Itekhnoloji engundoqo yokukhula kweSiC epitaxialimathiriyeli bubuchwephesha bolawulo lwesiphene, ngakumbi kubuchwepheshe bolawulo lwesiphene obuthanda ukusilela kwesixhobo okanye ukuthotywa kokuthembeka. Uphononongo lwendlela ye-substrate defects eyandisa kwi-epitaxial layer ngexesha lenkqubo yokukhula kwe-epitaxial, ukutshintshwa kunye nemithetho yokuguqulwa kweziphene kwi-interface phakathi kwe-substrate kunye ne-epitaxial layer, kunye ne-nucleation mechanism of defects sisiseko sokucacisa ulungelelwaniso phakathi i-substrate defects kunye ne-epitaxial structural defects, engakwazi ukukhokela ngokufanelekileyo ukuhlolwa kwe-substrate kunye ne-epitaxial process optimization.
Iziphene zei-silicon carbide epitaxial layersubukhulu becala zahlulwe zibe ziindidi ezimbini: iziphene zekristale kunye neziphene zemo yomhlaba. Iziphene zeCrystal, ezibandakanya iziphene zamanqaku, i-screw dislocations, i-microtubule defects, i-edge dislocations, njl., ubukhulu becala ivela kwiziphene kwi-substrates ye-SiC kwaye isasazeke kwi-epitaxial layer. Iziphene zemophology yomphezulu zinokujongwa ngokuthe ngqo ngeso lenyama kusetyenziswa imakroskopu kwaye zineempawu eziqhelekileyo zemorphological. Iziphene ze-Scratch morphology ziquka: I-Scratch, i-triangular defect, i-Carrot defect, i-Downfall, kunye ne-Particle, njengoko kuboniswe kwi-Figure 4. Ngexesha lenkqubo ye-epitaxial, amaqhekeza angaphandle, i-substrate defects, umonakalo ongaphezulu, kunye nokuphambuka kwenkqubo ye-epitaxial konke kunokuchaphazela ukuhamba kwamanyathelo wendawo. imo yokukhula, ekhokelela kwiziphene zemo yomhlaba.
Itheyibhile 1. Izizathu zokwenza iziphene eziqhelekileyo ze-matrix kunye neziphene ze-morphology kwi-SiC epitaxial layers
Iziphene
Iziphene zamanqaku zenziwe zizithuba okanye izithuba kwindawo enye yeletiyisi okanye iindawo ezininzi zeeletiyisi, kwaye azinaso sandiso sesithuba. Iziphene zamanqaku zinokuthi zenzeke kuyo yonke inkqubo yemveliso, ngakumbi kufakelo lwe-ion. Nangona kunjalo, kunzima ukuzibona, kwaye ubudlelwane phakathi kokuguqulwa kweziphene kunye nezinye iziphene nazo zinzima kakhulu.
iiMibhobho (MP)
IMibhobho yeMicropipe zizijija ezivulekileyo zokushenxiswa ezisasaza ecaleni kwe-axis yokukhula, nge-Burgers vector <0001>. Ububanzi be-microtubes busuka kwiqhezu le-micron ukuya kumashumi ee-microns. Ii-Microtubes zibonisa iimpawu ezinkulu ezinjengomngxuma kumphezulu wee-wafers ze-SiC. Ngokuqhelekileyo, ubuninzi bee-microtubes malunga ne-0.1 ~ 1cm-2 kwaye iyaqhubeka iyancipha ekubekweni esweni komgangatho wemveliso ye-wafer.
I-Screw dislocations (TSD) kunye ne-edge dislocations (TED)
Ukukhutshwa kwi-SiC ngowona mthombo uphambili wokuthotywa kwesixhobo kunye nokungaphumeleli. Zombini i-screw dislocations (TSD) kunye ne-edge dislocations (TED) zihamba kunye ne-axis yokukhula, kunye ne-Burgers vectors ye- <0001> kunye ne-1/3<11–20>, ngokulandelanayo.
Zombini i-screw dislocations (TSD) kunye ne-edge dislocations (TED) inokwandisa ukusuka kwi-substrate ukuya kwi-wafer surface kwaye izise iimpawu zomphezulu ezincinci ezifana nomngxuma (Figure 4b). Ngokuqhelekileyo, ubuninzi be-edge dislocations malunga namaxesha ali-10 e-screw dislocations. Ukwandiswa kwe-screw dislocations, oko kukuthi, ukusuka kwi-substrate ukuya kwi-epilayer, inokuguqula ibe kwezinye iziphene kwaye isasaze kunye ne-axis yokukhula. NgexeshaSiC epitaxialukukhula, i-screw dislocations iguqulwa ibe yimpazamo yokupakisha (SF) okanye i-carrot defects, ngelixa i-edge dislocations kwi-epilayers iboniswa ukuba iguqulwe kwi-basal plane dislocations (BPDs) ezuzwe kwi-substrate ngexesha lokukhula kwe-epitaxial.
