Kodi zigawo za epitaxial zimathandiza bwanji zida za semiconductor?

Chiyambi cha dzina lakuti epitaxial wafer

Choyamba, tiyeni titchule mfundo yaying'ono: kukonzekera wafer kumaphatikizapo maulalo awiri akuluakulu: kukonzekera substrate ndi njira ya epitaxial. Substrate ndi wafer wopangidwa ndi zinthu za semiconductor single crystal. Substrate imatha kulowa mwachindunji munjira yopanga wafer kuti ipange zida za semiconductor, kapena ikhoza kukonzedwa ndi njira za epitaxial kuti ipange ma wafer a epitaxial. Epitaxy imatanthauza njira yopangira wosanjikiza watsopano wa kristalo imodzi pa substrate imodzi ya kristalo yomwe yakonzedwa mosamala podula, kupukuta, kupukuta, ndi zina zotero. Kristalo yatsopano imodzi ikhoza kukhala chinthu chomwecho ndi substrate, kapena ikhoza kukhala chinthu chosiyana (chofanana) epitaxy kapena heteroepitaxy). Chifukwa chakuti gawo latsopano la kristalo limodzi limakula malinga ndi gawo la kristalo la gawo lapansi, limatchedwa gawo la epitaxial (makulidwe nthawi zambiri amakhala ma microns ochepa, potengera silicon mwachitsanzo: tanthauzo la kukula kwa silicon epitaxial lili pa gawo la kristalo limodzi la silicon lomwe lili ndi mawonekedwe enaake a kristalo. Gawo la kristalo lomwe lili ndi mawonekedwe abwino a lattice komanso kukana kosiyana ndi makulidwe okhala ndi mawonekedwe ofanana a kristalo monga gawo lapansi limakulitsidwa), ndipo gawo lokhala ndi gawo la epitaxial limatchedwa wafer wa epitaxial (wafer wa epitaxial = gawo la epitaxial + gawo lapansi). Chipangizocho chikapangidwa pa gawo la epitaxial, chimatchedwa epitaxy yabwino. Ngati chipangizocho chapangidwa pa gawo lapansi, chimatchedwa reverse epitaxy. Pakadali pano, gawo la epitaxial limangogwira ntchito yothandizira.

Wafa wopukutidwa

Njira zokulira za Epitaxial

Molecular beam epitaxy (MBE): Ndi ukadaulo wa semiconductor epitaxial growth womwe umachitika pansi pa vacuum conditions yapamwamba kwambiri. Mu njira iyi, zinthu zoyambira zimasanduka nthunzi ngati mtanda wa maatomu kapena mamolekyu kenako nkuyikidwa pa crystalline substrate. MBE ndi ukadaulo wolondola kwambiri komanso wowongoleredwa wa semiconductor thin film growth womwe ungathe kuwongolera molondola makulidwe a zinthu zomwe zasungidwa pamlingo wa atomu.
CVD yachilengedwe yachitsulo (MOCVD): Mu ndondomeko ya MOCVD, mpweya wachilengedwe wachitsulo ndi hydride mpweya wa N wokhala ndi zinthu zofunika umaperekedwa ku substrate pa kutentha koyenera, umadutsa mu reaction ya mankhwala kuti upange zinthu zofunikira za semiconductor, ndipo umayikidwa pa substrate, pomwe mankhwala otsala ndi zinthu zoyeserera zimatulutsidwa.
Nthunzi gawo epitaxy (VPE): Nthunzi gawo epitaxy ndi ukadaulo wofunikira womwe umagwiritsidwa ntchito kwambiri popanga zida za semiconductor. Mfundo yayikulu ndikunyamula nthunzi ya zinthu zoyambira kapena mankhwala mu mpweya wonyamulira, ndikuyika makhiristo pa substrate kudzera mu zochita za mankhwala.

Kodi njira ya epitaxy imathetsa mavuto otani?

Zipangizo zopanga makristalo okhaokha zokha ndi zomwe sizingakwaniritse zosowa zomwe zikukula popanga zipangizo zosiyanasiyana za semiconductor. Chifukwa chake, kukula kwa epitaxial, ukadaulo wocheperako wa kukula kwa zinthu zopanga makristalo amodzi, unapangidwa kumapeto kwa chaka cha 1959. Ndiye kodi ukadaulo wa epitaxy umapereka chiyani pakupititsa patsogolo zipangizo?

