Iyini i-chip ye-LED? Ngakho yiziphi izici zayo? Inhloso eyinhloko yokwenziwa kwama-chip e-LED iwukwenza ama-electrode othintana naye we-ohm asebenzayo futhi anokwethenjelwa, kanye nokuhlangabezana nokwehla kwamandla kagesi amancane phakathi kwezinto ezixhumekayo nokuhlinzeka ngamaphedi okucindezela ezintanjeni zokudayiswa, kuyilapho kukhulisa inani lokukhipha ukukhanya. Inqubo ye-cross film ngokuvamile isebenzisa indlela yokuhwamuka kwe-vacuum. Ngaphansi kwe-vacuum ephezulu ye-4Pa, impahla incibilikiswa ngokushisisa kokumelana noma indlela yokushisa ye-electron beam bombardment, futhi i-BZX79C18 iguqulwa ibe umhwamuko wensimbi futhi ifakwe phezu kwempahla ye-semiconductor ngaphansi kwengcindezi ephansi.
Izinsimbi ezisetshenziswa kakhulu zohlobo lwe-P zihlanganisa ama-alloys afana ne-AuBe ne-AuZn, kuyilapho insimbi yokuxhumana eseceleni kwe-N ivame ukwenziwa nge-AuGeNi alloy. Isendlalelo se-alloy esakhiwe ngemva kokumbozwa sidinga ukudalulwa ngangokunokwenzeka endaweni ye-luminescent ngokusebenzisa inqubo ye-photolithography, ukuze ungqimba olusele lwe-alloy lukwazi ukuhlangabezana nezidingo zama-electrode othintana nama-ohm aphansi asebenzayo kanye nama-solder wire pressure pads. Ngemuva kokuthi inqubo ye-photolithography isiqediwe, nayo idinga ukudlula inqubo ye-alloying, evame ukuqhutshwa ngaphansi kokuvikelwa kwe-H2 noma i-N2. Isikhathi kanye nezinga lokushisa kwe-alloying ngokuvamile kunqunywa izici ezifana nezici zezinto zokwakha ze-semiconductor kanye nesimo somlilo we-alloy. Yiqiniso, uma izinqubo ze-electrode eziluhlaza okwesibhakabhaka nezinye ze-chip ziyinkimbinkimbi, kuyadingeka ukwengeza ukukhula kwefilimu ye-passivation, izinqubo ze-plasma etching, njll.
Enqubweni yokukhiqiza ama-chips e-LED, yiziphi izinqubo ezinomthelela omkhulu ekusebenzeni kwawo kwe-optoelectronic?
Ngokuvamile, ngemva kokuphothulwa kokukhiqizwa kwe-epitaxial ye-LED, ukusebenza kwayo okuyinhloko kagesi sekuqediwe, futhi ukukhiqizwa kwama-chip akuguquli imvelo yakhona yokukhiqiza. Kodwa-ke, izimo ezingalungile phakathi nenqubo yokumboza kanye ne-alloying zingabangela ukuthi imingcele ethile kagesi ibe mpofu. Isibonelo, amazinga okushisa aphansi noma aphezulu e-alloying angabangela ukuthintana okungalungile kwe-Ohmic, okuyimbangela eyinhloko yokwehla kwamandla kagesi aya phambili aphezulu i-VF ekukhiqizeni ama-chip. Ngemva kokusika, ezinye izinqubo zokugqwala emaphethelweni e-chip zingaba usizo ekuthuthukiseni ukuvuza okuphambene kwe-chip. Lokhu kungenxa yokuthi ngemva kokusika ngensingo yesondo lokugaya idayimane, kuzoba nenqwaba yezinsalela nempushana emaphethelweni e-chip. Uma lezi zinhlayiya zinamathela ekuhlanganeni kwe-PN kwe-chip ye-LED, zizobangela ukuvuza kukagesi ngisho nokuphuka. Ngaphezu kwalokho, uma i-photoresist engaphezulu kwe-chip ingahlutshiwe ngokuhlanzekile, izodala ubunzima phambi kwe-soldering kanye ne-soldering ebonakalayo. Uma ingemuva, izophinde ibangele ukwehla komfutho ophezulu. Ngesikhathi senqubo yokukhiqiza ama-chip, ukwakheka kwe-surface roughening kanye nezakhiwo ze-trapezoidal zingasetshenziswa ukwandisa amandla okukhanya.
Kungani ama-chips e-LED adinga ukuhlukaniswa ngamasayizi ahlukene? Uyini umthelela wosayizi ekusebenzeni kwe-LED optoelectronic?
