Silicon Wafer Ntau Lawm - Kev Paub

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Hluav Taws Xob Qib Polycrystalline Silicon (Polysilicon) Kev Ua Haujlwm

Schematic of a submerged electrode arc furnace used in the production of MG-Si

Daim duab 1Cov. Schematic ntawm submerged electrode arc qhov cub tawg siv nyob rau hauv kev tsim khoom ntawm MG-Si.

Siliconis yog lub caij thib ob tshaj plaws nyob hauv lub ntiaj teb ua kiav txhab (cov pa yog thawj). Nws tshwm sim ib txwm nyob hauv silicate (Si-O muaj) cov pob zeb thiab cov av xuab zeb. Lub tshuab hluav taws xob siv hluav taws xob siv hauv cov khoom lag luam semiconductor ntaus ntawv yog tsim los ntawm cov siab purity quartz thiab quartzite sands, uas muaj cov khoom tsis huv. Hluav taws xob qib silicon, lub npe siv rau qib ntawm silicon ua haujlwm hauv semiconductor ntaus khoom siv, yog cov khoom lag luam ntawm cov txheej txheem pib nrog kev hloov ntawm quartz lossis quartzite xuab zeb rau "metallurgical qib silicon" (MG-Si), hauv hluav taws xob arc rauv (Daim Duab 1) raws li cov tshuaj lom neeg:

SiO2+ C → Si + CO2

Silicon npaj qhov no yog hu ua "qib hlau" vim tias feem ntau ntawm cov khoom siv hauv ntiaj teb yeej nkag mus rau hauv cov hlau ua. Nws yog li 98% ntshiab.MG-Si tsis dawb huv txaus rau kev siv ncaj qha rau hauv kev tsim hluav taws xob. Ib feem me me (5% - 10%) ntawm kev lag luam thoob ntiaj teb ntawm MG-Si tau txais kev huv ntxiv rau kev siv hauv tshuab hluav taws xob. Kev ua kom huv huv ntawm MG-Si rau semiconductor (hluav taws xob) qib silicon yog cov txheej txheem ntau kauj ruam, qhia schematically hauv Daim duab 2. Hauv cov txheej txheem no, MG-Si yog thawj qhov av hauv pob-mill kom tsim tau zoo heev (75%< ; 40 µM) cov xaj uas tom qab ntawd pub rau Fluidized Bed Reactor (FBR). Muaj MG-Si reacts nrog anhydrous hydrochloric acid gas (HCl), ntawm 575 K (kwv yees li 300ºC) raws li cov tshuaj tiv thaiv:

Si + 3HCl → SiHCl3+ H2

Qhov tshuaj tiv thaiv hydrochlorination nyob hauv FBR ua rau cov khoom lag luam uas yog kwv yees li 90% trichlorosilane (SiHCl)3)). Qhov seem 10% ntawm cov roj uas tsim nyob rau hauv cov kauj ruam no feem ntau yog tetrachlorosilane, SiCl4, nrog qee qhov dichlorosilane, SiH2Cl2Cov. Cov pa roj sib xyaw no tau muab tso rau hauv cov txheej txheem sib cais uas lim cov trichlorosilane thiab sau thiab rov siv cov tetrachlorosilane thiab dichlorosilane by-products. Txoj kev ua kom huv no ua cov trichlorosilane tsis tshua muaj kev cuam tshuam nrog cov khoom tsis haum loj nyob rau qhov chaw qis rau ntau lab. Ua kom huv, cov tawv polycrystalline silicon yog tsim los ntawm cov siab huv trichlorosilane siv tus qauv hu ua "Cov Txheej Txheem Siemens." Hauv cov txheej txheem no, trichlorosilane yog diluted nrog hydrogen thiab pub rau ua kom muaj pa tshuaj vapor deposition reactor. Muaj, qhov kev tawm tsam cov teeb meem raug hloov kho kom polycrystalline silicon tau muab tso rau ntawm cov tshuab hluav taws xob uas muaj qhov sib txuas ntawm qhov sib xyaw ua ke raws li qhov thim rov qab ntawm trichlorosilane tsim cov tshuaj tiv thaiv:

