Uburyo bwo gukora ifu imwe ya SiC ifite isuku nyinshi

Mu buryo bwo gukuraho karuboni imwe ya silikoni, gutwara umwuka ukomoka ku mwuka ni bwo buryo bugezweho bwo guteza imbere inganda. Ku buryo bwo gukuraho karuboni imwe,ifu ya karubide ya silikonibigira ingaruka zikomeye ku mikurire. Ibipimo byose byaifu ya karubide ya silikonibigira ingaruka zitaziguye ku bwiza bw'ikura rya kristu imwe n'imiterere y'amashanyarazi. Mu nganda zikoreshwa ubu, ikoreshwa cyaneifu ya karubide ya silikoniUburyo bwo gukora imvange ni bwo buryo bwo gukora imvange bwikora mu bushyuhe bwinshi.
Uburyo bwo kwiyamamaza mu bushyuhe bwinshi bukoresha ubushyuhe bwinshi kugira ngo buhe ibinyabutabire ubushyuhe bw'ibanze bwo gutangiza ibikorwa bya shimi, hanyuma bugakoresha ubushyuhe bwabwo bwite bwo kwiyamamaza kugira ngo ibintu bitarakorwa bikomeze kurangiza ibikorwa bya shimi. Ariko, kubera ko ibikorwa bya shimi bya Si na C bisohora ubushyuhe buke, hagomba kongerwamo ibindi bintu kugira ngo bikomeze gukora. Kubwibyo, intiti nyinshi zatanze igitekerezo cyuburyo bwiza bwo kwiyamamaza muri ubu buryo, hashyirwaho igikoresho kibikora. Uburyo bwo kwiyamamaza bworoshye gushyira mu bikorwa, kandi ibipimo bitandukanye byo kwiyamamaza biroroshye kugenzura neza. Kwiyamamaza mu buryo bunini bihura n'ibikenewe mu nganda.

Mu 1999, Bridgeport yakoresheje uburyo bwo kwihuza bukoresha ubushyuhe bwinshi kugira ngo ikoreshweIfu ya SiC, ariko yakoresheje ethoxysilane na phenol resin nk'ibikoresho fatizo, byari bihenze cyane. Gao Pan n'abandi bakoresheje ifu ya Si na C powder ifite isuku nyinshi nk'ibikoresho fatizo mu gukoraIfu ya SiCbitewe n'ubushyuhe bwinshi mu kirere cya argon. Ning Lina yateguye uduce dutoIfu ya SiCbinyuze mu guhuza ibice bibiri.

Ifuru ishyushya ikoresheje frequency iri hagati yakozwe n'ikigo cya kabiri cy'ubushakashatsi cy'Ubushinwa Electronics Technology Group Corporation ivanga ifu ya silikoni n'ifu ya karuboni ku gipimo runaka cya stoichiometric hanyuma ikabishyira mu cyuma gishyushya girafu.icyuma gikozwe muri grafitiishyirwa mu itanura rishyushya ry’ingufu riciriritse kugira ngo rishyushye, kandi impinduka z’ubushyuhe zikoreshwa mu guhuza no guhindura imiterere y’ingufu z’ubushyuhe bwo hasi n’ingufu z’ubushyuhe bwo hejuru. Kubera ko ubushyuhe bw’imikorere ya β-SiC mu gice cy’ubushyuhe bwo hasi buri hasi ugereranije n’ubushyuhe bwa Si, guhuza β-SiC munsi y’ubushyuhe bwinshi bishobora gutuma yikwirakwiza. Uburyo bwo kwinjiza gazi ya argon, hydrogen na HCl mu guhuza α-SiC burinda kubora kwaIfu ya SiCmu cyiciro cy'ubushyuhe bwinshi, kandi bishobora kugabanya neza ingano ya azote mu ifu ya α-SiC.

Shandong Tianyue yakoze itanura rikoreshwa mu gutunganya ibintu, ikoresheje gaze ya silane nk'ibikoresho bya silikoni n'ifu ya karuboni nk'ibikoresho bya karuboni. Ingano ya gaze y'ibikoresho bya karuboni yashyizweho yahinduwe hakoreshejwe uburyo bwo gutunganya ibintu mu ntambwe ebyiri, kandi ingano ya nyuma ya karuboni ya silikoni yari hagati ya 50 na 5000 um.

