Kev Siv Cov Hlau Hauv Kev Tsim Khoom Siv Semiconductor
Cov khoom siv semiconductor—xws li transistors, diodes, sensors, integrated circuits (ICs), thiab processors—yog lub hauv paus ntawm thev naus laus zis niaj hnub no. Tom qab lawv qhov kev ua tau zoo thiab qhov me me tas li yog ib qho txheej txheem tsim khoom nyuaj, meej, thiab nyob ntawm cov khoom siv heev. Ib pawg ntawm cov khoom siv uas lub luag haujlwm tsis tuaj yeem hloov pauv yog hlau. Cov hlau tsis yog siv ua "xov hlau" uas ua hluav taws xob xwb tab sis kuj yog cov khoom sib txuas hluav taws xob, cov teeb meem sib kis, kev sib txuas ntawm cov khoom sib xyaw, thiab cov khoom siv ua haujlwm hauv lithography thiab cov txheej txheem ntim khoom. Tsab xov xwm no tham txog yuav ua li cas siv cov hlau hauv kev tsim khoom siv semiconductor, cov hom hlau uas feem ntau siv, thiab cov teeb meem thiab cov lus qhia ntawm lawv txoj kev loj hlob.
1. Lub luag haujlwm ntawm cov hlau hauv cov khoom siv semiconductor
Feem ntau, cov hlau hauv cov khoom siv semiconductor muaj ntau lub luag haujlwm tseem ceeb:
1. Kev sib txuas (xaim hluav taws xob): Txuas cov transistors thiab lwm yam khoom hauv lub nti los ntawm txoj kev hlau uas tuab heev thiab ntau txheej (kev sib txuas ntau txheej).
2. Cov kev sib cuag Ohmic thiab cov kev sib cuag Schottky: Tsim ib qho kev sib txuas hluav taws xob ntawm cov hlau thiab ib lub semiconductor. Cov kev sib cuag Ohmic tso cai rau cov hluav taws xob ntws mus rau ob qho kev taw qhia nrog kev tiv thaiv qis, thaum cov kev sib cuag Schottky tsim ib lub diode nrog cov yam ntxwv rectifying.
3. Txheej thaiv thiab txheej nplaum: Tiv thaiv kev sib kis ntawm cov hlau atoms mus rau hauv cov khoom siv semiconductor lossis dielectric, thiab pab cov hlau lo rau txheej hauv qab no.
4. Lub qhov rooj hluav taws xob ntawm lub transistor: Hauv qee cov thev naus laus zis, hlau yog siv los tsim lub qhov rooj hluav taws xob ntawm MOSFET rau kev tswj hwm channel zoo dua thiab qis dua qhov tsis kam.
5. Cov ntaub ntawv hauv cov txheej txheem tsim khoom: Cov hlau thiab cov hlau sib xyaw yog siv ua cov ntaub thaiv tawv, cov txheej tiv thaiv, lossis cov khoom siv tshuaj rau kev tso thiab etching.
6. Kev ntim khoom thiab kev sib txuas ntawm cov chip: Kev siv cov hlau nplaum, kev sib txuas ntawm cov hlau, kev sib tsoo, thiab ntau yam hlau sib xyaw ua ke yog siv los txuas cov chip rau lub rooj tsavxwm thiab tiv thaiv lub cuab yeej los ntawm ib puag ncig.
Hauv lwm lo lus, qhov kev ua tau zoo ntawm cov chips niaj hnub no tsis yog txiav txim siab los ntawm silicon lossis lwm yam khoom siv semiconductor xwb, tab sis kuj los ntawm seb cov hlau raug xaiv thiab koom ua ke li cas.
2. Cov hlau rau kev sib txuas: los ntawm txhuas mus rau tooj liab thiab cobalt
Hauv cov tiam neeg thaum ntxov ntawm ICs, txhuas (Al) yog qhov kev xaiv tseem ceeb rau kev sib txuas vim nws yooj yim rau kev tso nyiaj, pheej yig, thiab sib xws nrog cov txheej txheem tsim khoom ntawm lub sijhawm. Txawm li cas los xij, raws li qhov ceev ntawm transistor nce thiab qhov xav tau tam sim no nce ntxiv, cov teeb meem xws li electromigration - kev txav mus los ntawm cov hlau atoms vim muaj cov electron ntws siab - ua rau txoj kev tawg thiab txo qis kev ntseeg siab.
