Ndezvipi zvikanganiso zvesilicon carbide epitaxial layer?

Tekinoroji huru yekukura kweSiC epitaxialZvinhu zvekutanga inyanzvi yekudzora zvikanganiso, kunyanya tekinoroji yekudzora zvikanganiso iyo inogona kukanganisa mudziyo kana kuora kwekuvimbika. Kudzidza mashandiro ezvikanganiso zve substrate zvichienda mu epitaxial layer panguva yekukura kwe epitaxial, mitemo yekufambisa nekushandura zvikanganiso pakubatana pakati pe substrate ne epitaxial layer, uye nzira ye nucleation yezvikanganiso ndiyo hwaro hwekujekesa hukama huripo pakati pezvikanganiso zve substrate nezvikanganiso zve epitaxial structure, izvo zvinogona kutungamira zvinobudirira kuongorora substrate uye kugadzirisa maitiro e epitaxial.

Zvikanganiso zvesilicon carbide epitaxial layersZvikurukuru zvakakamurwa muzvikamu zviviri: zvikanganiso zvekristaro uye zvikanganiso zvechimiro chepamusoro. Zvikanganiso zvekristaro, zvinosanganisira zvikanganiso zvepoint, dislocations dzescrew, microtubule defects, edge dislocations, nezvimwewo, zvinonyanya kubva pazvikanganiso zviri paSiC substrates uye zvinopararira mu epitaxial layer. Zvikanganiso zvechimiro chepamusoro zvinogona kuonekwa zvakananga neziso risina chinhu uchishandisa maikorosikopu uye zvine hunhu hwakajairika hwechimiro. Zvikanganiso zvechimiro chepamusoro zvinosanganisira: Scratch, Triangular defect, Carrot defect, Downfall, uye Particle, sezvakaratidzwa muMufananidzo 4. Munguva ye epitaxial process, zvidimbu zvekunze, zvikanganiso zvesubstrate, kukuvara kwenzvimbo, uye epitaxial process deviations zvese zvinogona kukanganisa local step flow growth mode, zvichikonzera zvikanganiso zvechimiro chepamusoro.

Tafura 1. Zvinokonzera kuumbwa kwezvikanganiso zvematrix zvakajairika uye zvikanganiso zvechimiro chepamusoro muSiC epitaxial layers

 

Zvikanganiso zvemapoinzi

Kukanganisika kwemapoinzi kunoumbwa nekusava nechinhu kana mipata panzvimbo imwe chete kana nzvimbo dzakawanda dzemapoinzi, uye hazvina nzvimbo yakakura. Kukanganisika kwemapoinzi kunogona kuitika mune yega yega nzira yekugadzira, kunyanya mukuisa maion. Zvisinei, zvakaoma kuona, uye hukama huripo pakati pekushandurwa kwemapoinzi nezvimwe zvikanganiso hwakaomawo.

 

Mapombi madiki (MP)

Ma micropipes ihollow screw dislocations inopararira pamwe chete ne growth axis, ine Burgers vector <0001>. Dhayamita yema microtubes inotangira pachikamu che micron kusvika kumakumi ema microns. Ma microtubes anoratidza zvinhu zvakakura zvakaita segomba pamusoro pe SiC wafers. Kazhinji, density yema microtubes inenge iri 0.1 ~ 1cm-2 uye inoramba ichiderera mukutarisa kunaka kwekugadzirwa kwe wafer yekutengeserana.

 

Kubviswa kwescrew (TSD) uye kubviswa kwe edge (TED)

Kukanganisika kweSiC ndiko kunonyanya kukonzera kuora kwemidziyo uye kutadza kushanda kwayo. Kukanganisika kwescrew (TSD) ne edge dislocations (TED) zvese zvinofamba negrowth axis, neBurgers vectors dze<0001> ne1/3<11–20>, zvichiteerana.

Kubviswa kwescrew (TSD) uye kubviswa kwe edge dislocations (TED) zvinogona kubva pasi pe substrate kuenda pamusoro pe wafer uye zvinounza zvinhu zvidiki zvakaita se pit surface (Mufananidzo 4b). Kazhinji, huwandu hwe edge dislocations hunopetwa kagumi kupfuura kubviswa kwescrew. Kubviswa kwescrew kwakawedzerwa, kureva kuti, kubva pasi pe substrate kuenda ku epilayer, kunogonawo kushanduka kuita zvimwe zvikanganiso uye kupararira pamwe chete ne growth axis. Munguva yekushandiswa kwe edge dislocations, screw dislocations dzinoshandiswa pa epilayer dzinoshandiswa pa epilayer.SiC epitaxialkukura, kupatsanurwa kwe screw kunoshandurwa kuita stacking faults (SF) kana carrot defects, nepo kupatsanurwa kwe edge mu epilayers kunoratidzwa kuti kunoshandurwa kubva ku basal plane dislocations (BPDs) dzakagarwa nhaka kubva ku substrate panguva yekukura kwe epitaxial.