 

1 Ibintu bigenzura imikorere y'ifu

 

1.1 Ingaruka z'ingano y'uduce tw'ifu ku mikurire ya kristu

Ingano y'uduce twa silicon carbide ifu ifite ingaruka zikomeye ku mikurire ya kristu imwe ikurikiraho. Imikurire ya kristu imwe ya SiC hakoreshejwe uburyo bwa PVT igerwaho ahanini binyuze mu guhindura igipimo cya molar cya silicon na karubone mu gice cya gaze, kandi igipimo cya molar cya silicon na karubone mu gice cya gaze gifitanye isano n'ingano y'uduce twa kristu carbide ifu. Igitutu cyose n'igipimo cya silicon-karubone by'uburyo bwo gukura byiyongera uko ingano y'uduce igabanuka. Iyo ingano y'uduce igabanutse kuva kuri mm 2-3 kugera kuri mm 0.06, igipimo cya silicon-karubone kiriyongera kuva kuri 1.3 kugeza kuri 4.0. Iyo uduce duto ku rugero runaka, igitutu cya Si kiriyongera, kandi urwego rwa filime ya Si rukorwa ku buso bwa kristu ikura, bigatera gukura kwa kristu ikura, bigatera gukura kwa kristu ikura, inenge z'ingingo n'inenge z'umurongo muri kristu. Kubwibyo, ingano y'uduce twa kristu ikura cyane igomba kugenzurwa neza.

Byongeye kandi, iyo ingano y'uduce twa SiC ari duto, ifu ibora vuba, bigatuma kristu imwe ya SiC ikura cyane. Ku ruhande rumwe, mu bushyuhe bwinshi bw'ikura rya kristu imwe ya SiC, inzira ebyiri zo gukora no gusenya zikorwa icyarimwe. Ifu ya silika ya karuboni izabora igakora karuboni mu gice cya gaze n'igice gikomeye nka Si, Si2C, SiC2, bigatuma ifu ya polycrystalline ihinduka cyane kandi hagashyirwaho karuboni muri kristu; ku rundi ruhande, iyo igipimo cyo gusenya ifu cyihuta cyane, imiterere ya kristu ya SiC imwe yakuze irahinduka, bigatuma bigorana kugenzura ubwiza bwa kristu imwe ya SiC yakuze.

 

1.2 Ingaruka z'ibumba rya kristu ku mikurire ya kristu

Gukura kwa kristalo imwe ya SiC hakoreshejwe uburyo bwa PVT ni inzira yo kongeramo kristalo ku bushyuhe bwinshi. Ubwoko bwa kristalo bw'ibikoresho fatizo bya SiC bufite ingaruka zikomeye ku mikurire ya kristalo. Mu nzira yo gukora ifu, hakorwa ahanini icyiciro cyo gukora ifu y'ubushyuhe buke (β-SiC) gifite imiterere ya cube y'akaremangingo k'igice n'icyiciro cyo gukora ifu y'ubushyuhe bwinshi (α-SiC) gifite imiterere ya hexagonal y'akaremangingo k'igice. Hariho imiterere myinshi ya kristalo ya silicon carbide n'urwego ruto rwo kugenzura ubushyuhe. Urugero, 3C-SiC izahinduka polymorph ya silicon carbide ya hexagonal, ni ukuvuga 4H/6H-SiC, ku bushyuhe buri hejuru ya 1900°C.

Mu gihe cy'ikura rya kristu imwe, iyo ifu ya β-SiC ikoreshwa mu gukura kristu, igipimo cya kristu ya silikoni-karuboni kiba kinini kurusha 5.5, mu gihe iyo ifu ya α-SiC ikoreshwa mu gukura kristu, igipimo cya kristu ya silikoni-karuboni ni 1.2. Iyo ubushyuhe buzamutse, habaho ihinduka ry'icyiciro mu cyuma gishyushya. Muri iki gihe, igipimo cya kristu mu gice cya kristu kiba kinini, ibyo bikaba bidafasha gukura kwa kristu. Byongeye kandi, indi myanda ya kristu, harimo na karuboni, silikoni, na dioxyde ya silikoni, iboneka byoroshye mu gihe cy'ihinduka rya kristu. Kuba hari iyi myanda bituma kristu ibyara utubumbe duto n'imyanda. Kubwibyo, imiterere ya kristu ya silikoni igomba kugenzurwa neza.