Tom qab ntawd, kev lag luam tig mus rau tooj liab (Cu) vim nws muaj qhov tsis kam tiv taus qis dua li txhuas, txo qhov poob hluav taws xob thiab ua kom lub teeb liab ceev dua. Txawm li cas los xij, tooj liab nthuav tawm qhov kev cov nyom: Cu yooj yim diffuses rau hauv dielectrics (piv txwv li, SiO₂ lossis low-k dielectrics) thiab tuaj yeem ua rau cov khoom hluav taws xob puas tsuaj. Yog li ntawd, Cu feem ntau siv nrog txheej thaiv xws li tantalum (Ta) lossis tantalum nitride (TaN).
Hauv cov thev naus laus zis me dua (cov nodes siab heev), qhov kev sib txuas ntawm qhov sib txuas ua rau me dua, ua rau muaj kev tiv thaiv ntxiv, thiab cov teebmeem ciam teb (kev tawg ntawm qhov chaw) ua rau muaj kev cuam tshuam ntau dua. Rau qee cov txheej, kev siv cobalt (Co) lossis ruthenium (Ru) ua lwm txoj hauv kev / ua tiav rau Cu tau pib tshwm sim vim tias nws tuaj yeem muab kev ua tau zoo dua ntawm qhov me me thiab txo qhov xav tau rau cov teeb meem tuab.
3. Kev sib cuag ntawm cov hlau thiab semiconductor: ohmic thiab Schottky
Qhov kev sib cuag ntawm cov hlau thiab semiconductor yog ib qho tseem ceeb tshaj plaws. Yog tias qhov kev sib cuag tsis kam dhau, lub transistor yuav kub dhau sai thiab poob kev ua haujlwm. Hauv cov khoom siv CMOS niaj hnub no, cov chaw sib cuag / ntws dej thiab cov ntsaws sib cuag tau tsim los kom muaj qhov tsis kam qis tshaj plaws.
Qee cov hlau thiab cov tshuaj sib xyaw uas feem ntau siv rau kev sib cuag suav nrog:
– Titanium (Ti): feem ntau siv ua cov nplaum thiab cov txheej txheem tiv thaiv los tsim cov silicides.
- Nickel (Ni) thiab cobalt (Co): feem ntau nyob rau hauv cov txheej txheem silicidation (piv txwv li NiSi, CoSi₂) los txo qhov kev tiv tauj hauv silicon.
– Tungsten (W): siv dav ua "plug" los sau cov qhov sib cuag (contact/via fill) vim nws ruaj khov thiab haum rau CVD (chemical vapor deposition) deposition.
– Platinum (Pt) los yog palladium (Pd): siv tau los tsim cov Schottky sib cuag los yog rau qee yam kev siv uas xav tau kev ruaj khov tshuaj lom neeg siab.
Hauv cov khoom siv ua los ntawm cov semiconductors uas tsis yog silicon—xws li GaN (gallium nitride) lossis SiC (silicon carbide)—kev xaiv cov hlau sib cuag ua qhov tseem ceeb dua vim muaj qhov sib txawv ntawm cov qauv zog, qhov kub siab, thiab qhov chaw ua haujlwm hnyav dua (piv txwv li, cov khoom siv hluav taws xob).
4. Txheej thaiv, txheej liner, thiab txheej nplaum
Vim tias cov chips niaj hnub no me me heev, cov hlau atoms tuaj yeem tawg thiab ua rau muaj kev xau, luv luv, lossis hloov pauv hauv cov transistor parameters. Yog li ntawd, cov txheej nyias nyias raug siv, uas ua haujlwm hauv qab no:
- Kev thaiv kev sib kis: tiv thaiv kev sib kis ntawm Cu lossis lwm yam hlau.
- Liner: pab sau cov yam ntxwv nqaim (trench / via) kom sib npaug.
- Txheej nplaum: ua kom lo rau zoo dua.
