Ƙa'idodin Fasaha da Tsari na LED Epitaxial Wafers

Daga ka'idar aiki na LEDs, a bayyane yake cewa kayan wafer na epitaxial shine ainihin ɓangaren LED. A haƙiƙa, maɓalli na optoelectronic maɓalli kamar tsayin igiya, haske, da ƙarfin wuta na gaba ana ƙaddara su ta hanyar kayan epitaxial. Fasahar wafer na Epitaxial da kayan aiki suna da mahimmanci ga tsarin masana'antu, tare da Ƙarfe-Organic Chemical Vapor Deposition (MOCVD) shine hanya ta farko don haɓaka siraran sirara guda-crystal na III-V, II-VI mahadi, da gaminsu. A ƙasa akwai wasu halaye na gaba a fasahar wafer epitaxial LED.

1. Inganta Tsarin Ci gaban Matakai Biyu

A halin yanzu, samar da kasuwanci yana amfani da tsarin ci gaban matakai biyu, amma yawan adadin abubuwan da za'a iya lodawa lokaci ɗaya yana iyakance. Yayin da tsarin 6-wafer ya balaga, injinan da ke sarrafa wafers 20 har yanzu suna kan haɓakawa. Ƙara yawan wafers sau da yawa yana haifar da rashin daidaituwa a cikin sassan epitaxial. Abubuwan da ke faruwa a gaba za su mayar da hankali kan hanyoyi guda biyu:

• Haɓaka fasahohin da ke ba da damar yin lodin abubuwa masu yawa a cikin ɗaki ɗaya na amsawa, yana mai da su mafi dacewa don samarwa mai girma da rage farashi.
• Ci gaba mai sarrafa kansa sosai, kayan aikin wafer guda ɗaya mai maimaitawa.

2. Fasahar Haɗaɗɗen Haɗaɗɗen Mataki na Epitax (HVPE).

Wannan fasaha yana ba da damar haɓakar saurin girma na fina-finai masu kauri tare da ƙarancin raguwa, wanda zai iya zama maƙasudin haɓakar haɓakar homoepitaxial ta amfani da wasu hanyoyin. Bugu da ƙari, fina-finan GaN da aka rabu da su na iya zama madadin ga babban guntu na GaN guda-crystal. Koyaya, HVPE yana da koma baya, kamar wahala a cikin daidaitaccen sarrafa kauri da iskar gas mai lalata da ke hana ci gaba a cikin tsabtar kayan GaN.

Si-doped HVPE-GAN

(a) Tsarin Si-doped HVPE-GaN reactor; (b) Hoton 800 μm- kauri Si-doped HVPE-GAN;

(c) Rarraba ƙaddamarwar jigilar kaya kyauta tare da diamita na Si-doped HVPE-GaN

3. Zaɓin Ci gaban Epitaxial ko Fasahar Ci gaban Epitaxial na Layi

Wannan dabarar na iya ƙara rage ɗimbin rarrabuwar kawuna da haɓaka ingancin kristal na GaN epitaxial layers. Tsarin ya ƙunshi:

• Ajiye Layer GaN akan madaidaicin madauri (sapphire ko SiC).
• Ajiye abin rufe fuska na SiO₂ polycrystalline a saman.
• Yin amfani da hotunan hoto da etching don ƙirƙirar tagogin GaN da SiO₂ abin rufe fuska.A lokacin girma na gaba, GaN na farko yana girma a tsaye a cikin tagogin sannan kuma a kaikaice akan filayen SiO₂.

GaN-on-Sapphire wafer na XKH

4. Fasahar Pendeo-Epitoxy

Wannan hanya tana rage lahani na lattice da ke haifar da rashin daidaituwa da rashin daidaituwa na thermal tsakanin ma'auni da Layer epitaxial, yana ƙara haɓaka ingancin GaN crystal. Matakan sun haɗa da:

• Girman GaN epitaxial Layer a kan madaidaicin madauri (6H-SiC ko Si) ta amfani da tsari mai mataki biyu.
• Yin zaɓaɓɓen etching na epitaxial Layer zuwa ƙasa, ƙirƙirar ginshiƙi mai canzawa (GaN/buffer/ substrate) da tsarin maɓalli.
• Haɓaka ƙarin yadudduka na GaN, waɗanda ke shimfiɗa a gefe daga bangon ginshiƙan GaN na asali, an dakatar da su akan ramuka.Tunda ba a yi amfani da abin rufe fuska ba, wannan yana guje wa hulɗa tsakanin GaN da kayan abin rufe fuska.

XKH's GaN-on-Silicon wafer

5. Haɓakawa na Short-Wavelength UV LED Epitaxial Materials

Wannan yana shimfiɗa tushe mai ƙarfi don LEDs masu farin ciki na tushen phosphor UV. Yawancin phosphor masu inganci na iya jin daɗin hasken UV, suna ba da ingantaccen haske fiye da tsarin YAG: Ce na yanzu, don haka haɓaka aikin farin LED.

6. Fasahar Chip Multi-Quantum Well (MQW).

A cikin sifofin MQW, ƙazanta daban-daban suna ƙara haɓaka yayin haɓakar shimfidar haske don ƙirƙirar rijiyoyin ƙididdiga daban-daban. Sake haɗa hotunan photon da ke fitowa daga waɗannan rijiyoyin suna haifar da farin haske kai tsaye. Wannan hanyar tana inganta ingantaccen haske, rage farashi, da sauƙaƙe marufi da sarrafa da'ira, kodayake yana gabatar da ƙalubale na fasaha.

7. Haɓaka Fasahar Sake Amfani da Hoto

A cikin Janairu 1999, Sumitomo na Japan ya haɓaka farin LED ta amfani da kayan ZnSe. Fasahar ta ƙunshi haɓaka fim ɗin CdZnSe na bakin ciki akan madaidaicin kintinkiri na ZnSe guda ɗaya. Lokacin da aka kunna fim ɗin, fim ɗin yana fitar da haske shuɗi, wanda ke hulɗa tare da ma'aunin ZnSe don samar da ƙarin haske mai rawaya, yana haifar da farin haske. Hakazalika, Cibiyar Bincike ta Photonics na Jami'ar Boston ta tattara mahallin semiconductor na AlInGaP akan shuɗin GaN-LED don samar da farin haske.

8. LED Epitaxial Wafer Tsarin Guda

① Epitaxial Wafer Fabrication:
Substrate → Tsarin tsari → Ci gaban Layer Layer → N-nau'in GaN ci gaban Layer → MQW haɓaka mai haske mai haske → Nau'in GaN Girman Layer → Annealing → Gwaji (photoluminescence, X-ray) → Epitaxial wafer

② Aikin Chip:
Epitaxial wafer → Tsarin mashin da ƙirƙira → Photolithography → Ion etching → Nau'in lantarki na nau'in N-nau'in lantarki (ajiya, annealing, etching) → nau'in lantarki na nau'in P (zubawa, annealing, etching) → Dicing → Binciken guntu da grading.

ZMSH's GaN-on-SiC wafer