Kutanga, chimiro uye zvivakwa zveSiC crystal.
SiC ibhinari komboni inoumbwa neSi element uye C element muchiyero che1: 1, kureva, 50% silicon (Si) uye 50% kabhoni (C), uye yayo yekutanga structural unit iSI-C tetrahedron.
Schematic diagram yesilicon carbide tetrahedron chimiro
Semuenzaniso, maatomu eSi akakura mudhayamita, akaenzana neapuro, uye C maatomu madiki mudhayamita, akaenzana neorenji, uye nhamba yakaenzana yemaranjisi nemaapuro zvinounganidzwa pamwechete kuita SiC crystal.
SiC is A binary compound, umo iyo Si-Si bond atomi spacing iri 3.89 A, sei kunzwisisa iyi spacing? Parizvino, iyo yakanyanya kunaka lithography muchina pamusika ine lithography kurongeka kwe3nm, inova chinhambwe che30A, uye iyo lithography yechokwadi ka8 iyo yeatomu chinhambwe.
Iyo Si-Si bond simba ndeye 310 kJ / mol, saka iwe unogona kunzwisisa kuti chisungo chesimba isimba rinokwevera aya maatomu maviri, uye iyo yakakura chisungo simba, iyo yakakura simba raunoda kudhonza.
Semuenzaniso, maatomu eSi akakura mudhayamita, akaenzana neapuro, uye C maatomu madiki mudhayamita, akaenzana neorenji, uye nhamba yakaenzana yemaranjisi nemaapuro zvinounganidzwa pamwechete kuita SiC crystal.
SiC is A binary compound, umo iyo Si-Si bond atomi spacing iri 3.89 A, sei kunzwisisa iyi spacing? Parizvino, iyo yakanyanya kunaka lithography muchina pamusika ine lithography kurongeka kwe3nm, inova chinhambwe che30A, uye iyo lithography yechokwadi ka8 iyo yeatomu chinhambwe.
Iyo Si-Si bond simba ndeye 310 kJ / mol, saka iwe unogona kunzwisisa kuti chisungo chesimba isimba rinokwevera aya maatomu maviri, uye iyo yakakura chisungo simba, iyo yakakura simba raunoda kudhonza.
Schematic diagram yesilicon carbide tetrahedron chimiro
Semuenzaniso, maatomu eSi akakura mudhayamita, akaenzana neapuro, uye C maatomu madiki mudhayamita, akaenzana neorenji, uye nhamba yakaenzana yemaranjisi nemaapuro zvinounganidzwa pamwechete kuita SiC crystal.
SiC is A binary compound, umo iyo Si-Si bond atomi spacing iri 3.89 A, sei kunzwisisa iyi spacing? Parizvino, iyo yakanyanya kunaka lithography muchina pamusika ine lithography kurongeka kwe3nm, inova chinhambwe che30A, uye iyo lithography yechokwadi ka8 iyo yeatomu chinhambwe.
Iyo Si-Si bond simba ndeye 310 kJ / mol, saka iwe unogona kunzwisisa kuti chisungo chesimba isimba rinokwevera aya maatomu maviri, uye iyo yakakura chisungo simba, iyo yakakura simba raunoda kudhonza.
Semuenzaniso, maatomu eSi akakura mudhayamita, akaenzana neapuro, uye C maatomu madiki mudhayamita, akaenzana neorenji, uye nhamba yakaenzana yemaranjisi nemaapuro zvinounganidzwa pamwechete kuita SiC crystal.
SiC is A binary compound, umo iyo Si-Si bond atomi spacing iri 3.89 A, sei kunzwisisa iyi spacing? Parizvino, iyo yakanyanya kunaka lithography muchina pamusika ine lithography kurongeka kwe3nm, inova chinhambwe che30A, uye iyo lithography yechokwadi ka8 iyo yeatomu chinhambwe.
Iyo Si-Si bond simba ndeye 310 kJ / mol, saka iwe unogona kunzwisisa kuti chisungo chesimba isimba rinokwevera aya maatomu maviri, uye iyo yakakura chisungo simba, iyo yakakura simba raunoda kudhonza.
