Imigaqo yoBugcisa kunye neenkqubo zeeWafers ze-LED Epitaxial

Ukusuka kumgaqo wokusebenza kwee-LED, kuyacaca ukuba izinto ze-epitaxial wafer zezona zinto ziphambili kwi-LED. Enyanisweni, iiparameter eziphambili ze-optoelectronic ezifana nobude be-wavelength, ukukhanya, kunye ne-forward voltage zixhomekeke kakhulu kwizinto ze-epitaxial. Itekhnoloji ye-epitaxial wafer kunye nezixhobo zibalulekile kwinkqubo yokuvelisa, kunye ne-Metal-Organic Chemical Vapor Deposition (MOCVD) yeyona ndlela iphambili yokukhulisa iileya ezincinci zekristale enye zeekhompawundi ze-III-V, II-VI, kunye nee-alloys zazo. Apha ngezantsi kukho ezinye zeendlela ezizayo kwitekhnoloji ye-epitaxial wafer ye-LED.

1. Ukuphuculwa kweNkqubo yoKhulo oluneZinyathelo ezibini

Okwangoku, imveliso yorhwebo isebenzisa inkqubo yokukhula enamanyathelo amabini, kodwa inani lee-substrates ezinokulayishwa ngaxeshanye lilinganiselwe. Nangona iinkqubo ze-6-wafer zivuthiwe, oomatshini abaphatha malunga ne-20 wafers basaphuhliswa. Ukwandisa inani lee-wafers kudla ngokukhokelela ekungalinganini ngokwaneleyo kwiileya ze-epitaxial. Uphuhliso lwexesha elizayo luya kugxila kwiindlela ezimbini:

• Ukuphuhlisa ubuchwepheshe obuvumela ukulayisha ii-substrates ezingaphezulu kwigumbi lokusabela elinye, nto leyo eyenza zifaneleke ngakumbi kwimveliso enkulu kunye nokunciphisa iindleko.
• Izixhobo ze-wafer enye ezisebenza ngokuzenzekelayo neziphinda-phindwayo ziphucula kakhulu.

2. Iteknoloji ye-Hydride Vapor Phase Epitaxy (HVPE)

Le teknoloji ivumela ukukhula ngokukhawuleza kweefilimu ezixineneyo ezinoxinano oluphantsi lokusasazeka, ezinokusebenza njengeziseko zokukhula kwe-homoepitaxial kusetyenziswa ezinye iindlela. Ukongeza, iifilimu ze-GaN ezahlulwe kwisiseko zinokuba zezinye iindlela endaweni yeetships ze-GaN single-crystal. Nangona kunjalo, i-HVPE ineengxaki, ezifana nobunzima ekulawuleni ubukhulu obuchanekileyo kunye neegesi zempendulo erhabaxa ezithintela ukuphuculwa okungakumbi kokucoceka kwezinto ze-GaN.

I-HVPE-GaN exutywe ne-Si-doped

(a) Ulwakhiwo lwe-reactor ye-Si-doped HVPE-GaN; (b) Umfanekiso we-800 μm- ubukhulu be-Si-doped HVPE-GaN;

(c) Ukusasazwa koxinzelelo olukhululekileyo lwe-carrier kububanzi be-Si-doped HVPE-GaN

3. Ukukhula kwe-Epitaxial okuKhethiweyo okanye iTekhnoloji yokukhula kwe-Epitaxial esecaleni

Le ndlela inokunciphisa ngakumbi uxinano lwe-dislocation kwaye iphucule umgangatho wekristale wee-GaN epitaxial layers. Le nkqubo ibandakanya:

• Ukubeka umaleko weGaN kwi-substrate efanelekileyo (isafire okanye iSiC).
• Ukubeka umaleko wemaski ye-polycrystalline SiO₂ phezulu.
• Ukusebenzisa i-photolithography kunye nokukrola ukwenza iifestile zeGaN kunye nemicu yemaski yeSiO₂.Ngexesha lokukhula okulandelayo, iGaN iqala ikhule ngokuthe nkqo kwiifestile ize ikhule emacaleni phezu kwemicu yeSiO₂.