SiHCl3+ H2→ Si + 3HC

Khoom siv los ntawm cov tshuaj tiv thaiv deposition (H2, HCl, SiHCl3, SiCl4thiab SiH2Cl2) tau yog qhov ua tiav thiab rov ua dua los ntawm trichlorosilane ntau lawm thiab kev ua kom huv huv raws li pom hauv daim duab 2. Kev qhia txog kev lag luam ntawm kev tsim khoom, kev ua kom huv thiab silicon cov txheej txheem uas cuam tshuam nrog semiconductor qib silicon yog qhov nyuaj dua cov lus piav qhia yooj yim no. Tseem muaj tus nab npawb ntawm cov kws kho khoom siv tshuaj tau tuaj yeem yog, thiab yog, siv rau polysilicon ntau lawm.

rocess flow diagram for the production of semiconductor grade (electronic grade) silicon

Daim duab 2Cov. Txheej txheem ntws daim duab rau kev tsim cov semiconductor qib (qib hluav taws xob) silicon.

Tib Crystal Silicon Wafer Fabrication

Lub tshuab silicon wafers zoo li yog li ntawm peb cov nyob hauv txoj kev lag luam semiconductor ua tau nyias nyias ntawm kev siv ib qho loj ntawm cov khoom siv silicon uas tau zus los ntawm melted hluav taws xob qib polycrystalline silicon. Cov txheej txheem tau siv rau hauv kev loj hlob ntawm cov khoom siv no ib tus neeg muaj npe hu ua Czochralski cov txheej txheem tom qab nws tsim, Jan Czochralski. Daim duab 3 qhia tau qhov pib ua ntu zus thiab cov cheebtsam koom nrog hauv Czochralski cov txheej txheem.

Schematic of Czochralski process (b) Process equipment (reproduced with permission, PVA TePla AG 2017)

Daim duab 3Cov. Schematic ntawm Czochralski cov txheej txheem (b) Cov cuab yeej siv cov txheej txheem (luam tawm nrog kev tso cai, PVA TePla AG 2017).

Cov txheej txheem Czochralski tau ua nyob rau hauv ib chav tsev uas tshem tau, feem ntau hu ua "cov rub tawm kom khov" uas tuav tau qhov cub loj, feem ntau quartz, thiab hluav taws xob cua sov siv (daim duab 3 (a)). Semiconductor qib polysilicon yog ntim (them) rau hauv qhov chaw crucible nrog rau tus nqi ntawm ib qho dopants xws li phosphorus lossis boron uas xav tau los muab cov khoom wafers teev P lossis N yam ntxwv. Kev tshem tawm yuav tshem tawm cov pa tawm ntawm cov kab tawm kom ua kom tsis txhob oxidation ntawm cov roj ua kua uas ntiab tawm thaum ua kev loj hlob. Lub txim crucible yog hluav taws xob ua kom kub mus rau qhov kub thiab txias kom txaus rau cov polysilicon (ntau dua 1421ºC). Thaum them cov tshuaj silicon tag nrho melted, lub noob me me siv lead ua, kev tsa ntawm ib tus pas nrig, tau qis qis rau hauv cov roj ntsha silicon. Cov noob siv lead ua feem ntau kwv yees li 5 hli diam thiab ntev li 300 hli. Nws ua raws li "pib" rau txoj kev loj hlob ntawm cov loj silicon siv lead ua los ntawm yaj. Cov noob siv lead ua tsa saum tus pas nrig nrog lub ntsej muag uas paub zoo tshaj plaws hauv cov yaj (siv lead ua sib cais tau txhais los ntawm "Miller Indices"). Xws li cov noob muaju, cov ntsej muag muaj Miller qhov taw qhia ntawm< 100>="">< 110=""> lossis< 111=""> feem ntau raug xaiv. Kev loj hlob uas siv lead ua los ntawm yaj yuav ua raws txoj kev pib no, muab qhov loj kawg nkaus rau ntawm ib qho khoom siv lead ua kom pom. Tom qab tso rau hauv yaj tag, cov noob siv lead ua maj mam qeeb (ob peb cm / teev) rub los ntawm yaj vim cov siv lead ua loj dua. Qhov rub ceev txiav txim siab qhov kawg ntawm txoj kab loj ntawm cov siv lead ua loj. Ob qho tib si siv lead ua thiab lub crucible yog tig thaum lub zog rub coj los txhim kho homogeneity ntawm cov siv lead ua thiab dopant faib. Qhov kawg loj siv lead ua yog cylindrical nyob rau hauv cov duab; Nws yog hu ua "boule." Czochralski kev loj hlob yog qhov kev lag luam tshaj plaws rau kev tsim cov khoom siv silicon siv lead ua pob zeb haum rau kev tsim cov khoom siv silicon rau cov khoom siv hluav taws xob ntau yam (cov khoom sib txawv) (paub tias CZ wafers). Cov qauv tuaj yeem ua cov nplais qhov loj txaus los tsim cov silicon wafers txog li 450 hli hauv txoj kab uas hla. Txawm li cas los xij, tus txheej txheem muaj qee qhov kev txwv. Txij li thaum lub pob paj loj hlob nyob rau hauv quartz (SiO2) crucible, qee qhov pa paug tuaj yeem ib txwm nyob hauv silicon (feem ntau 1018 atoms cm-3 lossis 20 ppm). Graphite crucibles tau siv kom tsis txhob muaj qhov paug ntawm no, txawm li cas los lawv ua cov pa roj carbon monoxide qhov cuam tshuam hauv silicon, txawm li ntawm ib qho kev txiav txim ntawm qhov ntau tsawg dua hauv kev ua kom zoo. Ob qho oxygen thiab carbon impurities qis dua qhov tsawg tshaj plaws cov neeg tsav tsheb diffusion ntev nyob rau hauv kawg silicon wafer. Dopant homogeneity hauv cov lus qhia axial thiab radial kuj tseem muaj kev txwv hauv Czochralski silicon, ua rau nws nyuaj rau tau txais wafers nrog resistivities ntau dua 100 ohm-cm.

