Silicon hlau yog cais li cas
"Silicon hlau" (tseem hu ua kev lag luam silicon hauv Suav teb) yog lub npe lag luam uas tshwm sim hauv nruab nrab -1960s. Nws qhov tshwm sim tau cuam tshuam nrog kev nce ntawm kev lag luam semiconductor. Kev coj ua thoob ntiaj teb yog faib cov lag luam silicon rau hauv silicon hlau thiab silicon rau semiconductors. Silicon hlau yog ib yam khoom uas ua los ntawm quartz thiab coke smelted nyob rau hauv ib tug hluav taws xob cua sov rauv, nrog rau cov ntsiab lus ntawm lub ntsiab Cheebtsam silicon ntawm txog 98 feem pua (99.99 feem pua Si kuj muaj nyob rau hauv silicon hlau), thiab cov seem impurities yog hlau, txhuas, calcium, thiab lwm yam. Semiconductor silicon yog siv los ua cov purity silicon hlau rau cov khoom siv semiconductor. Nws yog muag hauv polycrystalline thiab monocrystalline cov ntaub ntawv, nrog rau yav tas los pheej yig thiab tom kawg kim. Nws muab faib ua ntau yam specifications nyob ntawm seb nws siv. Raws li kev txheeb cais, lub ntiaj teb tau siv txog 500,{5}} tons ntawm silicon hlau hauv xyoo 1985, ntawm 60 feem pua yog siv rau txhuas alloys, tsawg dua 30 feem pua yog siv rau cov organic silicon, li 3 feem pua yog siv rau semiconductors. , thiab tus so yog siv rau steel smelting thiab precision ceramics, thiab lwm yam.
Kev faib tawm ntawm silicon hlau feem ntau yog raws li cov ntsiab lus ntawm peb lub ntsiab impurities ntawm hlau, txhuas thiab calcium uas muaj nyob rau hauv silicon hlau muaj pes tsawg leeg. Raws li cov ntsiab lus ntawm hlau, txhuas thiab calcium hauv silicon hlau, silicon hlau tuaj yeem muab faib ua ntau qib xws li 553, 441, 411, 421, 3303, 3305, 2202, 2502, 1501 thiab 1101.
Industrially, silicon hlau feem ntau yog tsim los ntawm kev txo cov silicon dioxide los ntawm cov pa roj carbon nyob rau hauv lub cub hluav taws xob. Cov tshuaj tiv thaiv kab mob sib npaug: SiO2 ntxiv rau 2C → Si ntxiv rau 2CO Cov silicon yog li ua tau yog 97-98 feem pua ntshiab thiab hu ua silicon hlau. Tom qab ntawd nws yog melted thiab recrystallized, thiab impurities raug tshem tawm nrog kua qaub kom tau silicon hlau nrog ib tug purity ntawm 99.7 ~ 99.8 feem pua.
Silicon hlau yog tsim los ntawm silicon, yog li nws muaj cov khoom zoo sib xws rau silicon. Muaj ob isomers ntawm silicon, amorphous silicon thiab crystalline silicon. Amorphous silicon yog cov hmoov greyish-dub thiab yog ib qho microcrystal. Crystalline silicon muaj cov qauv siv lead ua thiab cov khoom siv semiconductor ntawm pob zeb diamond, nrog lub melting point ntawm 1410 degree, boiling point ntawm 2355 degree, ib tug Mohs hardness ntawm 7, thiab ib tug nkig xwm. Amorphous silicon yog tshuaj lom neeg thiab tuaj yeem hlawv hnyav hauv oxygen. Nws reacts nrog halogens, nitrogen, carbon thiab lwm yam uas tsis yog-hlau nyob rau hauv high kub, thiab muaj peev xwm kuj cuam tshuam nrog magnesium, calcium, hlau thiab lwm yam hlau los tsim silicides. Amorphous silicon yog insoluble nyob rau hauv yuav luag tag nrho cov inorganic thiab organic acids, nrog rau hydrofluoric acid, tab sis muaj peev xwm yaj nyob rau hauv ib tug sib tov ntawm nitric acid thiab hydrofluoric acid. Concentrated sodium hydroxide tov tuaj yeem yaj amorphous silicon thiab tso cov roj hydrogen. Crystalline silicon yog qhov tsis ua haujlwm thiab tsis muaj tshuaj lom neeg ua ke nrog cov pa oxygen txawm tias kub. Nws kuj yog insoluble nyob rau hauv txhua yam inorganic thiab organic acids, tab sis yog soluble nyob rau hauv ib tug sib tov ntawm nitric acid thiab hydrofluoric acid raws li zoo raws li nyob rau hauv concentrated sodium hydroxide daws.