I-wafer ye-XKH yeGaN-on-Sapphire

4. Itekhnoloji yePendeo-Epitaxy

Le ndlela inciphisa kakhulu iziphene ze-lattice ezibangelwa yi-lattice kunye nokungafani kobushushu phakathi kwe-substrate kunye ne-epitaxial layer, nto leyo ephucula ngakumbi umgangatho wekristale yeGaN. Amanyathelo aquka:

• Ukukhulisa umaleko we-epitaxial we-GaN kwi-substrate efanelekileyo (6H-SiC okanye i-Si) kusetyenziswa inkqubo enamanyathelo amabini.
• Ukwenza ukukrola okukhethiweyo kwe-epitaxial layer ukuya kwi-substrate, ukudala i-alternating pillar (GaN/buffer/substrate) kunye nezakhiwo ze-trench.
• Ukwandisa iileya zeGaN ezongezelelweyo, ezisuka ecaleni kweendonga zeentsika zeGaN zokuqala, ezixhonywe phezu kwemisele.Ekubeni kungekho mask isetyenziswayo, oku kuthintela ukudibana phakathi kwezinto zeGaN kunye nemaski.

I-wafer ye-XKH yeGaN-on-Silicon

5. Uphuhliso lwezixhobo ze-UV LED Epitaxial ze-Short-Wavelength

Oku kubeka isiseko esiqinileyo see-LED ezimhlophe ezisekelwe kwi-UV-active phosphor-based. Ii-phosphor ezininzi ezisebenzayo kakhulu zinokuvuselelwa kukukhanya kwe-UV, zibonelela ngokusebenza kakuhle kokukhanya kunenkqubo yangoku ye-YAG:Ce, ngaloo ndlela ziphucula ukusebenza kwe-LED emhlophe.

6. Ubuchwepheshe beChip yeMulti-Quantum Well (MQW)

Kwizakhiwo ze-MQW, ukungcola okwahlukeneyo kuyaxutywa ngexesha lokukhula komaleko okhupha ukukhanya ukuze kudalwe imigodi eyahlukeneyo ye-quantum. Ukuhlanganiswa kwakhona kwee-photons ezikhutshwa kwezi migodi kuvelisa ukukhanya okumhlophe ngokuthe ngqo. Le ndlela iphucula ukusebenza kakuhle kokukhanya, inciphisa iindleko, kwaye yenza lula ukupakisha kunye nolawulo lwesekethe, nangona inika imingeni emikhulu yobugcisa.

7. Uphuhliso lweTekhnoloji “yokuRisayikilisha iPhoton”

NgoJanuwari 1999, iSumitomo yaseJapan yavelisa i-LED emhlophe isebenzisa izinto ze-ZnSe. Le teknoloji ibandakanya ukukhulisa ifilimu encinci ye-CdZnSe kwi-substrate ye-ZnSe single-crystal. Xa ifakwe umbane, ifilimu ikhupha ukukhanya okuluhlaza okwesibhakabhaka, okusebenzisana ne-substrate ye-ZnSe ukuvelisa ukukhanya okutyheli okuhambelanayo, okubangela ukukhanya okumhlophe. Ngokufanayo, iZiko loPhando lwePhotonics kwiYunivesithi yaseBoston labeka i-AlInGaP semiconductor compound kwi-blue GaN-LED ukuvelisa ukukhanya okumhlophe.

8. Inkqubo yokuHamba kweWafer ye-LED Epitaxial

① Ukwenziwa kweWafer ye-Epitaxial:
I-substrate → Uyilo lwesakhiwo → Ukukhula komaleko we-Buffer → Ukukhula komaleko we-GaN yohlobo lwe-N → Ukukhula komaleko okhupha ukukhanya kwe-MQW → Ukukhula komaleko we-GaN yohlobo lwe-P → Ukufakwa kwe-Annealing → Uvavanyo (i-photoluminescence, i-X-ray) → I-Epitaxial wafer

② Ukwenziwa kweetships:
I-Epitaxial wafer → Uyilo kunye nokwenziwa kwemaski → I-Photolithography → Ukukrola i-Ion → I-electrode yohlobo lwe-N (ukubeka, ukuqhobosha, ukukrola) → I-electrode yohlobo lwe-P (ukubeka, ukuqhobosha, ukukrola) → Ukukrola → Ukuhlolwa kwe-chip kunye nokubeka amanqaku.

I-wafer ye-GaN-on-SiC ye-ZMSH