Tinoziva kuti chinhu chose chinoumbwa nemaatomu, uye chimiro chekristaro kurongeka kwenguva dzose kwemaatomu, inodaidzwa kuti kurongeka kwenguva refu, sezvinotevera. Iyo diki yekristaro unit inonzi sero, kana sero iri cubic chimiro, inonzi yakavharwa-yakazara cubic, uye sero iri hexagonal dhizaini, inonzi yakavharwa-yakazara hexagonal.
Common SiC crystal marudzi anosanganisira 3C-SiC, 4H-SiC, 6H-SiC, 15R-SiC, etc. Kutevedzana kwavo kwekugadzirisa mu c axis direction inoratidzwa mumufananidzo.
Pakati pavo, iyo yakakosha stacking sequence ye4H-SiC ndeye ABCB... ; The basic stacking sequence ye6H-SiC is ABCACB... ; The basic stacking sequence ye15R-SiC is ABCACBCABACABCB... .
Izvi zvinoonekwa sechidhinha chekuvakisa imba, zvimwe zvidhinha zvemba zvine nzira nhatu dzekuzviisa, dzimwe dzine nzira ina dzekuisa, dzimwe dzine nzira nhanhatu.
Iwo ekutanga maseru ma paramita eaya akajairwa SiC makristasi marudzi anoratidzwa patafura:
A, b, c nemakona zvinorevei? Chimiro chediki diki unit cell muSiC semiconductor inotsanangurwa seizvi:
Muchiitiko chesero rimwe chete, chimiro chekristaro chichave chakasiyana, izvi zvakafanana nekutenga lottery, nhamba yekukunda ndeye 1, 2, 3, wakatenga 1, 2, 3 nhamba nhatu, asi kana nhamba yacho yakarongedzwa. zvakasiyana, mari yekukunda yakasiyana, saka nhamba uye kurongeka kwekrisiti imwechete, inogona kunzi kristaro yakafanana.
Iyi inotevera nhamba inoratidza maviri akajairwa stacking modes, chete mutsauko mune stacking modhi yemaatomu epamusoro, chimiro chekristaro chakasiyana.
Iyo crystal chimiro chakaumbwa neSiC chine hukama zvakanyanya nekushisa. Pasi pekuita kwekushisa kwakanyanya kwe1900 ~ 2000 ℃, 3C-SiC inoshanduka zvishoma nezvishoma kuita hexagonal SiC polyform yakadai se6H-SiC nekuda kwekusagadzikana kwayo kwemaitiro. Izvo chaizvo nekuda kwekubatana kwakasimba pakati pekugona kuumbwa kweSiC polymorphs uye tembiricha, uye kusagadzikana kwe3C-SiC pachayo, kukura kwe3C-SiC kwakaoma kuvandudza, uye kugadzirira kwakaoma. Iyo hexagonal system ye4H-SiC uye 6H-SiC ndiyo yakajairika uye iri nyore kugadzirira, uye inodzidzwa zvakanyanya nekuda kwehunhu hwavo.
Kureba kwechisungo cheSI-C bond muSiC crystal inongova 1.89A, asi simba rekubatanidza rinosvika 4.53eV. Naizvozvo, mukaha wesimba pakati penyika yekubatana uye nyika inopesana nekubatana yakakura kwazvo, uye bhendi rakakura rinogona kuumbwa, iro rakapetwa kanoverengeka iro reSi neGaAs. Iyo yepamusoro bhendi gap upamhi inoreva kuti yakakwirira-tembiricha yekristaro chimiro yakagadzikana. Iwo akabatana emagetsi emagetsi anogona kuona hunhu hwekushanda kwakagadzikana pakupisa kwakanyanya uye kurerutsa kupisa kwekupisa chimiro.
