Cov ncauj lus kom ntxaws tsim cov txheej txheem ntawm chips!

█ Oxidation

Ua ntej, ib txheej oxide yog siv rau diced thiab polished wafer. Lub hom phiaj ntawm oxidation yog los tsim cov yeeb yaj kiab tiv thaiv (oxide txheej) ntawm qhov tsis yooj yim wafer nto. Cov oxide txheej no tiv thaiv cov wafer los ntawm kev cuam tshuam los ntawm cov tshuaj tsis huv, cov dej ntws tam sim no, thiab etching.

Qhuav oxidation suav nrog kev qhia cov pa ntshiab, uas ntws thoob plaws lub wafer nto thiab reacts nrog silicon los tsim ib txheej silicon dioxide. oxidation ntub dej siv ob qho tib si oxygen thiab soluble dej vapor heev.

█ Photolithography (txheej, ua ntej- ci, nthuav tawm, Tom qab- ci, Kev loj hlob)

Photolithography, yooj yim muab tso, yog zoo li lub tshuab luam ntawv "etching" cov qauv ntawm lub voj voog mus rau lub wafer.

Photolithography tuaj yeem muab faib ua peb kauj ruam tseem ceeb: txheej, raug, thiab kev loj hlob. Cia peb saib ntawm txhua tus tig.

Thawj yog txheej. Cov nplaum no hu ua photoresist, qee zaum kuj hu ua photoresist, thiab yog cov khoom siv photosensitive.

Muaj ob hom photoresist: zoo thiab tsis zoo.

Qhov zoo photoresist, thaum raug rau ib lub teeb ci tshwj xeeb (kev raug), ua rau muaj kev hloov pauv hauv nws cov qauv molecular, ua kom yaj yooj yim dua. Tsis zoo photoresist, ntawm qhov tod tes, ua nyuaj rau yaj tom qab raug. Qhov zoo photoresist yog siv nyob rau hauv feem ntau.

Txheej

Lub photomask yog iav los yog quartz phaj nrog ib txheej txheej ntawm cov khoom opaque (xws li chromium). Cov qauv no yog qhov tseem ceeb ntawm daim ntawv qhia rau lub nti, los yog kev sib xyaw ua ke ntawm lub voj voog.

Daim npog ntsej muag

Nyob rau hauv lub tshuab lithography, lub wafer thiab photomask yog precisely tsau. Tom qab ntawd, lub teeb tshwj xeeb (mercury vapor teeb lossis excimer laser) emits ib lub teeb ntawm lub teeb (ultraviolet light). Cov nqaj no dhau los ntawm kev txiav tawm hauv lub photomask thiab ntau lub lo ntsiab muag (kom pom lub teeb), thaum kawg projecting nws mus rau thaj tsam me me ntawm wafer.

Tus qauv intricate circuit yog li "projected" mus rau wafer.

Siv qhov zoo photoresist ua piv txwv, lub photoresist nyob rau hauv qhov chaw raug yuav yooj yim dua yaj. Lub unexposed photoresist tseem undamaged.

Cov khoom siv kho tshuab tuav lub wafer thiab photomask tas li txav mus los, thiab lub teeb beam txuas ntxiv illuminates lub wafer. Thaum kawg, circuitry rau ntau ntau mus rau pua pua ntawm chips yog "kos" ntawm tag nrho cov wafer.

Txoj Kev Lithography

Tom qab lub silicon wafer tawm ntawm lub tshuab lithography, nws dhau los ua cua sov thiab ci txheej txheem (ci rau 20 feeb ntawm 120{2}}180 degree), hu ua tom qab ci.

Lub hom phiaj ntawm kev tshaj tawm - ci yog kom ntseeg tau tias cov tshuaj tiv thaiv photochemical hauv photoresist tau ua tiav tag nrho, them nyiaj rau kev siv tsis txaus. Ncej- ci kuj txo lub nplhaib-zoo li cov qauv uas tshwm sim tom qab photoresist txoj kev loj hlob vim yog cov nyhuv yoj sawv.

Tom ntej no los txog kev loj hlob. Tom qab kis tau, lub wafer yog immersed nyob rau hauv ib tug txhim kho kev daws teeb meem. Cov tshuaj tsim tawm tshem tawm cov teeb pom kev zoo photoresist (zoo photoresist), nthuav tawm cov qauv.

█ Kev sib tw

Okay, cia peb tham ntxiv txog cov txheej txheem tsim chip. Tam sim no, txawm hais tias tus qauv pom, peb tsuas yog tshem tawm ib feem ntawm photoresist. Qhov peb xav tau tiag tiag tshem tawm yog cov txheej txheem oxide hauv qab (qhov tsis tiv thaiv los ntawm photoresist).