Ama-chips e-LED angahlukaniswa abe ama-chips anamandla aphansi, ama-chips amandla aphakathi nendawo, nama-chips anamandla aphezulu ngokusekelwe emandleni. Ngokwezidingo zamakhasimende, ingahlukaniswa ngezigaba ezifana neleveli yeshubhu eyodwa, ileveli yedijithali, ileveli ye-matrix yamachashazi, nokukhanya kokuhlobisa. Ngokuqondene nosayizi othize we-chip, kuncike ezingeni langempela lokukhiqiza labakhiqizi abahlukene be-chip futhi azikho izidingo ezithile. Uma nje inqubo idluliswa, i-chip ingakhuphula ukuphuma kweyunithi futhi inciphise izindleko, futhi ukusebenza kwe-photoelectric ngeke kube nezinguquko eziyisisekelo. Eyamanje esetshenziswa i-chip empeleni ihlobene nokuminyana kwamanje okugeleza ku-chip. I-chip encane isebenzisa i-current encane, kuyilapho i-chip enkulu isebenzisa yamanje kakhulu, futhi ukuminyana kweyunithi yayo kwamanje kuyafana. Uma kucatshangelwa ukuthi ukuchithwa kokushisa kuyinkinga eyinhloko ngaphansi kwamandla aphezulu, ukusebenza kahle kwawo okukhanyayo kuphansi kunalokho okungaphansi kwamandla aphansi. Ngakolunye uhlangothi, njengoba indawo ikhula, ukumelana komzimba we-chip kuzokwehla, okuholela ekunciphiseni kwe-voltage conduction phambili.

Iyiphi indawo ejwayelekile yama-chips anamandla aphezulu e-LED? Kungani?
Ama-chips anamandla amakhulu e-LED asetshenziselwa ukukhanya okumhlophe ngokuvamile abonakala emakethe cishe ku-40mil, futhi amandla asetshenziselwa ama-chips anamandla ngokuvamile abhekisela kumandla kagesi angaphezu kuka-1W. Ngenxa yokusebenza kahle kwe-quantum ngokuvamile kungaphansi kuka-20%, amandla kagesi amaningi aguqulwa abe amandla ashisayo, ngakho-ke ukuchithwa kokushisa kubalulekile kuma-chips amandla aphezulu, okudinga ukuthi abe nendawo enkulu.
Yiziphi izidingo ezihlukene zobuchwepheshe be-chip kanye nemishini yokucubungula yokukhiqiza izinto ze-GaN epitaxial uma kuqhathaniswa ne-GaP, i-GaAs, ne-InGaAlP? Kungani?
Ama-substrates ama-LED ajwayelekile abomvu naphuzi chips kanye nokukhanya okuphezulu kwe-quaternary abomvu naphuzi kokubili asebenzisa izinto ezihlanganisiwe zesemiconductor njenge-GaP nama-GaAs, futhi ngokuvamile angenziwa abe ama-substrates ohlobo lwe-N. Kusetshenziswa inqubo emanzi ye-photolithography, futhi kamuva ukusika kube ama-chips kusetshenziswa izindwani zamasondo okugaya idayimane. I-chip eluhlaza okwesibhakabhaka eyenziwe ngezinto ze-GaN isebenzisa i-sapphire substrate. Ngenxa yemvelo yokuvikela ye-sapphire substrate, ayikwazi ukusetshenziswa njenge-electrode ye-LED. Ngakho-ke, womabili ama-electrode e-P/N kufanele enziwe endaweni ye-epitaxial ngokuqoshwa okomile futhi ezinye izinqubo zokudlula kufanele zenziwe. Ngenxa yokuqina kwesafire, kunzima ukusika ama-chips ngezinsimbi zamasondo okugaya idayimane. Inqubo yokukhiqiza yayo ngokuvamile iyinkimbinkimbi kakhulu kunaleyo yezinto ze-GaP ne-GaAsIzibani zezikhukhula ze-LED.

Iyini isakhiwo nezici ze-chip "ebonakalayo ye-electrode"?
I-electrode ebizwa ngokuthi i-transparent kufanele ikwazi ukuqhuba ugesi futhi ikwazi ukudlulisa ukukhanya. Le nto manje isetshenziswa kabanzi ezinqubweni zokukhiqiza i-crystal ewuketshezi, futhi igama layo yi-indium tin oxide, efushanisiwe njenge-ITO, kodwa ayikwazi ukusetshenziswa njenge-solder pad. Uma wenza, kudingekile ukuthi uqale ulungiselele i-electrode ye-ohmic ebusweni be-chip, bese uvala ubuso ngesendlalelo se-ITO, bese ufaka ungqimba lwamaphedi e-solder ebusweni be-ITO. Ngale ndlela, owamanje owehlayo ocingweni oluholayo lusatshalaliswa ngokulinganayo kulo lonke ungqimba lwe-ITO ku-electrode yokuxhumana ye-ohmic ngayinye. Ngesikhathi esifanayo, ngenxa yenkomba ye-refractive ye-ITO phakathi komoya kanye nenkomba ye-refractive ye-epitaxial material, i-angle yokukhanya ingandiswa, futhi ukukhanya okukhanyayo kungandiswa.

