CVD silicon carbide coating-2

CVD silicon carbide coating

1. Nei pane asilicon carbide coating

Iyo epitaxial layer ndeye chaiyo imwe chete crystal yakaonda firimu yakakura pahwaro hwewaferi kuburikidza neiyo epitaxial process. Iyo substrate wafer uye epitaxial yakaonda firimu yakaungana inonzi epitaxial wafers. Pakati pavo, thesilicon carbide epitaxiallayer inokura pane conductive silicon carbide substrate kuti iwane silicon carbide homogeneous epitaxial wafer, iyo inogona kugadzirwazve kuita zvishandiso zvemagetsi seSchottky diodes, MOSFETs, uye IGBTs. Pakati pavo, inonyanya kushandiswa ndeye 4H-SiC substrate.

Sezvo zvese zvishandiso zvinonyatso zivikanwa pane epitaxy, mhando yeepitaxyine simba guru pakushanda kwechigadzirwa, asi hutano hwe epitaxy hunobatwa nekugadzirisa makristasi uye substrates. Iyo iri pakati pekubatanidza indasitiri uye inoita basa rakakosha mukusimudzira indasitiri.

Nzira huru dzekugadzirira silicon carbide epitaxial layers ndeidzi: evaporation kukura nzira; liquid phase epitaxy (LPE); molecular beam epitaxy (MBE); Chemical vapor deposition (CVD).

Pakati pavo, kemikari vapor deposition (CVD) ndiyo inonyanya kufarirwa 4H-SiC homoepitaxial nzira. 4-H-SiC-CVD epitaxy kazhinji inoshandisa CVD midziyo, iyo inogona kuve nechokwadi kuenderera kweiyo epitaxial layer 4H crystal SiC pasi pekukura kwakanyanya kwekushisa.

Mumidziyo yeCVD, iyo substrate haigone kuiswa zvakananga pasimbi kana kungoiswa pachigadziko che epitaxial deposition, nekuti inosanganisira zvinhu zvakasiyana-siyana senge gasi kuyerera kwekutungamira (yakatwasuka, yakatwasuka), tembiricha, kudzvanywa, kugadzirisa, uye kudonha zvinosvibisa. Naizvozvo, chigadziko chinodiwa, uye ipapo substrate inoiswa pa diski, uye ipapo epitaxial deposition inoitwa pane substrate uchishandisa CVD tekinoroji. Iyi nheyo ndiyo SiC yakavharwa graphite base.

Sechikamu chepakati, iyo graphite base ine hunhu hwesimba rakananga uye yakananga modulus, yakanaka yekupisa kuvhunduka kusagadzikana uye kushora kuramba, asi panguva yekugadzira, iyo graphite ichave yakasvibiswa uye iine hupfu nekuda kwekusara kwemagasi anoparadza uye simbi organic. nyaya, uye hupenyu hwebasa hweiyo graphite base huchadzikiswa zvakanyanya.

Panguva imwecheteyo, iyo yakawa graphite poda ichasvibisa chip. Mukugadzirwa kwesilicon carbide epitaxial wafers, zvakaoma kuzadzisa zvinodiwa nevanhu zvinowedzera kuomesera pakushandisa magirafu zvinhu, izvo zvinotadzisa zvakanyanya kukura kwayo uye kushanda kwayo. Naizvozvo, tekinoroji yekupfeka yakatanga kusimuka.

2. ZvakanakiraSiC coating

Izvo zvemuviri uye zvemakemikari zvimiro zvejasi zvine zvakaomesesa zvinodiwa zvekupisa tembiricha kuramba uye corrosion resistance, izvo zvinokanganisa zvakananga goho uye hupenyu hwechigadzirwa. SiC zvinhu zvine simba rakawanda, kuomarara kwakanyanya, kuderera kwekuwedzera kwemafuta coefficient uye yakanaka yekupisa conductivity. Icho chakakosha chepamusoro-tembiricha chimiro chechimiro uye yakakwirira-tembiricha semiconductor zvinhu. Inoshandiswa kune graphite base. Zvayakanakira ndezvekuti:

-SiC inodzivirira corrosion uye inogona kunyatsoputira graphite base, uye ine density yakanaka kudzivirira kukuvara negasi rinoparadza.

-SiC ine high thermal conductivity uye yakakwirira yekubatanidza simba ne graphite base, kuve nechokwadi kuti kuvhara hakusi nyore kudonha mushure mekuwanda kwepamusoro-kupisa uye kuderera-kupisa.

-SiC ine kugadzikana kwakanaka kwemakemikari kudzivirira kuvhara kubva mukukundikana mumhepo yepamusoro-yekushisa uye inopisa.

Mukuwedzera, epitaxial furnaces yezvinhu zvakasiyana zvinoda magirafu matireyi ane zviratidzo zvakasiyana-siyana zvekushanda. Iyo yekupisa yekuwedzera coefficient yekufananidza yegraphite zvinhu inoda kuchinjika kune yekukura tembiricha ye epitaxial furnace. Semuyenzaniso, tembiricha yesilicon carbide epitaxial kukura yakakwira, uye tireyi ine yakakwira yekupisa yekuwedzera coefficient matching inodiwa. Iyo yekupisa yekuwedzera coefficient yeSiC iri padhuze neiyo yegraphite, ichiita kuti ive yakakodzera sechinhu chinosarudzika chekuputira pamusoro peiyo graphite base.
Zvigadzirwa zveSiC zvine mafomu akasiyana ekristaro, uye anonyanya kuzivikanwa ndeye 3C, 4H uye 6H. Mhando dzakasiyana dzekristaro dzeSiC dzine mashandisiro akasiyana. Semuenzaniso, 4H-SiC inogona kushandiswa kugadzira michina ine simba guru; 6H-SiC ndiyo yakanyanya kugadzikana uye inogona kushandiswa kugadzira optoelectronic zvishandiso; 3C-SiC inogona kushandiswa kugadzira GaN epitaxial layers uye kugadzira SiC-GaN RF zvishandiso nekuda kwechimiro chayo chakafanana neGaN. 3C-SiC inowanzonziwo β-SiC. Kushandiswa kwakakosha kwe β-SiC senge firimu rakatetepa uye coating zvinhu. Naizvozvo, β-SiC parizvino ndiyo huru zvinhu zvekupfeka.
SiC coatings inowanzoshandiswa mukugadzira semiconductor. Iwo anonyanya kushandiswa mu substrates, epitaxy, oxidation diffusion, etching uye ion implantation. Izvo zvemuviri uye zvemakemikari zvimiro zvejasi zvine zvakaomesesa zvinodikanwa pane yakakwirira tembiricha kuramba uye corrosion kuramba, izvo zvinokanganisa zvakananga goho uye hupenyu hwechigadzirwa. Naizvozvo, kugadzirira kweSiC coating kwakakosha.