 

1.3 Ingaruka z'imyanda y'ifu ku mikurire ya kristu

Ingano y'umwanda iri mu ifu ya SiC igira ingaruka ku miterere y'ingirabuzimafatizo mu gihe cy'ikura rya kristu. Uko ingano y'umwanda iba nyinshi, ni ko kristu idashobora kwiyahura mu buryo butunguranye. Kuri SiC, imyanda y'ingenzi mu byuma irimo B, Al, V, na Ni, ishobora gushyirwa mu bikoresho byo gutunganya mu gihe cyo gutunganya ifu ya silicon na karuboni. Muri byo, B na Al ni imyanda y'ingenzi ifata ingufu nke muri SiC, bigatuma SiC igabanuka. Indi myanda y'icyuma izamura ingufu nyinshi, bigatuma imiterere y'amashanyarazi ya kristu imwe ya SiC ihindagurika ku bushyuhe bwinshi, kandi ikagira ingaruka zikomeye ku miterere y'amashanyarazi ya kristu imwe ifite ubuziranenge buhanitse, cyane cyane iyo irwanya. Kubwibyo, ifu ya kristu ya karuboni ifite ubuziranenge buhanitse igomba gukorwa uko bishoboka kose.

 

1.4 Ingaruka z'umubumbe wa azote mu ifu ku mikurire ya kristu

Urugero rw'ingano ya azote rugena ubushobozi bwo guhangana n'ingufu za substrate imwe ya kristu. Inganda zikomeye zigomba guhindura ingano ya azote mu bikoresho bya sintetike hakurikijwe uburyo kristu yakuze ikura mu gihe cyo gukora ifu. Substrate ya silicon carbide imwe ya kristu ifite ubuziranenge buhanitse ni ibikoresho byiza cyane ku bikoresho bya elegitoroniki bya gisirikare. Kugira ngo hakorwe substrate ya kristu imwe ifite ubuziranenge buhanitse ifite ubuziranenge buhanitse kandi ifite imiterere myiza y'amashanyarazi, ingano ya azote y'ingenzi mu butaka igomba kugenzurwa ku rwego rwo hasi. Substrate ya kristu imwe itwara amashanyarazi isaba ko azote igenzurwa ku rugero rwo hejuru.

 

2 Ikoranabuhanga ry'ingenzi ryo kugenzura ifu

Bitewe n’uburyo butandukanye bwo gukoresha substrates za silicon carbide, ikoranabuhanga ryo gukora ifu yo gukura rifite imikorere itandukanye. Ku ifu yo gukura ya kristu imwe yo mu bwoko bwa N, hakenewe ubuziranenge bwinshi n’icyiciro kimwe; mu gihe ku ifu yo gukura ya kristu imwe yo mu bwoko bwa semi-infurized, hakenewe kugenzura cyane ingano ya azote.

 

2.1 Kugenzura ingano y'uduce tw'ifu

2.1.1 Ubushyuhe bwo gukora isesengura

Mu gukomeza kugira izindi nzira zihinduka, ifu ya SiC ikorwa ku bushyuhe bwa synthesis bwa 1900 ℃, 2000 ℃, 2100 ℃, na 2200 ℃ yarapimwe kandi irasesengurwa. Nk'uko bigaragara ku Ishusho ya 1, bigaragara ko ingano y'uduce ari 250 ~ 600 μm kuri 1900 ℃, kandi ingano y'uduce yiyongera ikagera kuri 600 ~ 850 μm kuri 2000 ℃, kandi ingano y'uduce ihinduka cyane. Iyo ubushyuhe bukomeje kuzamuka bukagera kuri 2100 ℃, ingano y'uduce twa SiC ni 850 ~ 2360 μm, kandi ukwiyongera gukunda kuba guto. Ingano y'uduce twa SiC kuri 2200 ℃ irahamye kuri 2360 μm. Kwiyongera k'ubushyuhe bwa synthesis kuva kuri 1900 ℃ bigira ingaruka nziza ku bunini bw'uduce twa SiC. Iyo ubushyuhe bwa synthesis bukomeje kwiyongera kuva kuri 2100 ℃, ingano y'uduce ntiyongera guhinduka cyane. Bityo rero, iyo ubushyuhe bwa synthesis bushyizwe kuri 2100 ℃, ingano nini y'uduce ishobora gukorwa ku ngufu nkeya.

