing liquid Si by dipping a seed crystal into the liquid at a surface temperature of the melt

11、 just above the melting point.Everything else determines the quality and homogeneity - crystal growing is still as much an art as a science! Here we only look at one major point, the segregation coefficient kseg of impurity atomsEquilibrium refers to a growth speed of 0 mm/min or, more practically,

12、very low growth rates. On the positive side, the crystal will be cleaner than the liquid, crystal growing is simultaneously a purification method. The negative side: The distribution of impurities - and that includes the doping elements and oxygen - will change along the length of a crystal - a homo

13、geneous doping etc. is difficult to achieve.This is Why practically only As, P, and B are used for doping? Their segregation coefficient is close to 1. (But Bi difficult or impossible).More information【 區(qū)熔法區(qū)熔法 】Float Zone Crystal Growth 原理：原理：The method was first used for purification taking advanta

14、ge of the small segregation coefficients of many impurities. The impurities contained in the feed material would then prefer to remain in the melt and thus could be swept to the end of the feed stock. 特點(diǎn)特點(diǎn)：Since the melt never comes into contact with anything but vacuum (or inert gases), there is no

15、 incorporation of impurities that the melt picks up by dissolving the crucible material as in the CZ crystal growth method. This is especially true for oxygen, which can not be avoided in CZ crystal growth. FZ crystals therefore are always used when very low oxygen concentrations are important.區(qū)熔法原理

16、圖區(qū)熔法原理圖區(qū)熔法提純原理圖區(qū)熔法提純原理圖3.3.4 晶片技術(shù)晶片技術(shù) Wafer Technology晶片拋光晶片拋光 (lapping)3. 4 半導(dǎo)體芯片加工技術(shù)Technologies for Processing Semiconductor(From Wafer to Chip)平板印刷技術(shù)平板印刷技術(shù) Si氧化技術(shù)氧化技術(shù)濺射技術(shù)濺射技術(shù)CVD技術(shù)技術(shù)外延技術(shù)外延技術(shù) 分子束外延技術(shù)分子束外延技術(shù)離子注入技術(shù)離子注入技術(shù)等離子腐蝕技術(shù)等離子腐蝕技術(shù)化學(xué)腐蝕技術(shù)化學(xué)腐蝕技術(shù)蒸發(fā)技術(shù)蒸發(fā)技術(shù)旋式涂布技術(shù)旋式涂布技術(shù)半導(dǎo)體芯片相關(guān)制造技術(shù)半導(dǎo)體芯片相關(guān)制造技術(shù)Si(P)N-WellS

17、iO2N+P+D1A1D2CAPSA2Si(P)SiO2Si(P)SiO2Surface pictureSi(P)SiO2Surface pictureN-WellN-WellSi(P)SiO2Si3N4Surface pictureSi(P)N-WellSiO2Si3N4Surface pictureN-WellSiO2Si(P)Si3N4Surface pictureN-WellSiO2Si(P)Surface pictureN-WellSiO2Si(P)Surface picturePolyN-WellSi(P)Surface pictureSiO2PolyN-WellSi(P)SiO2

18、Surface pictureLPTEOSN-WellSi(P)SiO2PolySpacerSurface pictureN-WellSi(P)SiO2PolySurface pictureSi(P)N-WellSiO2PolySurface pictureN-WellSi(P)SiO2Surface pictureN+P+D1N-WellSi(P)SiO2Surface pictureN+P+D1W1N-WellSi(P)SiO2Surface pictureN+P+D1N-WellSi(P)SiO2Surface pictureN+P+D1ALN-WellSi(P)SiO2Surface

19、pictureN+P+D1ALN-WellSi(P)SiO2Surface pictureN+P+D1ALD2Si(P)Surface pictureN-WellSiO2N+P+D1ALVIAD2Si(P)Surface pictureN-WellSiO2N+P+D1ALA2D2Si(P)N-WellSiO2N+P+D1A1D2CAPSA2CAPSPETEOSTEOSSurface pictureA2A1SiO2-VIA平板印刷技術(shù)平板印刷技術(shù) Si氧化技術(shù)氧化技術(shù)濺射技術(shù)濺射技術(shù)CVD技術(shù)技術(shù)外延技術(shù)外延技術(shù) 分子束外延技術(shù)分子束外延技術(shù)離子注入技術(shù)離子注入技術(shù)等離子腐蝕技術(shù)等離子腐蝕技術(shù)化

