Amahame n'imikorere bya tekiniki bya LED Epitaxial Wafers

Dukurikije ihame ry’imikorere ya LED, biragaragara ko ibikoresho bya epitaxial wafer ari byo bigize LED. Mu by’ukuri, ibipimo by’ingenzi bya optoelectronic nka wavelength, urumuri, na voltage y’imbere bigenwa ahanini n’ibikoresho bya epitaxial. Ikoranabuhanga rya epitaxial wafer n’ibikoresho ni ingenzi mu gikorwa cyo kuyikora, aho Metal-Organic Chemical Vapor Deposition (MOCVD) ari bwo buryo bw’ibanze bwo gukura urwego rworoshye rwa III-V, II-VI, hamwe n’ibindi bikoresho byayo. Hasi aha hari bimwe mu bizagenda mu ikoranabuhanga rya LED epitaxial wafer.

1. Kunoza inzira yo gukura mu ntambwe ebyiri

Muri iki gihe, umusaruro w’ubucuruzi ukoresha inzira yo gukura mu ntambwe ebyiri, ariko umubare w’ibikoresho bishobora gushyirwamo ibintu icyarimwe ni muto. Nubwo sisitemu 6 za wafer zimaze gukura, imashini zikora wafer zigera kuri 20 ziracyari mu iterambere. Kongera umubare w’ibikoresho bya wafer akenshi bituma bidakwirakwira neza mu byiciro bya epitaxial. Iterambere ry’ejo hazaza rizibanda ku byerekezo bibiri:

• Guteza imbere ikoranabuhanga ryemerera gushyira ibintu byinshi mu cyumba kimwe cy’ibisubizo, bigatuma biba byiza cyane mu gukora ibintu byinshi no kugabanya ikiguzi.
• Guteza imbere ibikoresho byikora cyane kandi bishobora gusubiramo ibikoresho bya wafer imwe.

2. Ikoranabuhanga rya Hydride Vapor Phase Epitaxy (HVPE)

Iri koranabuhanga rituma habaho gukura vuba kwa firime nini zifite ubucucike buke bwo kwangirika, zishobora gukoreshwa nk'ibikoresho byo gukura kwa homoepitaxial hakoreshejwe ubundi buryo. Byongeye kandi, firime za GaN zitandukanyijwe n'izishobora kuba ubundi buryo bwo gusimbura utubumbe twa GaN twinshi. Ariko, HVPE ifite ingorane, nko kugorwa no kugenzura neza ubunini n'imyuka yangiza ibuza iterambere ry'ibikoresho bya GaN.

HVPE-GaN ikoresha Si-doped

(a) Imiterere ya reactor ya Si-doped HVPE-GaN; (b) Ishusho ya Si-doped HVPE-GaN ifite ubugari bwa 800 μm;

(c) Gukwirakwiza ubunini bw'ibinyabiziga ku mpande z'umurambararo wa Si-doped HVPE-GaN

3. Ikoranabuhanga ryo Gukura mu Isoko rya Epitaxial cyangwa Ikoranabuhanga ryo Gukura mu Isoko rya Epitaxial

Ubu buryo bushobora kugabanya cyane ubucucike bw'impinduka no kunoza ubwiza bwa kristale ya GaN epitaxial layers. Ubu buryo bukubiyemo:

• Gushyira urwego rwa GaN ku kintu gikwiye (safira cyangwa SiC).
• Gushyira agace ka polycrystalline SiO₂ mask hejuru.
• Gukoresha fotolithography no gushushanya kugira ngo ukore amadirishya ya GaN na SiO₂ mask strips.Mu gihe cyo gukura nyuma, GaN ibanza gukura ihagaze mu madirishya hanyuma ikagera ku ruhande rw'imirongo ya SiO₂.