 

Kubviswa kwendege kwakakosha (BPD)

Iri panzvimbo yeSiC basal plane, ine Burgers vector ye1/3 <11–20>. MaBPD haawanzoonekwa pamusoro peSiC wafers. Anowanzo kuve akanyanya kuzara pamusoro pe substrate ine density ye1500 cm-2, nepo density yavo mu epilayer iri 10 cm-2 chete. Kuonekwa kweBPDs uchishandisa photoluminescence (PL) kunoratidza zvinhu zvakatsetseka, sezvakaratidzwa muMufananidzo 4c. Munguva yeSiC epitaxialkukura, maBPD akawedzerwa anogona kushandurwa kuita ma stacking faults (SF) kana edge dislocations (TED).

 

Zvikanganiso zvekuunganidza zvinhu (SFs)

Zvikanganiso mumutsara wekuisa zvinhu muSiC basal plane. Zvikanganiso zvekuisa zvinhu muzvikamu zvinogona kuoneka muchikamu cheepitaxial nekugara nhaka maSF muchikamu chepasi, kana kuti zvine chekuita nekuwedzerwa nekushandurwa kwe basal plane dislocations (BPDs) uye threading screw dislocations (TSDs). Kazhinji, huwandu hwemaSFs huri pasi pe1 cm-2, uye hunoratidza chimiro chetriangular kana hukaonekwa uchishandisa PL, sezvakaratidzwa muMufananidzo 4e. Zvisinei, mhando dzakasiyana dzezvikanganiso zvekuisa zvinhu muzvikamu dzinogona kuumbwa muSiC, dzakadai seShockley type neFrank type, nekuti kunyangwe kusagadzikana kwesimba rekuisa zvinhu muzvikamu kunogona kukonzera kusagadzikana kukuru mumutsara wekuisa zvinhu muzvikamu.

 

Kudonha

Kukanganisika kwekudonha kunonyanya kubva pakudonha kwezvikamu pamadziro epamusoro nepamativi ekamuri rekuita panguva yekukura, izvo zvinogona kugadziriswa nekugadzirisa maitiro ekugadzirisa nguva nenguva ekushandisa girafiti yekamuri rekuita.

 

Chikanganiso chetatu

I 3C-SiC polytype inclusion inotambanukira pamusoro peSiC epilayer ichitevedza gwara repasi, sezvakaratidzwa muMufananidzo 4g. Inogona kugadzirwa nezvidimbu zvinowira pamusoro peSiC epilayer panguva yekukura kwe epitaxial. Zvikamu izvi zvinoiswa mu epilayer uye zvinokanganisa maitiro ekukura, zvichikonzera 3C-SiC polytype inclusions, iyo inoratidza hunyanzvi hwepamusoro hwetriangular hwakapinza nezvidimbu zviri pamucheto wenzvimbo yetriangular. Zvidzidzo zvakawanda zvakatiwo mavambo e polytype inclusions akakonzerwa nekukwenya kwepamusoro, micropipes, uye parameter dzisina kunaka dzemaitiro ekukura.

 

Kukanganisika kwemakaroti

Karoti kakakanganisika imhando ye stacking fault complex ine magumo maviri ari paTSD neSF basal crystal planes, inogumiswa neFrank-type dislocation, uye saizi yekaroti kakakanganisika ine chekuita ne prismatic stacking fault. Kusanganiswa kwezvinhu izvi kunoumba chimiro chepamusoro chekaroti kakakanganisika, icho chinotaridzika sechimiro chekaroti chine density iri pasi pe1 cm-2, sezvakaratidzwa muMufananidzo 4f. Karoti kakakanganisika kanoumbwa nyore nyore pakukwenya, TSD, kana substrate defects.

 

Kukwenya

Kukwenya ndiko kukuvadzwa kwemuchina pamusoro pemawafer eSiC anogadzirwa panguva yekugadzira, sezvakaratidzwa muMufananidzo 4h. Kukwenya pasi peSiC substrate kunogona kukanganisa kukura kwe epilayer, kugadzira mutsara wekukanganiswa kwakanyanya mukati me epilayer, kana kukwenya kunogona kuva hwaro hwekuumbwa kwezvikanganiso zvekaroti. Saka, zvakakosha kukwenya mawafer eSiC zvakanaka nekuti kukwenya uku kunogona kukanganisa mashandiro emudziyo kana akaonekwa munzvimbo inoshanda yemudziyo.

 

Zvimwe zvikanganiso zvechimiro chepamusoro

Kuumbwa kwematanho (step bunching) idambudziko rinovapo panguva yekukura kweSiC epitaxial, iro rinoburitsa matriangles asina kusimba kana kuti trapezoidal pamusoro peSiC epilayer. Kune mamwe madambudziko akawanda pamusoro, akadai semakomba epamusoro, mapundu nemavanga. Matambudziko aya anowanzo kukonzerwa nekukura kusina kunaka uye kubviswa kwakakwana kwekupolisha, izvo zvinokanganisa mashandiro emudziyo.