20、學(xué)腐蝕技術(shù)化學(xué)腐蝕技術(shù)蒸發(fā)技術(shù)蒸發(fā)技術(shù)旋式涂布技術(shù)旋式涂布技術(shù)半導(dǎo)體芯片相關(guān)制造技術(shù)半導(dǎo)體芯片相關(guān)制造技術(shù)Lithography Techniques掩模層掩模層光阻層光阻層曝光曝光抗蝕膜顯影抗蝕膜顯影圖案轉(zhuǎn)移圖案轉(zhuǎn)移去除光阻層去除光阻層去除掩模層去除掩模層圖案層圖案層完成圖案完成圖案電磁波光頻部分：紫外、可見、紅外電磁波光頻部分：紫外、可見、紅外50.2 eV能量能量eV極遠(yuǎn)紫外光刻技術(shù)極遠(yuǎn)紫外光刻技術(shù)EUV lithography TechniquesThermal oxidation. This means that a solid state reaction (Si + O2 = S

21、iO2) is used: Just expose Si to O2 at sufficiently high temperatures and an oxide will grow to a thickness determined by the temperature and the oxidation time.【 】【外延技術(shù)外延技術(shù)】Epitaxy單晶襯底單晶襯底 + 單晶膜單晶膜 外延生長外延生長 Points:lDoping of the epitaxial layer with high precision (e.g. 5 Wcm 5%), and the doping is

22、usually very different from that of the substrate. The picture on the right symbolizes that by the two differently colored doping atoms.lPrecise thickness control, e.g. d = 1,2 m 10% over the entire wafer, from wafer to wafer and from day to day. Now there is a challenge: If you met the first point

23、and thus cant tell where the interface is - how do you measure the thickness? (The answer: Only electronically, e.g. by finding the position of the pn-junction produced).lCleanliness: No contaminants diffusing into the substrate and the epitaxial layer are allowed.Many materials that we wish to depo

24、sit have very low vaporpressures and thus are difficult to transport via gases.One solution is to chemically attach the metal (Ga, Al, Cu,etc) to an organic compound that has a very high vaporpressure. The organic-metal bond is very weak and can be broken viathermal means on wafer, depositing the me

25、tal with the highvapor pressure organic being pumped away.Metal Organic Chemical Vapor DepositionMBE (Molecular Beam Epitaxy). 背景：超晶格材料要求，是CVD外延技術(shù)的延伸。特點(diǎn)：每層10nm 精度1個(gè)原子層MBE: 1 m/h (CVD 1-10 m/min). Every atom reaching the surface of the heated substrate has enough time to migrate around and find his p

26、lace to build up a new crystal lattice. 超晶格超晶格superlattice超晶格超晶格 superlattice 【濺射技術(shù)濺射技術(shù)】Sputtering or Sputter Deposition(物理氣相沉積-1)lThe target atoms hit the substrate with an energy large enough so they get stuck, but not so large as to liberate substrate atoms. Sputtered layers therefore usually sti

27、ck well to the substrate (in contrast to other techniques, most notably evaporation).lAll atoms of the target will become deposited, in pretty much the same composition as in the target. It is thus possible, e.g., to deposit a silicide slightly off the stoichiometric composition (advantageous for al

28、l kinds of reason). In other words, if you need to deposit e.g. TaSi2 - x with x 0,01 - 0,1, sputtering is the way to do it because it is comparatively easy to change the target composition.lThe target atoms hit the substrate coming from all directions. In a good approximation, the flux of atoms lea

29、ving the target at an angle F relative to the normal on the target is proportional to cos F. This has profound implications for the coverage of topographic structures.lHomogeneous coverage of the substrate is relatively easy to achieve- just make the substrate holder and the target big enough. The p

30、rocess is also relatively easily scaled to larger size substrates - simply make everything bigger.More information【離子注入技術(shù)離子注入技術(shù)】Ion Implantation(物理氣相沉積-2)What is ion implantation? Ions of some material - almost always the dopants As, B, P - are implanted, i.e. shot into the substrate原原理理圖圖離子注入技術(shù)在高技術(shù)陶瓷用于表面改性離子注入技術(shù)在高技術(shù)陶瓷用于表面改性only Sb (as dopant) and occasional