Kev coj dawb huv silicon tuaj yeem tsim los ntawm ib txoj kev hu ua Float Zone (FZ) refining. Nyob rau hauv hom no, ib qho polycrystalline silicon ingot yog mounted hauv txoj kab kev loj hlob, nyob hauv qab nqus tsev lossis cua. Lub ingot tsis nyob rau hauv kev sib cuag nrog ib qho ntawm cov khoom sib xyaw hauv chav tshwj tsis yog rau cov pa hauv av thiab cov noob siv lead ua ntawm qhov paub txog ntawm nws qhov pib (Daim Duab 4). Lub ingot yog rhuab siv cov xov tooj cua tsis sib cuag-zaus (RF) coils uas tsim kom muaj thaj chaw ntawm cov khoom yaj nyob hauv cov nplaim taws, feem ntau ntev li 2 cm tuab. Hauv cov txheej txheem FZ, tus pas nrig txav mus lawm mus rau sab hauv qab, pub rau thaj chaw molten txav mus rau qhov ntev ntawm lub ingot, thawb impurities ua ntej ntawm cov yaj thiab tawm hauv qab kom huv siab ib leeg siv lead ua silicon. FZ silicon wafers muaj resistivities siab txog 10,000 ohm-cm.

Daim duab 4Cov. Ntab tsam siv lead ua kev loj hlob teeb.

Thaum tsim cov xim silicon, nws tau txiav rau hauv kev tswj kom ntev thiab txhua qhov ntev hauv av mus rau qhov xav tau txoj kab uas hla. Orientation flats uas qhia cov xaim hluav taws xob ntawm silicon doping thiab kev paub txog kev zam rau tsawg dua 200 hli txoj kab uas hla kuj yog hauv av rau lub pob hauv qhov theem no. Rau wafers nrog diameters tsawg dua 200 hli, thawj (loj tshaj plaws) tiaj tus yog taw qhia kom ncaj mus rau ib tug kev siv lead ua axis xws li< 111=""> lossis< 100=""> (saib Daim Duab 5). Cov xaim theem ob (me me) qhia tias tus wafer yog p-hom lossis n-hom. 200 hli (8-nti) thiab 300 hli (12-nti) wafers siv ib qho kev nqis siab ib txwm taw rau lub teeb tsa iav siv los qhia zam kev taw qhia tsis muaj qhov tsis muaj qhov taw qhia rau hom doping. Daim duab 3 pom qhov sib txawv ntawm hom wafer thiab kev tso nkag ntawm qhov tso rau ntawm wafer ntug.