 

2.1.2 Igihe cyo gukora isesengura

Izindi ngingo zijyanye n'imikorere ntizihinduka, kandi igihe cyo gukora isesengura kigomba kuba amasaha 4, amasaha 8, n'amasaha 12. Isesengura ryakozwe ry'ifu ya SiC rigaragazwa ku Ishusho ya 2. Byagaragaye ko igihe cyo gukora isesengura bigira ingaruka zikomeye ku bunini bw'uduce twa SiC. Iyo igihe cyo gukora isesengura ari amasaha 4, ingano y'uduce ikwirakwira cyane kuri 200 μm; iyo igihe cyo gukora isesengura ari amasaha 8, ingano y'uduce twa sintetike iriyongera cyane, ahanini ikwirakwira kuri 1 000 μm; uko igihe cyo gukora isesengura gikomeza kwiyongera, ingano y'uduce iriyongera cyane, ahanini ikwirakwira kuri 2 000 μm.

 

2.1.3 Ingaruka z'ingano y'uduce tw'ibikoresho fatizo

Uko uruhererekane rw'ibikoresho bya silikoni byo mu rugo rugenda rurushaho kuba rwiza, ni nako isuku y'ibikoresho bya silikoni nayo irushaho kuba nziza. Kuri ubu, ibikoresho bya silikoni bikoreshwa mu gukora ibintu bigabanyijemo silikoni y'ibinyabutabire na silikoni y'ifu, nk'uko bigaragara ku Ishusho ya 3.

Ibikoresho bitandukanye bya silikoni byakoreshejwe mu gukora igerageza rya silikoni karubide. Igereranya ry'ibicuruzwa bya silikoni rigaragazwa ku Ishusho ya 4. Isesengura ryerekana ko iyo ukoresheje ibikoresho bya silikoni bya block, hari ibintu byinshi bya Si mu bicuruzwa. Nyuma y'uko block ya silikoni isheshwe ku nshuro ya kabiri, ikintu cya Si mu bicuruzwa bya silikoni kiragabanuka cyane, ariko kiracyariho. Amaherezo, ifu ya silikoni ikoreshwa mu gukora, kandi SiC ni yo yonyine iba iri mu bicuruzwa. Ibi biterwa nuko mu gukora, silikoni nini cyane igomba kubanza gukora reaction ya synthesis surface, maze silikoni karubide ikorwa ku buso, ibi bikabuza ifu ya Si imbere gukomeza kwivanga na C powder. Kubwibyo, niba block silicon ikoreshejwe nk'ibikoresho bya fatizo, igomba gushwanyaguzwa hanyuma igashyirwa mu buryo bwa second synthesis kugira ngo haboneke ifu ya silikoni karubide yo gukura.

 

2.2 Kugenzura ifu ya kristu

 

2.2.1 Ingaruka z'ubushyuhe bw'imikorere

Mu gukomeza kugira izindi gahunda zidahinduka, ubushyuhe bwa synthesis ni 1500℃, 1700℃, 1900℃, na 2100℃, kandi ifu ya SiC yakozwe irapimwa kandi igasesengurwa. Nk'uko bigaragara ku Ishusho ya 5, β-SiC ni umuhondo w'isi, naho α-SiC ikaba yoroheje mu ibara. Mu kwitegereza ibara n'imiterere y'ifu yakozwe, bishobora kugaragara ko umusaruro wakozwe ari β-SiC ku bushyuhe bwa 1500℃ na 1700℃. Kuri 1900℃, ibara riba ryoroheje, kandi uduce duto tugaragara, bigaragaza ko nyuma y'ubushyuhe buzamutse bukagera kuri 1900℃, habaho ihinduka ry'icyiciro, maze igice cya β-SiC kigahinduka α-SiC; iyo ubushyuhe bukomeje kuzamuka bukagera kuri 2100℃, usanga uduce twakozwe dutanga urumuri, kandi α-SiC ikaba yarahinduwe.

 

2.2.2 Ingaruka z'igihe cyo gukora isesengura

Izindi ngingo zijyanye n'imikorere ntizihinduka, kandi igihe cyo gukora isesengura kigomba kuba amasaha 4, amasaha 8, na 12. Ifu ya SiC ikorwa irapimwa kandi igasesengurwa hakoreshejwe diffractometer (XRD). Ibisubizo bigaragara ku Ishusho ya 6. Igihe cyo gukora isesengura gifite ingaruka runaka ku bicuruzwa byakozwe na SiC powder. Iyo igihe cyo gukora isesengura ari amasaha 4 na 8, ibicuruzwa byakozwe ahanini ni 6H-SiC; iyo igihe cyo gukora isesengura ari amasaha 12, 15R-SiC igaragara mu bicuruzwa.