Ukususwa kwenqwelomoya okusisiseko (BPD)
Ifumaneka kwi-SiC basal plane, kunye ne-Burgers vector ye-1/3 <11-20>. Ii-BPD azifane zivele kumphezulu wee-wafers ze-SiC. Ngokuqhelekileyo zigxininiswe kwi-substrate ngobuninzi be-1500 cm-2, ngelixa ubuninzi babo kwi-epilayer bumalunga ne-10 cm-2 kuphela. Ukufunyanwa kwe-BPDs usebenzisa i-photoluminescence (PL) ibonisa iimpawu zomgca, njengoko kuboniswe kwi-Figure 4c. NgexeshaSiC epitaxialukukhula, i-BPDs eyandisiweyo inokuguqulwa ibe yimpazamo yokupakisha (SF) okanye i-edge dislocations (TED).
Ukupakisha iimpazamo (SFs)
Iziphene kulandelelwano lwe-stacking ye-SiC basal plane. Iziphoso zokupakisha zingabonakala kwi-epitaxial layer ngokuzuza ilifa le-SFs kwi-substrate, okanye inxulumene nokwandiswa kunye nokuguqulwa kwe-basal plane dislocations (BPDs) kunye ne-threading screw dislocations (TSDs). Ngokuqhelekileyo, ubuninzi be-SFs bungaphantsi kwe-1 cm-2, kwaye babonisa isici se-triangular xa sifunyenwe usebenzisa i-PL, njengoko kuboniswe kuMfanekiso 4e. Nangona kunjalo, iintlobo ezahlukeneyo zeempazamo zokupakisha zinokuqulunqwa kwi-SiC, njengohlobo lwe-Shockley kunye nohlobo lukaFrank, kuba nokuba umlinganiselo omncinci wokuphazamiseka kwamandla phakathi kweenqwelomoya kunokukhokelela ekungalandeleni okubonakalayo kulandelelwano lokupakisha.
Ukuwa
Isiphene sokuwa ikakhulu sisuka kwi-particle drop on the top and side side wall of the reaction chamber ngexesha lenkqubo yokukhula, enokuthi iphuculwe ngokulungiselela inkqubo yokugcinwa kwamaxesha athile kwe-reaction chamber graphite consumables.
Isiphene esingunxantathu
Kukubandakanywa kwe-polytype ye-3C-SiC efikelela kumphezulu we-SiC epilayer ecaleni kwendlela yendiza ye-basal, njengoko kuboniswe kuMfanekiso 4g. Inokuveliswa ngamaqhekeza awela phezu komhlaba we-SiC epilayer ngexesha lokukhula kwe-epitaxial. Iinqununu zifakwe kwi-epilayer kwaye ziphazamise inkqubo yokukhula, okubangelwa i-3C-SiC ye-polytype inclusions, ebonisa iimpawu ezibukhali ze-triangular surface kunye neengqungquthela ezibekwe kwii-vertices zengingqi ye-triangular. Izifundo ezininzi ziye zaxela imvelaphi yokubandakanywa kwe-polytype kwimikrwelo yomhlaba, ii-micropipes, kunye neeparamitha ezingafanelekanga zenkqubo yokukhula.
Isiphene sekherothi
I-carrot defect yi-stacking fault complex eneziphelo ezimbini ezifumaneka kwi-TSD kunye ne-SF basal crystal planes, epheliswe yi-frank-type dislocation, kunye nobukhulu be-carrot defect ihambelana ne-prismatic stacking fault. Ukudibanisa kwezi mpawu zenza i-morphology yomhlaba ye-carrot defect, ebonakala ngathi i-carrot shape kunye nobuninzi obungaphantsi kwe-1 cm-2, njengoko kuboniswe kwi-Figure 4f. Iziphene zekherothi zenziwe ngokulula kwimikrwelo yokupolisha, ii-TSD, okanye iziphene ze-substrate.
Imikrwelo
Imikrwelo ngumonakalo owenziwe ngoomatshini kumphezulu wee-wafers ze-SiC ezenziwe ngexesha lenkqubo yokuvelisa, njengoko kubonisiwe kwi-Figure 4h. Ukukrazula kwi-substrate ye-SiC kunokuphazamisa ukukhula kwe-epilayer, ukuvelisa umgca we-high-density dislocations ngaphakathi kwe-epilayer, okanye i-scratches ingaba sisiseko sokwakheka kwe-carrot defects. Ke ngoko, kubalulekile ukupolisha ngokufanelekileyo ii-wafers ze-SiC kuba ezi zikrwelo zinokuba nempembelelo enkulu ekusebenzeni kwesixhobo xa zivela kwindawo esebenzayo yesixhobo.
Ezinye iziphene zokwakheka komhlaba
I-Step bunching yintsilelo yomhlaba eyenziwe ngexesha lenkqubo yokukhula kwe-SiC epitaxial, evelisa oonxantathu obunzima okanye iimpawu ze-trapezoidal kumphezulu we-SiC epilayer. Zininzi ezinye iziphene ezingaphezulu, njengemingxuma engaphezulu, amaqhuma kunye namabala. Ezi ziphene zidla ngokubangelwa yinkqubo yokukhula engafanelekanga kunye nokususwa okungaphelelanga komonakalo wokupolisha, ochaphazela kakubi ukusebenza kwesixhobo.
Ixesha lokuposa: Jun-05-2024