Wafer flat designators for different wafer orientation and doping

Daim duab 5Cov. Wafer tiaj tus tsim qauv rau kev sib txawv ntawm wafer thiab doping.

Tom qab lub pob zeb tau ua tiav rau hauv txoj kab uas xav tau thiab cov flats tau tsim, nws tau txiav mus rau hauv cov hlais nyias siv uas siv lub pob zeb diamond encrusted hniav lossis hlau hlau. Cov npoo ntawm silicon slices feem ntau yog npawv ntawm cov qib no. Laser npav cim tsim hom silicon, kev tiv taus, chaw tsim khoom, thiab lwm yam kuj tau ntxiv ze rau ntawm cov thawj tiaj tiaj ntawm lub sijhawm no. Ob thaj chaw ntawm cov hlais tsis tiav yog av thiab lapped nqa tag nrho cov hlais rau hauv qab qhov tuab thiab qhov siab kam rau ua. Kev sib tsoo coj cov hlais mus rau hauv cov ntxhib tuab thiab ua siab tev kam rau tom qab uas cov txheej txheem lapping tshem cov khoom kawg ntawm cov tsis xav tau los ntawm cov nplais ntsej muag, tawm qhov chaw tiaj, tiaj thiab tsis tiav. Lapping feem ntau ua tiav kom haum rau ntawm tsawg dua 2.5 µm uniformity hauv wafer nto flatness.

Cov theem kawg hauv kev tsim cov tshuab silicon wafer koom nrog kev sib twetchingdeb ntawm cov khaubncaws sab nraud povtseg uas tej zaum tau ua rau cov khoom siv siv lead ua kev puas tsuaj thiab sib kis thaum pom, sib tsoo thiab sib tsoo; taug qab lostshuaj lom neeg kho tshuab polishing(CMP) los tsim cov xim zoo nkauj, khawb thiab puas dawb lub ntsej muag ntawm ib sab ntawm lub wafer. Cov tshuaj lom neeg etch yog ua tiav siv txoj kev daws teeb meem ntawm hydrofluoric acid (HF) tov nrog nitric thiab acetic acids uas tuaj yeem yaj silicon. Nyob rau hauv CMP, silicon slices yog mounted rau cov cab kuj thiab muab tso rau hauv lub tshuab CMP nyob txhua qhov chaw lawv yauv tshuaj lom neeg thiab tshuab polishing. Feem ntau, CMP ntiav cov khoom lag luam tawv polyurethane polishing zoo ua ke nrog kev nplua ntawm cov nplaim hluavtaws alumina lossis silica abrasive hais hauv cov kua roj. Cov khoom tiav ntawm CMP cov txheej txheem yog cov silicon wafer uas peb, raws li cov neeg siv, tau paub zoo. Nws muaj kev cuam tshuam zoo nkauj, cuam tshuam thiab kev puas tsuaj lub npoo dawb ntawm ib sab ntawm qhov uas cov khoom siv hluav taws xob muaj peev xwm muab tau kev qhia.

Caw Semiconductor Wafer Ntau Lawm

Cov tshuab hluav taws xob sib xyaw ua ke yog cov ntaub ntawv tseem ceeb hauv ntau cov tub rog thiab lwm yam khoom siv hluav taws xob tshwj xeeb xws li lasers, cov khoom siv hluav taws xob ntau, LEDs, cov khoom txais hluav taws xob, opto-electronic integrated circuits, thiab lwm yam. Cov.

Rooj 1 qhia cov npe ntawm cov elemental thiab binary (ob lub caij) compound semiconductors nrog rau cov xwm ntawm lawv cov kis sib txawv thiab nws lub zog loj. Ntxiv rau binary compound semiconductors, ternary (peb lub caij) compound semiconductors tseem paub thiab siv cov khoom siv los ua ke. Ternary compound semiconductors suav nrog cov khoom siv xws li aluminium gallium arsenide, AlGaAs, indium gallium arsenide, InGaAs thiab indium aluminium arsenide, InAlAs. Quarternary (plaub lub caij) compound semiconductors tseem paub thiab siv cov tshuab hluav taws xob niaj hnub no.