Hauv lwm lo lus, peb yuav tsum tau txuas ntxiv "kev khawb" tob. Cov txheej txheem siv nyob rau theem no yog etching. Etching txheej txheem muab faib ua ob hom: ntub etching thiab qhuav etching.

Kev ntub dej etching suav nrog immersing lub wafer hauv cov kua tshuaj uas muaj cov tshuaj tshwj xeeb, siv cov tshuaj tiv thaiv kom yaj cov qauv semiconductor (oxide zaj duab xis) tsis tiv thaiv los ntawm photoresist.

Qhuav etching siv plasma los yog ion beams los bombard lub wafer, tshem tawm cov unprotected semiconductor qauv.

Ob lub ntsiab lus tseem ceeb hauv cov txheej txheem etching: isotropy (los yog anisotropy) thiab kev xaiv.

ntub etching etches nyob rau hauv tag nrho cov lus qhia, li no lo lus "isotropy." Qhuav etching etches tsuas yog nyob rau hauv perpendicular kev taw qhia, li no lub sij hawm "anisotropy." Cov tom kawg yog kom meej meej zoo dua.

Thaum etching, ob txheej oxide thiab photoresist yog etched. Nyob rau hauv tib lub etching tej yam kev mob, qhov piv ntawm tus photoresist etching tus nqi rau etching tus nqi ntawm cov khoom raug etched (Oxide txheej) yog xaiv. Kom meej meej, peb yuav tsum tau etch me ntsis photoresist li sai tau thiab etch ntau oxide txheej li sai tau.

█ Doping (Ion Implantation)

Okay, qhov ntawd xaus qhov "qhov- ua" txheej txheem. Lub sijhawm no, wafer nto tau etched nrog ntau yam trench thiab qauv. Tom ntej no, cia peb saib cov txheej txheem doping.

Thaum qhia txog kev paub txog chips (Yuav ua li cas raws nraim li semiconductor chips ua haujlwm?), Kuv tau hais tias transistors yog lub tsev tsim cov chips. Txhua lub transistor yog raws li PN kev sib tshuam. Raws li tau pom hauv daim duab hauv qab no (MOSFET transistor, NPN), nws suav nrog P-qhov dej, N- qhov dej, channels, rooj vag, thiab lwm yam.

Yav dhau los photolithography thiab etching tsuas yog tsim lub qhov. Tom ntej no, peb yuav tsum tsim P- qhov dej thiab N- qhov dej raws li cov qhov no. Ntshiab silicon nws tus kheej tsis yog -conductive. Ua kom tsis yog -conductive ntshiab silicon ib semiconductor, peb yuav tsum qhia impurities (hu ua dopants) rau hauv silicon hloov nws cov khoom hluav taws xob.

Piv txwv li, doping silicon nrog phosphorus, antimony, thiab arsenic tuaj yeem tsim N- qhov dej. Doping nrog boron, txhuas, gallium, thiab indium tsim P-zoo.

N atoms muaj cov electrons dawb. P atoms muaj ntau lub qhov thiab me me ntawm cov electrons dawb. Los ntawm kev siv lub rooj vag thiab qhov hluav taws xob rau cov channel, cov khoom siv hluav taws xob hauv P atoms tau nyiam, tsim ib qho hluav taws xob channel (channel). Siv qhov hluav taws xob nruab nrab ntawm ob N atoms tsim ib qho tam sim no ntawm NPN junctions.

Raws li qhia hauv daim duab hauv qab no:

Hauv daim duab, hauv qab yog P-zoo substrate. Ob lub qhov yog N- qhov dej. Ntawd yog, thaum ua qhov no NPN transistor, ion implantation yog siv ua ntej pib oxidation txheej txheem. Lub substrate yog thawj zaug doped nrog boron (muaj ib qho me me ntawm phosphorus), dhau los ua P-zoo substrate. (Rau qhov yooj yim ntawm kev nyeem ntawv, kuv tsis tau piav qhia txog cov kauj ruam no ua ntej.) Tam sim no, lub qhov - ua ib feem tuaj yeem doped nrog phosphorus los ua N- zoo. Koj puas nkag siab? Lub hom phiaj ntawm doping yog los tsim ib qho kev sib tshuam PN, tsim cov transistor.

Doping suav nrog ob txheej txheem: thermal diffusion thiab ion implantation. Vim tias thermal diffusion yog qhov nyuaj rau kev ua tiav kev xaiv diffusion, ion implantation yog tam sim no siv rau feem ntau daim ntawv thov tshwj xeeb rau cov kev xav tau tshwj xeeb.

Ion implantation yog cov txheej txheem ntawm kev siv lub siab - lub zog particle beam kom ncaj qha mus rau cov impurities rau hauv silicon wafer.