Kusunga kwakasimba kweSi-C bond kunoita kuti lattice ive nehigh vibration frequency, kureva kuti, high energy phonon, zvinoreva kuti SiC crystal ine yakakwira saturated electron mobility uye thermal conductivity, uye magetsi ane chekuita nemagetsi ane yakakwirira switching kumhanya uye kuvimbika, izvo zvinoderedza njodzi yekutadza kupisa kwemudziyo. Uye zvakare, iyo yakakwira yekuparara kwemunda simba reSiC inoibvumira kuti iwane yakakwira doping concentrations uye ine yakaderera pa-resistance.
Chechipiri, nhoroondo yeSiC crystal development
Muna 1905, Dr. Henri Moissan vakawana kristaro chaiyo yeSiC mugomba, iyo yaakawana yakafanana nedhaimondi ndokuritumidza kuti dhaimondi reMosan.
Muchokwadi, kare muna 1885, Acheson akawana SiC nekusanganisa coke ne silica nekuipisa muchoto chemagetsi. Panguva iyoyo vanhu vaifunga kuti musanganiswa wemadhaimondi uye vaiti emery.
Muna 1892, Acheson akavandudza maitiro ekugadzira, akasanganisa jecha requartz, coke, shoma shoma yehuni machipisi neNaCl, ndokuipisa muchoto chemagetsi arc kusvika 2700 ℃, uye akabudirira kuwana scaly SiC crystals. Iyi nzira yekugadzira SiC makristasi inozivikanwa senzira yeAcheson uye ichiri nzira huru yekugadzira SiC abrasives muindasitiri. Nekuda kwekuchena kwakadzikira kwezvakagadzirwa mbishi uye rough synthesis process, Acheson nzira inogadzira yakawanda SiC tsvina, yakashata crystal kutendeseka uye diki dhayamita yekristaro, izvo zvakaoma kuzadzisa zvinodiwa neindasitiri yesemiconductor yehukuru-hukuru, hutsanana uye hurefu. -makristasi emhando, uye haigone kushandiswa kugadzira zvigadzirwa zvemagetsi.
Lely wePhilips Laboratory akaronga nzira itsva yekukura SiC single crystals muna 1955. Munzira iyi, graphite crucible inoshandiswa semudziyo wekukura, SiC powder crystal inoshandiswa seyakasvibiswa yekukura SiC crystal, uye porous graphite inoshandiswa kuparadzanisa. nzvimbo ine gomba kubva pakati pechirimwa mbishi. Kana ichikura, iyo graphite crucible inopisa kusvika ku2500 ℃ pasi pemhepo yeAr kana H2, uye iyo yeperipheral SiC poda inoderedzwa uye yakasvibiswa kuita Si uye C vapor chikamu zvinhu, uye iyo SiC crystal inokura munzvimbo yepakati nepakati mushure megesi. kuyerera kunoparidzirwa kuburikidza ne porous graphite.
Chechitatu, SiC crystal kukura tekinoroji
Iyo imwe chete crystal kukura kweSiC yakaoma nekuda kwehunhu hwayo. Izvi zvinonyanya kukonzerwa nekuti hapana nhanho yemvura ine stoichiometric reshiyo yeSi: C = 1: 1 pamhepo yemhepo, uye haigone kukura nenzira dzakakura dzekukura dzinoshandiswa neiyozvino mainstream process yekukura kweiyo semiconductor. indasitiri - cZ nzira, inodonha crucible nzira uye dzimwe nzira. Maererano nekuverenga kwemaoretical, chete kana kumanikidza kuri kukuru kupfuura 10E5atm uye tembiricha yakakwira kupfuura 3200 ℃, chiyero che stoichiometric cheSi: C = 1: 1 mhinduro inogona kuwanikwa. Kuti vakunde dambudziko iri, masayendisiti akaita nhamburiko dzisingaperi dzekukurudzira nzira dzakasiyana dzekuwana mhando yepamusoro yekristaro, saizi yakakura uye yakachipa yeSiC makristasi. Parizvino, nzira huru iPVT nzira, yemvura chikamu nzira uye yakanyanya tembiricha vapor kemikari deposition nzira.
Nguva yekutumira: Jan-24-2024