Cov ntaub ntawv siv ntau suav nrog Ta/TaN, Ti/TiN, W, thiab hauv kev tshawb fawb tsis ntev los no, Ru, Mn-based barriers, lossis ultra-thin layers raws li 2D cov ntaub ntawv ua diffusion barriers. Thaum cov nodes mus txog, qhov kev sib tw yog ua kom qhov barrier nyias li sai tau thaum tseem ua haujlwm tau zoo, vim tias qhov barrier uas tuab dhau "notes" qhov chaw ntawm txoj kev thiab ua rau muaj kev tiv thaiv ntau ntxiv.
5. Hlau hauv cov qauv transistor: lub rooj vag hlau thiab high-k
Hauv cov transistors MOSFET niaj hnub no, tshwj xeeb tshaj yog txij li thaum qhia txog cov rooj vag siab-k/hlau, hlau tau ua lub luag haujlwm tseem ceeb hauv cov qauv rooj vag. Yav dhau los, cov rooj vag polysilicon feem ntau siv, tab sis lawv ntsib teeb meem xws li qhov cuam tshuam ntawm kev puas tsuaj thiab kev sib raug zoo nrog cov dielectrics siab-k. Nrog cov rooj vag hlau, kev tswj hwm electrostatic tau zoo dua thiab kev xau tuaj yeem raug tswj hwm.
Cov ntaub ntawv siv sib txawv, xws li titanium nitride (TiN), tantalum nitride, lossis kev sib xyaw ua ke ntawm cov hlau uas tsim los ua kom tiav qhov kev ua haujlwm kom raug (yog li ntawd qhov hluav taws xob qhov txwv ua tau raws li tus qauv tsim). Ntawm no, cov hlau tsis yog tsuas yog tus neeg coj hluav taws xob xwb; nws cov khoom siv hluav taws xob ntawm qhov chaw txiav txim siab tus cwj pwm ntawm transistor.
6. Siv cov hlau rau hauv cov txheej txheem tso thiab cov qauv
Kev tsim cov khoom siv chip suav nrog kev tso cov txheej hlau nyias nyias los ntawm ntau txoj kev, suav nrog:
- PVD (Lub Cev Vapor Deposition): zoo li sputtering, feem ntau rau Al, Ti, Ta, thiab lwm yam.
- CVD (Tshuaj lom neeg Vapor Deposition): feem ntau siv rau W (tungsten) plugs thiab qee cov txheej hlau.
– ALD (Atomic Layer Deposition): tseem ceeb heev rau cov txheej nyias nyias thiab cov txheej conformal ntawm cov qauv 3D, piv txwv li cov teeb meem / cov ntaub thaiv, cov rooj vag hlau, thiab qee cov ntaub ntawv sib cuag.
Tom qab tso cov hlau, yuav tsum tau ua qauv siv lithography thiab etching lossis cov txheej txheem damascene (tshwj xeeb tshaj yog rau Cu), uas cuam tshuam nrog kev tsim cov trenches hauv dielectric, sau lawv nrog hlau, thiab tom qab ntawd polishing lawv siv Chemical Mechanical Planarization (CMP). Cov txheej txheem no xav tau cov slurry thiab chemistry kom raug los tsim ib qho chaw tiaj tus yam tsis ua rau cov txheej hauv qab puas tsuaj.
7. Hlau ntawm lub ntim khoom: solder, bump, thiab wire bonding
Thaum lub wafer ua tiav lawm, lub chip raug txiav (diced) thiab ntim. Nyob rau theem no, hlau kuj tseem ceeb:
- Kev sib txuas ntawm cov hlau siv kub (Au), txhuas (Al), lossis tooj liab (Cu) hlau.
- Kev sib tsoo thiab flip-chip siv cov ncej hlau / bumps thiab solder rau kev sib txuas ceev ceev thiab suav cov pins loj.
- Cov khoom siv niaj hnub no feem ntau yog tin (Sn) raws li cov hlau sib xyaw (piv txwv li Sn-Ag-Cu) los hloov cov hlau txhuas (Pb) rau cov laj thawj ib puag ncig.