Kuyini ukuthuthukiswa okujwayelekile kobuchwepheshe be-chip bokukhanyisa kwe-semiconductor?
Ngokuthuthukiswa kobuchwepheshe be-semiconductor LED, ukusetshenziswa kwayo emkhakheni wokukhanyisa kuyanda, ikakhulukazi ukuvela kwe-LED emhlophe, eye yaba isihloko esishisayo ekukhanyeni kwe-semiconductor. Kodwa-ke, ama-chips abalulekile kanye nobuchwepheshe bokupakisha kusadinga ukuthuthukiswa, futhi ukuthuthukiswa kwama-chips kufanele kugxile kumandla aphezulu, ukusebenza kahle kokukhanya okuphezulu, nokunciphisa ukumelana nokushisa. Ukwandisa amandla kusho ukwandisa ukusetshenziswa kwamanje kwe-chip, futhi indlela eqondile kakhulu ukukhulisa usayizi we-chip. Ama-chips asetshenziswa kakhulu amandla aphezulu acishe abe ngu-1mm x 1mm, asebenzisa amandla angu-350mA. Ngenxa yokwanda kwamandla okusetshenziswa, ukuchithwa kokushisa sekuyinkinga evelele. Manje, indlela yokuguqulwa kwe-chip ixazulule le nkinga ngokuyisisekelo. Ngokuthuthukiswa kobuchwepheshe be-LED, ukusetshenziswa kwayo emkhakheni wokukhanyisa kuzobhekana namathuba nezinselele ezingakaze zibonwe ngaphambili.
Yini i-chip ehlanekezelwe? Siyini ukwakheka kwayo futhi yiziphi izinzuzo zayo?
Ama-LED aluhlaza okwesibhakabhaka ngokuvamile asebenzisa ama-substrates e-Al2O3, anokuqina okuphezulu, ukuguquguquka okuphansi kwe-thermal, kanye nokuhamba kukagesi. Uma isakhiwo esihlelekile sisetshenziswa, ngakolunye uhlangothi, sizoletha izinkinga eziphikisana ne-static, futhi ngakolunye uhlangothi, ukuchithwa kokushisa kuzoba yinkinga enkulu ngaphansi kwezimo eziphezulu zamanje. Ngesikhathi esifanayo, ngenxa ye-electrode enhle ebheke phezulu, izovimba okunye ukukhanya futhi inciphise ukusebenza kahle okukhanyayo. Ama-LED anamandla aphezulu aluhlaza angafinyelela ukukhanya okuphuma kahle ngobuchwepheshe be-chip flip kunezindlela zokupakisha ezivamile.
Indlela yamanje yesakhiwo ehlanekezelwe ukuqala ukulungisa ama-chips e-LED anosayizi omkhulu okwesibhakabhaka anama-electrode welding we-eutectic, futhi ngesikhathi esifanayo, ukulungisa i-silicon substrate enkulu kancane kune-chip ye-LED ekhanyayo eluhlaza okwesibhakabhaka, futhi phezu kwayo, yenza igolide conductive ungqimba for eutectic welding kanye lead out ungqimba (ultrasonic igolide wire ball solder joint). Bese, ama-chips e-LED anamandla aphezulu athengiswa kanye nama-silicon substrates kusetshenziswa imishini yokushisela ye-eutectic.
Isici salesi sakhiwo ukuthi ungqimba lwe-epitaxial luthinta ngokuqondile i-silicon substrate, futhi ukumelana nokushisa kwe-silicon substrate kuphansi kakhulu kune-sapphire substrate, ngakho-ke inkinga yokushisa ukushisa ixazululwa kahle. Ngenxa yokuthi i-sapphire substrate ibheke phezulu ngemva kokuguqulwa, ibe indawo ephumayo, isafire ibonakala obala, ngaleyo ndlela ixazulula inkinga yokukhipha ukukhanya. Okungenhla ulwazi olufanele lobuchwepheshe be-LED. Ngikholwa ukuthi ngokuthuthuka kwesayensi nobuchwepheshe,Izibani ze-LEDzizosebenza kahle kakhulu esikhathini esizayo, futhi ukuphila kwazo kwenkonzo kuzothuthukiswa kakhulu, okusilethele ukunethezeka okukhulu.