 

2.2.3 Ingaruka z'igipimo cy'ibikoresho fatizo

Izindi nzira ntizihinduka, ingano y'ibintu bya silikoni-karuboni irasesengurwa, kandi ibipimo ni 1.00, 1.05, 1.10 na 1.15 ku buryo bukurikiranye ku igerageza rya synthesis. Ibisubizo bigaragara ku Ishusho ya 7.

Ukurikije XRD spectrum, bigaragara ko iyo igipimo cya silikoni-karuboni kirenze 1.05, Si irenze igaragara mu gicuruzwa, naho iyo igipimo cya silikoni-karuboni kiri munsi ya 1.05, C irenze igaragara. Iyo igipimo cya silikoni-karuboni kiri 1.05, karuboni yigenga mu gicuruzwa cya sintetike irakurwaho, kandi nta silikoni yigenga igaragara. Kubwibyo, igipimo cy'ingano ya silikoni-karuboni kigomba kuba 1.05 kugira ngo hakorwe SiC ifite isuku nyinshi.

 

2.3 Kugenzura ingano nke ya azote mu ifu

2.3.1 Ibikoresho fatizo by'ubukorikori

Ibikoresho fatizo byakoreshejwe muri ubu bushakashatsi ni ifu ya karuboni isukuye cyane n'ifu ya silikoni isukuye cyane ifite umurambararo wa 20 μm. Bitewe n'ubunini bwazo buto n'ubuso bunini bwihariye, biroroshye kwinjiza N2 mu kirere. Mu gukora ifu, izanwa mu ishusho ya kristu y'ifu. Kugira ngo kristu zo mu bwoko bwa N zikure, gukwirakwiza N2 mu ifu bidahuje bituma kristu idakomera ndetse binahinduka mu ishusho ya kristu. Ingano ya azote mu ifu yakozwe nyuma y'uko hidrojeni ishyizwemo ni nto cyane. Ibi biterwa nuko ingano ya molecule za hydrogen ari nto. Iyo N2 yinjijwe mu ifu ya karuboni n'ifu ya silikoni ishyushye kandi ikava ku buso, H2 ikwirakwira neza mu cyuho kiri hagati y'ifu hamwe n'ingano yayo nto, igasimbuza aho N2 iri, maze N2 igasohoka mu cyuma mu gihe cyo gusohora umwuka, ikagera ku ntego yo gukuraho azote.

 

2.3.2 Uburyo bwo gukora isesengura

Mu gihe cyo gukora ifu ya karuboni, kubera ko uburebure bw'atome za karuboni na atome za azote busa, azote izasimbura icyuho cya karuboni muri karuboni ya silicon, bityo yongera ingano ya azote. Ubu buryo bwo kugerageza bukoresha uburyo bwo kwinjiza H2, maze H2 igakorana n'ibintu bya karuboni na silicon mu gice cyo gukora kugira ngo ikore imyuka ya C2H2, C2H, na SiH. Ingano y'ibintu bya karuboni iriyongera binyuze mu kohereza gaze, bityo ikagabanya icyuho cya karuboni. Intego yo gukuraho azote iragerwaho.

 

2.3.3 Kugenzura ingano ya azote inyuma y'ibikorwa

Ibikoresho bya grafiti bifite porosity nini bishobora gukoreshwa nk'inyongera ku masoko ya C kugira ngo byinjize umwuka wa Si mu bice bya gaze, bigabanye Si mu bice bya gaze, bityo byongera C/Si. Muri icyo gihe, ibikoresho bya grafiti bishobora kandi gukorana n'ikirere cya Si kugira ngo bikore Si2C, SiC2 na SiC, bingana n'ikirere cya Si kizana isoko ya C iva kuri grafiti crucible mu kirere gikura, byongera igipimo cya C, ndetse binakongera igipimo cya karuboni na silicon. Kubwibyo, igipimo cya karuboni na silicon gishobora kongerwa hakoreshejwe ibikoresho bya grafiti bifite porosity nini, bikagabanya umwanya wa karuboni, kandi bikagera ku ntego yo gukuraho azote.