Kwa silicon, pamene ukadaulo wa kukula kwa silicon epitaxial unayamba, inali nthawi yovuta kwambiri popanga ma transistors a silicon omwe ali ndi ma frequency apamwamba komanso amphamvu kwambiri. Kuchokera pamalingaliro a mfundo za transistor, kuti mupeze ma frequency apamwamba komanso mphamvu yayikulu, mphamvu yowononga ya malo osonkhanitsira iyenera kukhala yayikulu ndipo kukana kwa mndandanda kuyenera kukhala kochepa, ndiko kuti, kutsika kwa mphamvu yokwanira kuyenera kukhala kochepa. Choyamba chimafuna kuti kukana kwa zinthu zomwe zili m'dera losonkhanitsira kukhale kwakukulu, pomwe chachiwiri chimafuna kuti kukana kwa zinthu zomwe zili m'dera losonkhanitsira kukhale kochepa. Madera awiriwa ndi otsutsana. Ngati makulidwe a zinthu zomwe zili m'dera losonkhanitsira achepetsedwa kuti achepetse kukana kwa mndandanda, wafer wa silicon udzakhala woonda kwambiri komanso wofooka kuti usakonzedwe. Ngati kukana kwa zinthuzo kwachepetsedwa, zidzatsutsana ndi chofunikira choyamba. Komabe, chitukuko cha ukadaulo wa epitaxial chapambana. Kuthetsa vutoli.

Yankho: Pangani chipangizo cha epitaxial cholimba kwambiri pa substrate yolimba kwambiri, ndipo pangani chipangizocho pa epitaxial layer. Chida ichi cha epitaxial cholimba kwambiri chimatsimikizira kuti chubucho chili ndi magetsi ambiri owonongeka, pomwe substrate yolimba kwambiri imachepetsanso kukana kwa substrate, potero imachepetsa kutsika kwa magetsi ochulukirapo, potero kuthetsa kutsutsana pakati pa awiriwa.

Kuphatikiza apo, ukadaulo wa epitaxy monga epitaxy ya gawo la nthunzi ndi epitaxy ya gawo lamadzimadzi ya GaAs ndi zida zina za III-V, II-VI ndi ma molecular compound semiconductor nawonso apangidwa kwambiri ndipo akhala maziko a zida zambiri za microwave, zida za optoelectronic, mphamvu. Ndi ukadaulo wofunikira kwambiri popanga zida, makamaka kugwiritsa ntchito bwino kwa ukadaulo wa molecular beam ndi metal organic vapor phase epitaxy mu zigawo zoonda, superlattices, quantum wells, strained superlattices, ndi atomic-level thin-layer epitaxy, yomwe ndi sitepe yatsopano mu kafukufuku wa semiconductor. Kukula kwa "energy belt engineering" m'munda kwakhazikitsa maziko olimba.

Mu ntchito zenizeni, zipangizo za semiconductor za bandgap nthawi zambiri zimapangidwa pa epitaxial layer, ndipo silicon carbide wafer yokha imagwira ntchito ngati substrate yokha. Chifukwa chake, kuwongolera kwa epitaxial layer ndi gawo lofunikira kwambiri mumakampani a semiconductor a bandgap.

Maluso 7 akuluakulu muukadaulo wa epitaxy

1. Magawo a epitaxial okhwima kwambiri (otsika) akhoza kulimidwa m'malo okhwima kwambiri (otsika).
2. Gawo la epitaxial la mtundu wa N (P) likhoza kukulitsidwa pa gawo la mtundu wa P (N) kuti lipange mgwirizano wa PN mwachindunji. Palibe vuto lobwezera ndalama mukamagwiritsa ntchito njira yofalitsira kupanga mgwirizano wa PN pa gawo limodzi la kristalo.
3. Kuphatikiza ndi ukadaulo wa mask, kukula kwa epitaxial kosankhidwa kumachitika m'malo osankhidwa, zomwe zimapangitsa kuti pakhale zinthu zopangira ma circuits ophatikizika ndi zida zokhala ndi mapangidwe apadera.
4. Mtundu ndi kuchuluka kwa doping kungasinthidwe malinga ndi zosowa panthawi ya kukula kwa epitaxial. Kusintha kwa kuchuluka kwa doping kungakhale kusintha kwadzidzidzi kapena kusintha pang'onopang'ono.
5. Imatha kukula mitundu yosiyanasiyana, yokhala ndi zigawo zambiri, yokhala ndi zigawo zambiri komanso yokhala ndi zigawo zoonda kwambiri zokhala ndi zigawo zosiyanasiyana.
6. Kukula kwa epitaxial kumatha kuchitika kutentha kotsika kuposa malo osungunuka a zinthuzo, kuchuluka kwa kukula kumatha kulamulidwa, ndipo kukula kwa epitaxial kwa makulidwe a atomiki kumatha kuchitika.
7. Imatha kumera zinthu za kristalo imodzi zomwe sizingakokedwe, monga GaN, zigawo za kristalo imodzi za mankhwala atatu ndi a quaternary, ndi zina zotero.