Umugati wa XKH wa GaN-on-Sapphire

4. Ikoranabuhanga rya Pendeo-Epitaxy

Ubu buryo bugabanya cyane inenge za lattice ziterwa na lattice no kudahuza neza kw'ubushyuhe hagati ya substrate na epitaxial layer, bikongera ubwiza bwa GaN crystal. Intambwe zirimo:

• Gutera urwego rwa GaN epitaxial ku gice gikwiye (6H-SiC cyangwa Si) hakoreshejwe inzira y'intambwe ebyiri.
• Gukora isesengura ry’urwego rwa epitaxial kugeza ku gice cy’ubutaka, bigakora inkingi isimburana (GaN/buffer/substrate) n’imiterere y’imiyoboro.
• Gutera izindi ngingo za GaN, zihera ku ruhande rw'inkuta z'inkingi za GaN za mbere, zimanitse hejuru y'imiyoboro.Kubera ko nta gapfukamunwa gakoreshwa, ibi birinda ko GaN n'ibikoresho bya gapfukamunwa bihura.

Umugati wa XKH wa GaN-on-Silicon

5. Iterambere ry'ibikoresho bya epitaxial bya UV LED bifite uburebure bugufi

Ibi bishyiraho urufatiro rukomeye rwa LED z'umweru zishingiye kuri phosphor zikoresha UV. Phosphor nyinshi zikoresha UV neza zishobora gukururwa n'urumuri rwa UV, zigatanga urumuri rwinshi kurusha sisitemu ya YAG:Ce iriho ubu, bityo zigateza imbere imikorere ya LED z'umweru.

6. Ikoranabuhanga rya Chip ya Multi-Quantum Well (MQW)

Mu miterere ya MQW, imyanda itandukanye irashyirwa mu gihe cyo gukura k'urwego rutanga urumuri kugira ngo habeho amariba atandukanye ya quantum. Gusubiramo fotoni zisohoka muri ayo mariba bitanga urumuri rwera mu buryo butaziguye. Ubu buryo bwongera imikorere myiza y'urumuri, bugabanya ikiguzi, kandi bworoshya uburyo bwo gupakira no kugenzura uruziga, nubwo butanga imbogamizi zikomeye mu bya tekiniki.

7. Iterambere ry'ikoranabuhanga rya "Photon Recycling"

Muri Mutarama 1999, Sumitomo yo mu Buyapani yakoze LED y'umweru ikoresheje ibikoresho bya ZnSe. Iri koranabuhanga rikubiyemo gukura firime nto ya CdZnSe ku gikoresho cya ZnSe cy'ubutare bumwe. Iyo firime ikoreshejwe amashanyarazi, itanga urumuri rw'ubururu, rukorana na substrate ya ZnSe kugira ngo ikore urumuri rw'umuhondo rwuzuzanya, bigatuma habaho urumuri rw'umweru. Mu buryo nk'ubwo, Ikigo cy'Ubushakashatsi cya Kaminuza ya Boston cyashyize imvange ya AlInGaP ku gikoresho cya GaN-LED cy'ubururu kugira ngo ikore urumuri rw'umweru.

8. Uburyo bwo gusohora urumuri rwa LED Epitaxial Wafer

① Gukora Wafer ya Epitaxial:
Substrate → Igishushanyo mbonera cy'inyubako → Gukura kw'urwego rwa Buffer → Gukura kw'urwego rwa GaN rwo mu bwoko bwa N → Gukura kw'urwego rwa MQW rutanga urumuri → Gukura kw'urwego rwa GaN rwo mu bwoko bwa P → Annealing → Isuzuma (photoluminescence, X-ray) → Epitaxial wafer

② Gukora Chips:
Epitaxial wafer → Igishushanyo mbonera n'uburyo bwo gukora mask → Fotolithography → Ion etching → Electrode yo mu bwoko bwa N (gushyiramo, gufunga, gukata) → Electrode yo mu bwoko bwa P (gushyiramo, gukanda, gukata) → Gukata → Gusuzuma no gupima Chip.

Agace ka ZMSH ka GaN-on-SiC