 

3 Isesengura n'igishushanyo mbonera cy'uburyo bwo gukora ifu imwe ya kristu

 

3.1 Ihame n'imiterere y'inzira yo guhuza

Binyuze mu bushakashatsi burambuye bwavuzwe haruguru ku kugenzura ingano y'uduce, imiterere ya kristu n'ingano ya azote mu ikorwa ry'ifu, haratangwa uburyo bwo gukora. Ifu ya C ifite isuku nyinshi n'ifu ya Si biratoranywa, kandi bivanze neza bigashyirwa mu cyuma gikoresha icyuma cya graphite hakurikijwe igipimo cya silicon-carbon cya 1.05. Intambwe z'ibikorwa zigabanyijemo ibice bine:
1) Uburyo bwo gukuraho nitrogen mu bushyuhe buke, gusohora 5×10-4 Pa, hanyuma ugashyiramo hydrogen, bigatuma igitutu cy'icyumba kigera kuri 80 kPa, bikamara iminota 15, kandi bigasubirwamo inshuro enye. Ubu buryo bushobora gukuraho ibintu bya azote ku buso bw'ifu ya karuboni na silicon powder.
2) Uburyo bwo gukuraho nitrogen mu bushyuhe bwinshi, gusohora 5×10-4 Pa, hanyuma gushyushya kugeza kuri 950 ℃, hanyuma ugashyiramo hydrogen, bigatuma umuvuduko w'icyumba ugera kuri 80 kPa, bikagumana iminota 15, kandi bigasubirwamo inshuro enye. Ubu buryo bushobora gukuraho ibintu bya nitrogen ku buso bw'ifu ya karuboni na silicon powder, kandi bugashyira azote mu murima w'ubushyuhe.
3) Gutunganya ubushyuhe buke, shyiramo 5×10-4 Pa, hanyuma ushyushye 1350℃, bika mu masaha 12, hanyuma ushyiremo hydrogen kugira ngo igitutu cy'icyumba kibe 80 kPa, bika mu gihe cy'isaha 1. Ubu buryo bushobora gukuraho azote yahindutse mu gihe cyo gukora ingano.
4) Gutunganya inzira y'ubushyuhe bwinshi, kuzuza igipimo runaka cy'amazi ya gazi ya hydrogen na argon ivanze, bituma umuvuduko w'icyumba ugera kuri kPa 80, kuzamura ubushyuhe bukagera kuri 2100℃, bikabikwa mu gihe cy'amasaha 10. Iyi nzira irangiza ihinduka rya silicon carbide iva kuri β-SiC ikajya kuri α-SiC kandi ikarangiza gukura kw'uduce twa kristu.
Amaherezo, tegereza ubushyuhe bw'icyumba bukonje kugeza ku bushyuhe bw'icyumba, wuzuze kugeza ku gitutu cy'ikirere, hanyuma ukuremo ifu.

 

3.2 Uburyo bwo gutunganya ifu nyuma yo kuyitunganya

Nyuma y’uko ifu ikozwe muri ubu buryo bwavuzwe haruguru, igomba gutunganywa nyuma yo kuyitunganya kugira ngo ikureho imyanda ya karuboni, silikoni n’indi metali kandi ikoreshwe ingano y’uduce. Ubwa mbere, ifu yakozwe ishyirwa mu cyuma gisya kugira ngo icurwe, hanyuma ifu ya silikoni yaciwe ishyirwa mu itanura rishyushye kugeza kuri 450°C na ogisijeni. Karuboni yigenga iri mu ifu ishyirwamo ogisijeni n’ubushyuhe kugira ngo ikore gaze ya karuboni isohoka mu cyumba, bityo karuboni yigenga ikavamo. Nyuma yaho, hategurwa amazi yo gusukura aside agashyirwa mu mashini isukura uduce twa silikoni kugira ngo isukurwe kugira ngo ikureho imyanda ya karuboni, silikoni n’ibindi bisigaye by’icyuma byakozwe mu gihe cyo kuyitunganya. Nyuma y’ibyo, aside isigaye yogezwa mu mazi meza hanyuma ikamanurwa. Ifu yumye ishyirwa mu cyuma gipima ingano y’uduce kugira ngo hatoranywe ingano ya kristu.