Cov khoom ntim khoom siab heev xws li chiplets, 2.5D/3D kev sib koom ua ke, thiab TSV (through-silicon via) ua rau muaj qhov xav tau cov khoom siv hlau uas muaj kev ntseeg siab ntau ntxiv, vim tias qhov ceev ntawm kev sib txuas thiab kev tso cua sov tawm ntau dua.
8. Cov teeb meem tseem ceeb: kev hloov pauv hluav taws xob, kev xeb, thiab kev tiv taus ntawm qhov nanoscale
Thaum qhov loj me dua, kev siv hlau ntsib teeb meem loj heev, suav nrog:
– Electromigration: txoj kev hlau tuaj yeem raug puas tsuaj los ntawm cov hluav taws xob siab hauv cov ntu me me.
- Ua kom muaj kev tiv taus zoo dua: ntawm qhov nanoscale, cov electrons sib tsoo ntau dua nrog cov ciam teb ntawm cov noob thiab cov nto, ua rau muaj kev tiv thaiv ntau dua.
- Kev xeb thiab kev sib raug zoo ntawm cov tshuaj lom neeg: tshwj xeeb tshaj yog nyob rau hauv cov theem tsim khoom uas muaj ntau yam tshuaj lom neeg thiab qhov kub siab.
- Cov kev txwv ntawm cov teeb meem: cov teeb meem yuav tsum nyias dua thiab tseem tiv taus kev sib kis, uas yog qhov nyuaj rau kev siv tshuab.
Yog li ntawd, kev tshawb fawb txog cov khoom siv hlau rau semiconductors txuas ntxiv mus, suav nrog kev tshawb nrhiav Co, Ru, Mo, nrog rau cov txheej txheem tshiab xws li lwm cov khoom siv sib txuas thiab cov txheej txheem tso tawm atomic.
9. Cov kev taw qhia yav tom ntej ntawm kev siv hlau
Cov qauv yav tom ntej hauv kev lag luam semiconductor tab tom tsav tsheb siv cov hlau "engineered" ntau dua ntawm qib atomic. Cov nodes siab heev thiab 3D architectures (FinFET, GAA nanosheet, thiab lwm yam) xav tau cov txheej hlau sib xws, ultra-thin nrog cov interfaces huv si. Ntxiv mus, qhov xav tau kev siv hluav taws xob zoo thiab ceev kuj ua rau kev xaiv cov hlau rau kev sib txuas thiab kev sib cuag yog qhov tseem ceeb.
Nyob rau sab ntim khoom, qhov yuav tsum tau muaj bandwidth siab thiab kev sib koom ua ke sib txawv yog tsav tsheb kev tsim kho tshiab hauv kev sib txuas, kev sib tsoo, thiab cov hlau sib txuas. Hlau tsis yog tsuas yog ib qho khoom txhawb nqa xwb, tab sis yog ib feem tseem ceeb ntawm kev tsim qauv, kev ua tau zoo, thiab kev ntseeg tau.
Xaus
Cov hlau ua lub luag haujlwm tseem ceeb hauv kev tsim cov khoom siv semiconductor: ua cov kev sib txuas, kev sib cuag, cov teeb meem, cov rooj vag hlau, thiab lub hauv paus ntawm kev ntim khoom. Kev xaiv hlau tsis yog txiav txim siab los ntawm kev coj hluav taws xob xwb, tab sis kuj los ntawm kev sib kis, kev nplaum, kev ruaj khov thermal, kev sib raug zoo ntawm cov txheej txheem, thiab kev ntseeg siab mus sij hawm ntev. Raws li kev ua kom me me thiab qhov nyuaj nce ntxiv, cov teeb meem xws li electromigration thiab nanoscale tsis kam yog yuam kev lag luam los tsim cov ntaub ntawv tshiab thiab cov txheej txheem. Yog li ntawd, kev nkag siab txog kev siv cov hlau hauv semiconductors yog qhov tseem ceeb tsis yog rau cov ntaub ntawv thiab cov kws ua haujlwm txheej txheem xwb, tab sis kuj rau txhua tus neeg uas tab tom nrhiav kev nkag siab txog cov thev naus laus zis niaj hnub no yuav txuas ntxiv mus li cas.