Qhov tshwj xeeb lub teeb ci muaj peev xwm ntawm cov khoom sib xyaw semiconductors vim yog qhov tseeb tias lawv ncaj qha cov kis sib txawv ntawm cov xov hluav taws xob. Kem 1 txhais tau hais tias cov neeg semiconductors muaj cov khoom no. Lub nthwv dej ntawm lub teeb tawm los ntawm cov khoom siv tsim los ntawm cov khoom siv ncaj qha sib cais semiconductors nyob ntawm cov kis ntawm lub zog. Los ntawm kev txawj ntse engineering cov qauv sib txawv ntawm cov khoom sib txuas ua los ntawm cov sib txawv ntawm cov tshuab hluav taws xob sib txuas nrog cov kab sib xyaw ncaj qha, cov kws ua haujlwm tau tsim cov khoom hluav taws xob lub xeev tau tsim tawm uas muaj los ntawm cov lasers siv rau hauv kev sib txuas lus fiber ntau kom muaj kev ua haujlwm zoo rau LED lub teeb. Cov lus sib tham ntxiv txog qhov cuam tshuam los ntawm kev ncaj qha piv rau qhov tsis ncaj ncaj ntawm cov kab sib txawv hauv cov khoom siv semiconductor yog dhau ntawm qhov ua tiav ntawm cov haujlwm no

Yooj yim, binary compound semiconductors tuaj yeem npaj hauv qhov loj, thiab ib leeg siv lead ua wafers yog tsim los ntawm cov txheej txheem zoo ib yam li cov siv hauv silicon wafer. GaAs, InP thiab lwm cov khoom sib xyaw ua ke (semiconductor ingots) tuaj yeem siv cov Czochralski lossis Bridgman-Stockbarger txoj kev nrog wafers npaj nyob rau hauv cov qauv zoo ib yam li silicon wafer ntau lawm. Cov txheej txheem ntawm thaj chaw ntawm cov khoom sib xyaw semiconductor wafers, (piv txwv li, ua rau lawv muaj kev cuam tshuam thiab tiaj tus) yog qhov nyuaj los ntawm qhov tseeb tias tsawg kawg yog ob lub ntsiab lus tam sim no thiab cov khoom no tuaj yeem hnov mob nrog etchants thiab abrasives hauv kev sib txawv.

Cov Khoom Siv Khoom	Npe	Cov mis	Zog Txi (eV)	Qhab Hom (I=ncaj qha; D=ncaj qha)
IV	Pob zeb diamond	C	5.47	I
	Txiag Silicon	Si	1.124	I
	Lub teb chaws Germanium	Ge	0.66	I
	Grey Tin	Qwj	0.08	D
IV-IV	Silicon Carbide	SiC	2.996	I
IV-IV	Silicon-Germanium	SixGe1-x	Lwm yam.	I
IIV-V	Txhuas Sulfide	PbS	0.41	D
	Txhuas Selenide	PbSe	0.27	D
	Lead Telluride	PbTe	0.31	D
III-V	Aluminium Nitride	AlN	6.2	I
	Txhuas Phosphide	AlP	2.43	I
	Txhuas Arsenide	AlAs	2.17	I
	Txhuas Antimonide	AlSb	1.58	I
	Gallium Nitride	GaN	3.36	D
	Gallium Phosphide	GaP	2.26	I
	Gallium Arsenide	GaAs	1.42	D
	Gallium Antimonide	GaSb	0.72	D
	Indium Nitride	Hauv	0.7	D
	Indium Phosphide	Hauv	1.35	D
	Indium Arsenide	Hauv	0.36	D
	Indium Antimonide	Hauv	0.17	D
II-VI	Zinc Sulfide	ZnS	3.68	D
	Zinc Selenide	ZnSe	2.71	D
	Zinc Telluride	ZnTe	2.26	D
	Cadmium Sulfide	CdS	2.42	D
	Cadmium Selenide	CdSe	1.70	D
	Cadmium Telluride	CdTe	1.56	D

Rooj 1Cov. Lub elementary semiconductors thiab binary compound semiconductors.